Eur J Anaesthesiol 2014; 31:236–245
CORRESPONDENCE Accidental intra-arterial injection of paracetamol Different preparations, different results Sukhen Samanta, Nilanchal Chakraborty and Sujay Samanta From the Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India Correspondence to Dr Sukhen Samanta, Sanjay Gandhi Postgraduate Institute of Medical Sciences, New PG Hostel, Room No. 218, Lucknow 226014, India Tel: +91 08 00 496 7745; e-mail: [email protected] Published online 27 June 2013
Editor, Accidental intra-arterial injections of some anaesthetic drugs may cause arterial spasm with negative consequences.1 Similarly, there are drugs which are given unintentionally or intentionally without such consequences.2 For obvious reasons, controlled trials that may elucidate the pathophysiology underlying arterial spasm after intra-arterial injection cannot be performed.2 We report two cases of unintentional intra-arterial injection of different preparations of paracetamol with different outcomes. As far as we know, adverse outcome after intra-arterial injection of paracetamol has not been reported so far. The patient (case 1) and the patient’s father (case 2) reviewed the case reports and gave written permission for publication. A 42-year-old man was scheduled for laparoscopic cholecystectomy. At the end of surgery, he was accidentally given a benzyl alcohol-based preparation of paracetamol 900 mg intra-arterially for postoperative pain relief. Following recovery from anaesthesia, he complained about pain in his right hand. The search for the cause of that pain revealed the unintentional paracetamol injection through an extension line attached to a catheter in the right radial artery. Bluish discolouration was noted on two fingers in the radial artery distribution 40 min after the injection. Treatment was initiated with intra-arterial heparin 5000 IU and intravenous lidocaine 60 mg. Despite this, gangrene developed. Three days after the accidental intra-articular injection, he had to undergo amputation of the distal part of his affected fingers, although, on radiological examination, the brachial arterial cross-section area and flow was normal (Fig. 1). A 7-year-old boy (bodyweight 22 kg) was scheduled for a craniotomy for medulloblastoma. Accidentally, an aqueous-based preparation of paracetamol 350 mg (Perfalgan 10 mg ml1) was given into a radial artery in
the postoperative period. The patient stayed asymptomatic; the incidence was only identified during the routine postoperative round. Doppler sonography revealed normal radial arterial pulse waves after a 7-day follow-up. The paracetamol preparations had a similar pH. Previously, drugs dissolved in mannitol (for instance vecuronium) had been used safely by the intra-arterial route.3 We assume that in the first case, the benzyl alcohol preservative that was used in the nonaqueous preparation of paracetamol may have caused the vasospasm, leading to endothelial oedema and capillary endothelial dysfunction.4 Complications of intra-arterial injection of nonaqueous agents (phenytoin, propofol)5 and highly alkaline drugs (thiopentone)1 have been known for years. On the contrary, drugs like atropine, pancuronium or fentanyl have been injected intra-arterially without untoward effects.5 Membrane-soluble drugs are known to cause more complications.4 Multiple theories have been postulated to explain the arterial spasm, or hypoperfusion which is the final common pathway for limb ischaemia. Unintentional (iatrogenic or accidental) intra-arterial injections may occur in the early postoperative period when patients are recovering from anaesthesia. In our first case, the dramatic outcome was due to benzyl alcohol preservative but not the paracetamol itself. Consequently, drugs containing benzyl alcohol must not be injected intra-arterially. Finally, every country should have a strict drug control system that prevents inappropriate mixing of drugs and preservatives, and that stops ‘home made’ practices Fig. 1
Hand showing gangrene along the radial artery distribution.
0265-0215 ß 2014 Copyright European Society of Anaesthesiology
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Correspondence
to ensure patient safety. Although the intra-articular administration of an aqueous-based preparation of paracetamol did not cause any harm, the intra-arterial injection of any paracetamol solution should be prevented.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: none.
References 1 2
3 4 5
Stone HH, Donnelly CC. The accidental intra-arterial injection of thiopental. Anesthesiology 1961; 22:995–1006. Ghouri AF, Mading W, Prabaker K. Accidental intraarterial drug injection via intravascular catheters placed on the dorsum of the hand. Anesth Analg 2002; 95:487–491. Lee JY, Choi JH, Yoon JH. Accidental intra-arterial injection of vecuronium: a case report. Korean J Anesthesiol 2004; 47:917–919. Knill RL, Evans D. Pathogenesis of gangrene following intra-arterial injection of drugs: a new hypothesis. Can Anaesth Soc J 1975; 22:637–646. Fikkers BG, Wuis EW, Wijnen MH, Scheffer GJ. Intra-arterial injection of anesthetic drugs. Anesth Analg 2006; 103:792–794. DOI:10.1097/EJA.0b013e328363163c
Anaesthesiological support in a cardiac electrophysiology laboratory Aaron Conway From the Institute of Health & Biomedical Innovation, Brisbane, Queensland, Australia Correspondence to Dr Aaron Conway, Institute of Health & Biomedical Innovation, Queensland University of Technology, Level 7, 60 Musk Ave, Kelvin Grove, Brisbane, QLD 4064, Australia Tel: +61 7 3138 6124; e-mail: [email protected] Published online 23 November 2013
Editor, I read with great interest the article by Trouve-Buisson et al.1 that was recently published in the European Journal of Anaesthesiology describing the anaesthetic management during implantation of cardiovascular implantable electronic devices (CIEDs). The authors noted that their results presented new evidence in the recent debate about sedation by nonanaesthesiologists and went on to state that as severe complications represented almost one-third of the overall complication rate, direct supervision by a nurse anaesthetist or anaesthesiologist seems to be required. As the debate is in regard to sedation by nonanaesthesiologists not general anaesthetic by nonanaesthesiologists, the statistic presented to support the authors’ argument is misleading.2 It was reported that 26% (n ¼ 63) of the patients who received deep sedation had at least one complication and 4% (n ¼ 10)
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experienced a severe complication. Therefore, of the 63 deeply sedated patients who had a complication, in only 16% (n ¼ 10) of patients was it severe. In contrast, 71% (n ¼ 15) of general anaesthetic patients had a complication and of these patients, in 11 (73%) the complication was severe. On the basis of the drastically disparate complication rates between patients who received general anaesthesia and those who received deep sedation, it does not seem reasonable for the same conclusion to be drawn for both groups of patients. Also, considering the authors noted that their study presented new evidence in the recent debate about sedation by nonanaesthesiologists, it is surprising that the complication rate of the patients who received deep sedation with propofol in this study was not considered in relation to a recent similar study, which involved the administration of propofol by nonanaesthesiologists.3 Sayfo et al.3 reported the frequency of adverse events during proceduralist-directed nurse-administered propofol sedation (PDNAPS) during the implantation of cardiac implantable electronic devices. Interestingly, a higher incidence of both mild (38.7%) and severe complications (10%) was reported in this study.1,3 Potentially then, administration of propofol for deep sedation during the implantation of cardiac implantable electronic devices by anaesthesiologists (or nurse anaesthetists) may actually be associated with decreased risk of complications. Therefore, an adequately powered randomised controlled trial would be required to draw strong conclusions for or against the use of PDNAPS during the implantation of cardiac implantable electronic devices. Yet, the authors noted that on the basis of their findings, such a trial may be unethical. It should be noted that recent surveys of sedation practice in the United States of America and also Australia and New Zealand indicated that PDNAPS is actually already being utilised in practice.4,5 Furthermore, gaining access to monitored anaesthesia care for sedation in the cardiac catheterisation laboratory is difficult in many institutions around the world.4,5 Moreover, the need for more effective sedative and analgesic medications for cardiovascular procedures than the typical benzodiazepine and opioids combination that can be safely administered without an anaesthetist present has been recently observed and is also the subject of numerous recent investigations.3,6,7 For these reasons, in contrast to the authors’ opinion that trials comparing nonanaesthesiologist with anaesthesiologist managed sedation may be unethical, the evidence at hand indicates that such trials are indeed required.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: none.
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238 Correspondence
References 1
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Trouve-Buisson T, Arvieux L, Bedague D, et al. Anaesthesiological support in a cardiac electrophysiology laboratory: a single-centre, prospective observational study. Eur J Anaesthesiol 2013; 30:1–6. Conway AW, Page K, Rolley JX, Worrall-Carter L. Nurseadministered procedural sedation and analgesia in the cardiac catheter laboratory: an integrative review. Int J Nurs Studies 2011; 48:1012–1023. Sayfo S, Vakil KP, Alqaqa’a A, et al. A retrospective analysis of proceduralist-directed, nurse-administered propofol sedation for implantable cardioverter-defibrillator procedures. Heart Rhythm 2012; 9:342–346. Conway A, Rolley JX, Page K, Fulbrook P. Trends in nurse-administered procedural sedation and analgesia across Australian and New Zealand cardiac catheterisation laboratories: results of an electronic survey. Aust Crit Care 2013. DOI:10.1016/j.aucc.2013.05.003. Gaitan BD, Trentman TL, Fassett SL, et al. Sedation and analgesia in the cardiac electrophysiology laboratory: a national survey of electrophysiologists investigating the who, how, and why? J Cardiothor Vasc Anesth 2011; 25:647–659. Conway A, Rolley JX, Fulbrook P, Page K. Issues and challenges associated with nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory: a qualitative study. J Clin Nurs 2013; [Epub ahead of print]. DOI:10.1111/jocn.12147. Dupanovic´ M, Lakkireddy D, Emert MP, Krebill R. Utility of dexmedetomidine in sedation for radiofrequency ablation of atrial fibrillation. J Perianesth Nurs 2013; 28:144–150. DOI:10.1097/EJA.0000000000000032
Reply to: anaesthesiological support in a cardiac electrophysiology laboratory Thibaut Trouve´-Buisson and Pierre Albaladejo From the Department of Anaesthesia and Intensive Care Medicine, Grenoble University Hospital, La Tronche, Ise`re, France Correspondence to Trouve´-Buisson, MD, Department of Anaesthesia and Intensive Care Medicine, Grenoble University Hospital, 38700 La Tronche, Ise`re, France Tel: +334 7676 9288; e-mail: [email protected] Published online 27 November 2013
did not specifically analyse the subgroup of patients undergoing general anaesthetic. Moreover, we are clearly inclined to think that the choice of the anaesthetic procedure is part of the anaesthetic care. To our knowledge, there is no efficient system described in the literature to direct safely ‘low-risk’ patients to nonanaesthetic care and ‘high-risk’ patients to an anaesthetist. Finally, we believe that even the subgroup of deeply sedated patients with its overall complication rate of 26% and severe complication rate of 4% must receive anaesthetic attention. Second, concerning the remark of Dr Conway that randomised controlled trials are needed, we would argue that it will be difficult to design such a study comparing two systems: anaesthesia care by trained staff (nurse anaesthetist and anaesthesiologist) with a specific training for propofol administration by nurses or cardiologists. In the second one, a failure in the training process or an unusual complication would imply the intervention of an anaesthesiologist or intensivist. Third, comparing this cohort with other studies seemed difficult because of different definitions of severe complications, study designs and sedation protocols (particularly propofol-associated drugs)2,3 or differences in the procedures requiring sedation.4 Our cohort included only patients requiring cardiovascular implantable electronic devices management and excluded radiofrequency catheter ablation. Finally, we do agree with Dr Conway that more research on this specific and very fragile population is necessary to eventually improve perioperative care.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none.
Editor,
Conflicts of interest: none.
We are grateful to Dr Conway for his thoughtful comments1 concerning our recently published study,2 and we are happy to provide the following answers to the issues that he has raised.
References
First, the relationship between general anaesthesia and complications cannot be easily interpreted in this cohort. General anaesthesia was often performed because of a particular risk of complications, mostly procedural (such as probe extraction), requiring complete immobility and/or at risk of the need for a rescue procedure. The aim of this cohort was to describe the complications rate and risk factors for the overall population admitted to our cardiac electrophysiology laboratory and thus we
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Conway A. Anaesthesiological support in a cardiac electrophysiology laboratory. Eur J Anaesthesiol 2014; 31:237–238. Trouve´-Buisson T, Arvieux L, Bedague D, et al. Anaesthesiological support in a cardiac electrophysiology laboratory: a single-centre, prospective observational study. Eur J Anaesthesiol 2013; 30: 658–663. Sayfo S, Vakil KP, Alqaqa’a A, et al. A retrospective analysis of proceduralist-directed, nurse-administered propofol sedation for implantable cardioverter-defibrillator procedures. Heart Rhythm 2012; 9:342–346. Dupanovic M, Lakkireddy D, Emert MP, Krebill R. Utility of dexmedetomidine in sedation for radiofrequency ablation of atrial fibrillation. J Perianesth Nurs 2013; 28:144–150. DOI:10.1097/EJA.0000000000000030
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ESA guidelines on the management of severe perioperative bleeding Comments on behalf of the Subcommittee on Transfusion and Haemostasis of the European Association of Cardiothoracic Anaesthesiologists Wulf Dietrich, David Faraoni, Christian von Heymann, Daniel Bolliger, Marco Ranucci, Michael Sander and Peter Rosseel From the Institute for Research in Cardiac Anaesthesia, Munich, Germany (WD), Department of Anaesthesiology, Queen Fabiola Children’s University Hospital, Brussels, Belgium (DF), Department of Anaesthesiology and Intensive Care Medicine, Charite´-Universita¨tsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany (CvH), University Hospital Basel, Department of Anaesthesia and Intensive Care Medicine, Basel, Switzerland (DB), Department of Cardiothoracic and Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy (MR), Department of Anaesthesiology and Intensive Care Medicine, Charite´-Universita¨tsmedizin Berlin, Campus Charite´ Mitte, Berlin, Germany (MS), and Department of Anaesthesia and Intensive Care, Amphia Hospital, Breda, The Netherlands (PR) Correspondence to Wulf Dietrich, Institute for Research in Cardiac Anesthesia, Winthirstr. 4, 80639 Munich, Germany Tel: +004989166199; e-mail: [email protected] Published online 27 November 2013
Editor, We read with interest the recent guidelines of the European Society of Anaesthesiology published in the June 2013 issue of the European Journal of Anaesthesiology.1 We congratulate the authors for putting their efforts together with the common aim to review the current literature and to write these recommendations. Indeed, more than 18 general and specific clinical settings were reviewed, leading to about 200 recommendations. However, we believe that for the specific setting of cardiac surgery, some important remarks should be made. The GRADE system used by the authors should be detailed and considered before guidelines can be applied in clinical practice. Indeed, only GRADE 1A and 1B are based on randomised trials in which benefit appears to outweigh risk. GRADE 1C relates to observational or low-quality randomised controlled trials. On the contrary, trials in which the benefit was closely balanced with risk are classified as GRADE 2. Considering this scoring system, all recommendations with GRADE >1B should be interpreted with caution and should not be considered as strong and clinically relevant until further evidence from sufficiently powered studies has been provided. Figure 1 summarises grades of recommendation drawn from the ESA guidelines. We found that the vast majority of the recommendations consisted of low-grade recommendations and therefore should be interpreted with caution. For example, the authors recommended the application of transfusion algorithms incorporating predefined intervention triggers to guide haemostatic therapy during intraoperative bleeding (GRADE 1C). We agree that an algorithm-based approach improves perioperative management of bleeding. However, it is not clear
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whether this benefit is due to the application of the algorithm itself or to the use of point-of-care monitoring (1C). Thus, an algorithm-based approach should be recommended, but further studies are needed to better define the benefit of using point-of-care devices, especially platelet function testing (2C). The authors recommend the administration of fibrinogen concentrates in different clinical settings. Rahe-Meyer et al.2 recently published the only randomised controlled trial that tested a well designed algorithm in cardiac surgery. Even if the results of this study argue that fibrinogen concentrates should be used as a first-line therapy, this study only included 29 patients who were treated with fibrinogen. Furthermore, in the Guidelines, the target fibrinogen level after cardiac surgery is recommended to be a maximum clot firmness of 22 mm in the FIBTEM tracing (p. 288). This target value has been investigated in two small nonrandomised studies including a total of 16 patients in whom a maximum clot firmness of 22 mm was targeted. In the fibrinogen concentrate supplemented patients, reduced blood loss and less transfusion requirements were observed.3,4 Furthermore, the suggested fibrinogen dose is a matter of concern. The authors recommend (2C) the administration of 25 to 50 mg kg1 fibrinogen. However, this arbitrary target level of 22 mm at FIBTEM was only reached in one study,4 with a median fibrinogen dose of 7.8 2.7 g (range, 5 to 13 g). Such high doses require support from sufficiently powered studies. In addition, the recommendation of a prophylactic preoperative infusion of 2 g fibrinogen concentrate in patients with fibrinogen concentration less than 3.8 g l1 comes from a retrospective analysis (N ¼ 98, CABG patients) by Blome et al.5 but could not be confirmed in a larger prospective study (N ¼ 170).6 Preoperative fibrinogen levels between transfused and nontransfused patient were not different, but postoperative fibrinogen levels were associated with blood loss, although this correlation was rather weak (r ¼ 0.53). This is too little evidence to support preoperative fibrinogen supplementation. Finally, we think that the Guidelines should have mentioned that, despite no clear safety concerns about thromboembolic complications of fibrinogen supplementation, the existing body of literature is not large enough to clearly exclude this potential risk. In conclusion, our committee agrees that the administration of fibrinogen concentrate may be associated with reduced blood loss and transfusion requirements in the perioperative period in patients undergoing cardiac surgery, but the dosing scheme, the fibrinogen level to be targeted and outcomes should be better studied in further large, well designed trials. There are at least four randomised trials on fibrinogen supplementation in cardiac surgery currently registered in clinicaltrials.gov, and
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240 Correspondence
Fig. 1
60
Number of recommendations
45
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0 1A
1B
1C
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2B
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A
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C
GRADE system Histogram summarising the number of recommendations corresponding to each GRADE cited in the Guidelines.
we suggest waiting for the results of these studies before sound recommendations are made. Almost the same concerns could be applied to the use of prothrombin complex concentrate. No prospective trial has compared the efficacy of prothrombin complex concentrate alone with other therapies in the perioperative period of cardiovascular surgery. Well designed, randomised controlled trials are needed before prothrombin complex concentrate may be recommended. The authors state that ‘goal-directed therapy with coagulation factor concentrates (fibrinogen and/or prothrombin complex concentrate) may reduce transfusion-associated costs in trauma, cardiac surgery and liver transplantation (B)’. Similar to the use of fibrinogen concentrate, EACTA’s Subcommittee of Transfusion and Haemostasis recommends considering these recommendations in clinical practice with extreme caution owing to the small amount of data that are available supporting the use of prothrombin complex concentrate in cardiac surgery. Apart from coagulation, these Guidelines have also addressed perioperative anaemia management. The Guidelines recommend (p. 217) ‘if iron deficiency has been ruled out, we suggest treating anaemic patients with erythropoietin-stimulating agents 2A’. The authors have clearly pointed out that a large body of prospective trials (N ¼ 18), systematic reviews, meta-analyses (N ¼ 3) and guidelines (N ¼ 1) has demonstrated the efficacy of human recombinant erythropoietin. With regard to the
clinical benefit outweighing the risks of erythropoietin treatment, there has been only one study so far that has shown an increased risk of thromboembolism in spinal surgery.7 In this study, thromboprophylaxis was not performed routinely as recommended. According to the GRADE system, the recommendation to treat anaemia should not be 2A, but at least 1B. In general conclusion, the Subcommittee on Transfusion and Haemostasis of EACTA would like to congratulate the European Society of Anaesthesiology for publishing this large review of the literature. However, we would like to draw attention to the fact that some recommendations in these Guidelines are only supported by small, and not always randomised studies. In particularly with respect to the use of coagulation factor concentrates, further prospective trials are needed before high-level recommendations can be made.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: WD: Formerly, consultant for Bayer Corp., Leverkusen, Germany, Consultant for The Medicines Company, Munich-Leipzig, Germany, Consultant for Nordic Pharma SAS, Paris, France. Formerly, study support from CSL Behring, Marburg, Germany. DF: no conflicts of interest. CvH: Within the last 3 years, CvH received speaker and/or consultancy honoraria from Bayer Healthcare, Boehringer Ingelheim, Pfizer GmbH, BMS,
Eur J Anaesthesiol 2014; 31:236–245 Copyright © European Society of Anaesthesiology. Unauthorized reproduction of this article is prohibited.
Correspondence
NovoNordisk Pharma, Nordic Pharma, The Medicines Company, Vifor Pharma and Janssen-Cilag as well as research support by CSL Behring, TEM International, Bayer Healthcare, Boehringer Ingelheim and Baxter. DB: received speaker honorarium from TEM International, Munich, Germany, and an unrestricted research grant from CSL Behring, Berne, Switzerland. MR: Within the last 3 years, MR received speaker and/or consultancy honoraria from NovoNordisk Pharma, The Medicines Company, CSL Behring, Grifols, Roche, Medtronic. DB received speaker honorarium from TEM International, Munich, Germany, and an unrestricted research grant from CSL Behring, Berne, Switzerland. MS: within the last 3 years, MS received research support from The Medicines Company and NovoNordisk Pharma. PR: no conflicts of interest.
References 1
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Kozek-Langenecker SA, Afshari A, Albaladejo P, et al. Management of severe perioperative bleeding: guidelines from the European Society of Anaesthesiology. Eur J Anaesthesiol 2013; 30:270–382. Rahe-Meyer N, Solomon C, Hanke A, et al. Effects of fibrinogen concentrate as first-line therapy during major aortic replacement surgery: a randomized, placebo-controlled trial. Anesthesiology 2013; 118:40–50. Rahe-Meyer N, Pichlmaier M, Haverich A, et al. Bleeding management with fibrinogen concentrate targeting a high-normal plasma fibrinogen level: a pilot study. Br J Anaesth 2009; 102:785–792. Rahe-Meyer N, Solomon C, Winterhalter M, et al. Thromboelastometryguided administration of fibrinogen concentrate for the treatment of excessive intraoperative bleeding in thoracoabdominal aortic aneurysm surgery. J Thorac Cardiovasc Surg 2009; 138:694–702. Blome M, Isgro F, Kiessling AH, et al. Relationship between factor XIII activity, fibrinogen, haemostasis screening tests and postoperative bleeding in cardiopulmonary bypass surgery. Thromb Haemost 2005; 93:1101– 1107. Karlsson M, Ternstrom L, Hyllner M, et al. Plasma fibrinogen level, bleeding, and transfusion after on-pump coronary artery bypass grafting surgery: a prospective observational study. Transfusion 2008; 48:2152– 2158. Stowell CP, Jones SC, Enny C, et al. An open-label, randomized, parallelgroup study of perioperative epoetin alfa versus standard of care for blood conservation in major elective spinal surgery: safety analysis. Spine 2009; 34:2479–2485. DOI:10.1097/EJA.0000000000000033
Reply to: ESA guidelines on the management of severe perioperative bleeding Sibylle A. Kozek-Langenecker, Georgina Imberger, Niels Rahe-Meyer, Arash Afshari, on behalf of the European Society of Anaesthesiology Guidelines Task Force From the Department of Anaesthesia and Intensive Care, Evangelical Hospital Vienna, Vienna, Austria (SAKL), Copenhagen Trial Unit, Centre for Clinical Intervention Research, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark (GI), Department of Anaesthesiology and Critical Care Medicine, Franziskus Hospital Bielefeld, Bielefeld, Germany (NRM), Department of Anaesthesia, Mother and Children’s Section, Juliane Marie Center, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark and Department of Pediatric and Neonatal Intensive Care Service, Geneva University Hospital, Geneva, Switzerland (AA) Correspondence to Sibylle A. Kozek-Langenecker, Department of Anaesthesia and Intensive Care, Evangelical Hospital Vienna, Hans-Sachs-Gasse 10-12, 1180 Vienna, Austria E-mail: [email protected] Published online 27 November 2013
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Editor, We thank Dr Dietrich and colleagues for their comments1 on the European Society of Anaesthesiology Guidelines on the management of severe perioperative bleeding that were recently published in the European Journal of Anaesthesiology.2 We have always been aware that there would be differing points of view and we consider follow-up discussions to be vital for an evolving understanding of the evidence-based approaches available to anaesthesiologists. The grading system used to analyse the existing evidence and developing recommendations, suggestions and statements is pivotal to any set of guidelines, but it is imperative to remember that the numbers representing the level of recommendation do not have the same meaning for each system. In our case, the initial choice of grading system was the Scottish Intercollegiate Guidelines Network (SIGN) grading system. However, as detailed in the Methods section, during the process of developing the guidelines we made the decision to switch to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system, and specifically to use the UpToDate system,3 the details of which are presented in Table 1 of the guidelines.2 Our rationale was to align with the many other scientic organisations who also favour the GRADE system (including American College of Chest Physicians, Scandinavian Society of Anaesthesiology and Intensive Care Medicine, Society of Critical Care Medicine, Society for Vascular Surgery and European Society of Thoracic Surgeons).4 Thoughtful application of this grading system led to the development of 91 strong recommendations and 81 weak recommendations/suggestions (we note that these figures differ from those calculated by Dietrich et al.1 in Figure 1 of their letter). Dietrich et al.1 note that the recommendations with GRADE >1B should be analysed with caution. We would like to point out that the number 1 in the GRADE system defines recommendation strength, whereas number 1, for example in the SIGN system, defines the level of evidence. Second, we believe that clinicians should be cautious when applying any of the recommendations, suggestions or statements from guidelines to daily practice and should be familiar with, and critical towards, the evidence evaluation criteria of the guideline in question. The GRADE system provides a transparent basis for both defining and interpreting recommendations; it includes elements that are objective and reproducible (i.e. assessment of the quality of the evidence) and elements that will often be subjective and dependent upon circumstances (i.e. deciding on the strength of recommendations), which depend on the balance of desirable and undesirable outcomes and judgement about the patients’ values and preferences. The goal is to enable readers of guidelines to benefit from the systematic analysis of evidence and then to apply that information to their own situation, using their own judgement as necessary.
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As noted by Dietrich et al.,1 many of our assessments of the quality of the evidence were weak. We stress that this does not mean that the included studies were all of low quality. Rather, that when considering all of the relevant evidence, we had limited confidence in what effect the intervention had on the outcomes that we deemed important. This assessment involved evaluating risk of bias, imprecision, inconsistency and indirectness. In many cases, the fact that the quality of the body of evidence was low meant that associated recommendations were graded as weak. In these cases, we made suggestions rather than recommendations. In others, we decided to grade the recommendations as strong despite the lack of strong evidence. Either way, we believe that it is imperative to provide guidance in form of recommendations or suggestions for physicians in treating severe bleeding based on the best evidence that is currently available. By quoting both the assessment of the quality of the body of evidence and the strength of the recommendation, and understanding what these assessments mean, the reader should be able to appreciate what part is our judgement and what part is objective assessment of the quality of evidence. Dietrich et al. address the use of algorithms for the treatment of intraoperative bleeding. The evidence for the 1B recommendation (which we point out is not 1C, as stated by Dietrich et al.) to use transfusion algorithms incorporating predefined intervention triggers to guide haemostatic intervention during intraoperative bleeding is presented in chapter 5.2 However, the guidelines include a further 1C recommendation for the use of point-of-care testing, specifically in the setting of cardiac surgery, supporting evidence for which is also presented in chapter 5.2 This recommendation was broadly based on studies that used an approach of administering haemostatic therapy guided by algorithms, according to pointof-care test results; therefore, the evidence presented supports the use of these variables in combination. Studies capable of separating the impact of the haemostatic treatment algorithm from that of point-of-care monitoring might be interesting, though it is ultimately only haemostatic treatments themselves that can control bleeding. Furthermore, although we agree that further studies are needed to better define the benefit of using point-of-care devices, we find the reference to platelet function testing in intraoperative algorithms puzzling because our panel of experts only assigned a 2C suggestion for the preoperative use of platelet function testing. With regard to the recommendations on the use of fibrinogen concentrate as first-line therapy in cardiac surgery, we agree that the best supporting evidence available to date is the randomised controlled study by Rahe-Meyer et al.,5 despite that only 29 patients received fibrinogen concentrate. However, a large amount of lower quality but consistent evidence also contributes to a compelling evidence base. Many patients have been
treated with fibrinogen concentrate, including those listed in two systematic reviews,6,7 which are cited in the guidelines and support the efficacy of fibrinogen concentrate in cardiac surgery across multiple endpoints. One review alone cited 21 trials, three of which were prospective studies. Together, we feel that these data, including the well designed, randomised controlled trial by Rahe-Meyer et al.,5 support the 1B recommendation that fibrinogen concentrate infusion guided by point-ofcare viscoelastic coagulation monitoring should be used to reduce perioperative blood loss in complex cardiovascular surgery. It will of course be necessary to revisit, and if appropriate, revise this and all other statements and recommendations in the guidelines when new data become available. We express concern with regard to the statement of Dietrich and colleagues on an assumedly recommended target of 22 mm maximum clot firmness (MCF) in the thromboelastometric FIBTEM test following cardiac surgery. This value is only mentioned in a single instance and is only discussed because it features in clinical studies that form supporting evidence; we have not made any recommendations or suggestions for a target FIBTEM MCF. Consequently, the 2C recommendation for an initial dose of 25 to 50 mg kg1 fibrinogen concentrate does not refer to achieving a FIBTEM MCF target of 22 mm. Of note, the level of recommendation for dosing of many haemostatic agents mentioned in the guideline, including for example, cryoprecipitate, is 2C. With regard to the recommendation for prophylactic infusion of 2 g fibrinogen concentrate in coronary artery bypass graft (CABG), we point out that our recommendation is not based on the studies by Blome et al.8 and Karlsson et al. (2009)9 as incorrectly detailed by Dietrich et al.1; neither of these studies assessed the effect of prophylactic administration of fibrinogen concentrate. Instead, evidence was provided by results from another randomised controlled study by Karlsson et al. (2010).10 This study provides the only direct evidence to date to support prophylactic administration of fibrinogen concentrate in patients undergoing CABG. However, the published evidence provides only a low level of confidence about what effect this intervention has in this population on the outcomes that we deemed important; therefore, we suggested considering the use of fibrinogen concentrate preoperatively and allocated a grade of 2C.2 We are in agreement with Dietrich et al.1 that despite no clear safety concerns about thromboembolic complications following fibrinogen supplementation, the existing body of literature is not large enough to clearly exclude such potential risk. A 22-year pharmacovigilance study indicates a low thrombogenic potential of fibrinogen concentrate, but additional large studies are required to evaluate the frequency of rare events such as thromboembolism. Thus, our statement regarding
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thromboembolic complications and fibrinogen concentrate was graded evidence level C. It should be noted that the thrombogenic potential of fibrinogen concentrate was reported as low, with 3.48 thromboembolic events per 100 000 infusions11 (by comparison, for recombinant factor VIIa, 24.6 thromboembolic events per 100 000 infusions12 have been reported). It should also be considered that the thrombogenic risks of platelets, therapeutic plasma and cryoprecipitate have not been assessed in long-term pharmacovigilance studies, although they continue to be used as standard of care. Regarding the use of prothrombin complex concentrates (PCC) in the perioperative period of cardiovascular surgery, we made suggestions to be adopted cautiously, and not recommendations. We felt it important to include such statements, despite gaps in the data, because to omit them would be to ignore possibly important advances. In the guidelines, we recommended that ‘goal-directed therapy with coagulation factor concentrates (fibrinogen and/or PCC) may reduce transfusion associated costs in trauma, cardiac surgery and liver transplantation (B)’.2 We agree with Dietrich et al.1 that no study alone has demonstrated the advantage of using PCC and further studies in this area are needed. However, a number of studies have shown the benefit of using PCC, together with fibrinogen concentrate, as part of a successful strategy to reduce transfusion associated costs,13,14 as per our recommendation. We are grateful to Dietrich et al.1 for their valuable input regarding the recommendation on use of erythropoietin (EPO)-stimulating agents to treat anaemia if iron deficiency has been ruled out (2A). There are some conflicting reports regarding the efficacy and safety of EPO in different patient populations and we therefore took a cautious approach. As noted above though, there is a degree of subjectivity in arriving at strengths of recommendations and it is important that the guidelines process provides room for amendments. In retrospect, we agree that the body of evidence largely supports efficacy and is insufficient to conclude that significant safety issues exist. Further safety data on the risk of deep vein thrombosis with EPO treatment would be valuable, but we nonetheless agree that a grade 1 (strong recommendation, likely to apply to most patients) could be considered here. The grading will be revisited in the next update of the guidelines. We believe that in the setting of life-threatening haemorrhage, the best available data must be relied upon to guide best practice evidence-based medicine. The alternative is to continue with a standard of care that may be suboptimal and often relies upon allogeneic blood products despite insufficient evidence of their efficacy and safety. We continue to welcome any suggestions
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for refining our assessments. We also expect the recommendations to evolve as new data become available; an update of the guidelines is planned in 2015.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: SKL received honoraria for lecturing, travel reimbursement and consulting fees within the last 10 years from Baxter, B. Braun, Biotest, Pfizer-BMS, CSL Behring, Fresenius Kabi, Mitsubishi Pharma, Novo Nordisk, Octapharma, TEM International and Verum Diagnostics. NR-M is a member of advisory boards for CSL Behring and MSD, and received unrestricted grants for clinical studies from these companies. AA and GI did not report any conflicts of interest.
References 1
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Dietrich W, Faraoni D, von Heymann C, et al. ESA guidelines on the management of severe perioperative bleeding. Comments on behalf of the Subcommittee on Transfusion and Haemostasis of the European Association of Cardiothoracic Anaesthesiologists. Eur J Anaesthesiol 2014; 31:239–241. Kozek-Langenecker SA, Afshari A, Albaladejo P, et al. Management of severe perioperative bleeding: guidelines from the European Society of Anaesthesiology. Eur J Anaesthesiol 2013; 30:270–382. UpToDate Grading Guide. http://www.uptodate.com/home/grading-guide [Accessed 05 August 2013]. GRADE working group. Organizations that have endorsed or that are using GRADE. http://www.gradeworkinggroup.org/society/index.htm [Accessed 05 August 2013]. Rahe-Meyer N, Solomon C, Hanke A, et al. Effects of fibrinogen concentrate as first-line therapy during major aortic replacement surgery: a randomized, placebo-controlled trial. Anesthesiology 2013; 118:40–50. Kozek-Langenecker S, Sorensen B, Hess JR, Spahn DR. Clinical effectiveness of fresh frozen plasma compared with fibrinogen concentrate: a systematic review. Crit Care 2011; 15:R239. Warmuth M, Mad P, Wild C. Systematic review of the efficacy and safety of fibrinogen concentrate substitution in adults. Acta Anaesthesiol Scand 2012; 56:539–548. Blome M, Isgro F, Kiessling AH, et al. Relationship between factor XIII activity, fibrinogen, haemostasis screening tests and postoperative bleeding in cardiopulmonary bypass surgery. Thromb Haemost 2005; 93:1101– 1107. Karlsson M, Ternstrom L, Hyllner M, et al. Plasma fibrinogen level, bleeding, and transfusion after on-pump coronary artery bypass grafting surgery: a prospective observational study. Transfusion 2008; 48:2152– 2158. Karlsson M, Ternstrom L, Hyllner M, et al. Prophylactic fibrinogen infusion reduces bleeding after coronary artery bypass surgery. A prospective randomised pilot study. Thromb Haemost 2009; 102:137–144. Dickneite G, Pragst I, Joch C, Bergman GE. Animal model and clinical evidence indicating low thrombogenic potential of fibrinogen concentrate (Haemocomplettan P). Blood Coagul Fibrinolysis 2009; 20:535–540. Aledort LM. Comparative thrombotic event incidence after infusion of recombinant factor VIIa versus factor VIII inhibitor bypass activity. J Thromb Haemost 2004; 2:1700–1708. Spalding GJ, Hartrumpf M, Sierig T, et al. Cost reduction of perioperative coagulation management in cardiac surgery: value of ‘bedside’ thrombelastography (ROTEM). Eur J Cardiothorac Surg 2007; 31:1052–1057. Gorlinger K, Dirkmann D, Hanke AA, et al. First-line therapy with coagulation factor concentrates combined with point-of-care coagulation testing is associated with decreased allogeneic blood transfusion in cardiovascular surgery: a retrospective, single-center cohort study. Anesthesiology 2011; 115:1179–1191. DOI:10.1097/EJA.0000000000000029
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244 Correspondence
Pneumothorax following ultrasound-guided interscalene block Association or complication? Neil MacLennan and Chris Nixon From the Department of Anaesthesia and Perioperative Medicine, Auckland City Hospital, Auckland, New Zealand
abnormality? Is it possible that the pneumothorax was spontaneous, or due to surgery?
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: none.
Correspondence to Dr Chris Nixon, MB, ChB, FRCA, FANZCA, Department of Anaesthesia and Perioperative Medicine, Level 8, Clinical Support Building, Auckland City Hospital, Park Road, Auckland 1023, New Zealand Tel: +64 9 307 4949x25690; fax: +64 9 307 2807; e-mail: [email protected] Published online 20 November 2013
Comment from the editor: Dr Montoro and colleagues did not wish to respond to this letter.
References 1
Editor, 2
We were intrigued by the case described by Montoro et al.1 concerning the appearance of a pneumothorax following an interscalene block. The authors describe the performance of an ultrasound-guided posterolateral approach to the brachial plexus with C5 nerve stimulation. A number of questions remain. If the nerve root was contacted, then the approach would need to be high in the neck and would be well above the dome of the pleura. With the described approach, the C5 and C6 roots are rarely more than 1 to 1.5 cm deep, the needle entering the neck and passing through skin into the scalenus medius muscle, and then directed to the roots in the interscalene groove. If needle imaging was imperfect, resulting in the needle mistakenly being passed too deep, it would pass into the scalenus anterior muscle. If the block was performed in the lower neck, the needle would be directed not at the C5 root but at the superior trunk, but even at this level, the muscular relationships remain and the dome of the pleura would be posterior to scalenus medius. The incidence of pneumothorax reported by Borgeat et al. following nerve stimulation-guided interscalene block does not describe the authors’ needle direction. Borgeat2,3 described the lateral modified approach with a cranialcaudal needle angle of 45 to 608 and needle entry point 0.5 cm below the cricoid cartilage. The reference by Bhatia et al.4 relates to supraclavicular brachial plexus block. The authors’ comments on the loss of needle tip visualisation are well recognised. During the performance of in-plane ultrasound-guided blocks, the focus should remain on the shape of the needle tip. In this regard, the Tuohy needle has advantages as the Huber tip profile is easily identified. A problem highlighted by Gray and Schafhalter-Zoppoth5 is the flexibility of small gauge needles as used in this case, which may bend away from the ultrasound beam rendering them more difficult to image. The report describes an association of a procedure with an outcome, but there is no certainty that the two are related. Did the patient have a short neck or anatomical
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Montoro E, Ferre F, Yonis H, et al. Pneumothorax as a complication of ultrasound guided interscalene block for shoulder surgery. Eur J Anaesthesiol 2013; 30:90–91. Borgeat A, Ekatodramis G. Anaesthesia for shoulder surgery. Best Prac Res Clin Anaesthesiol 2002; 16:211–225. Borgeat A, Dullenkopf A, Ekatodramis G, Nagy L. Evaluation of the lateral modified approach for continuous interscalene block after shoulder surgery. Anesthesiology 2003; 99:436–442. Bhatia A, Lai J, Chan VW, Brull R. Case report: pneumothorax as a complication of the ultrasound guided supraclavicular approach for brachial plexus block. Anesth Analg 2010; 111:817–819. Gray AT, Schafhalter-Zoppoth I. A concerning direction. Anesthesiology 2004; 100:1325. DOI:10.1097/EJA.0000000000000021
Comparing performance of different laryngoscope blades Shi-Yu Wang, Fu-Shan Xue, Yi Cheng and Xin-Long Cui From the Department of Anaesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China Correspondence to Professor Fu-Shan Xue, Department of Anaesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 33 Ba-Da-Chu Road, Shi-Jing-Shan District, Beijing 100144, People’s Republic of China Tel: +86 13911177655; fax: +86 10 88772106; e-mail: [email protected] Published online 27 November 2013
Editor, In a randomised clinical study, Bule´on et al.1 showed that the Heine XP plastic single-use blade resulted in an increase in the intubation failure rate and a worse laryngeal view compared with the Heine metallic reusable blade and the Callisto metallic single-use blade. The power of this study is its use of a large sample, and the authors have controlled some factors that can significantly affect the laryngeal visualisation and tracheal intubation, such as patient’s characteristics and upper airway anatomy, blade sizes and use of anaesthetic and neuromuscular blocking drugs.2,3 Additionally, the authors openly discuss the limitations of their work. However, we note other issues of this study making interpretation of their results questionable. First, in the method section, the authors stated that the position of the patients’ head and neck during direct
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laryngoscopy was recorded after intubation. In the results section, these data are not provided and compared. Proper positioning of the head and neck (for example, sniffing position) is essential for optimal laryngeal visualisation during direct laryngoscopy and inadequate positioning may result in prolonged or failed tracheal intubation attempts because of the inability to visualise the larynx.4 Moreover, we do not feel that the authors clearly described whether they had achieved an optimal attempt at laryngoscopy when evaluating the laryngoscopic views obtained with the three blades.
blade groups. In clinical practice, intubation difficulty with IDS scores 1 to 5 should not be a problem for experienced anaesthesiologists. Adnet et al.10 demonstrated that when IDS was 5 or less, intubation time did not vary significantly. When IDS was more than 5, however, intubation time increased rapidly in relation to the score.10 As a result, an IDS score of more than 5 is often defined as difficult intubation and used as the primary outcome of a comparative study.8,11 In the study by Bule´on et al.,1 the incidence of an IDS score of more than 5 did not significantly differ between the study groups.
Second, there was no mention of how many experienced anaesthesiology nurses or physicians participated in this study. Metallic reusable blades are devices that are frequently used for tracheal intubation. There are many single-use blades on the market and these differ greatly in their main characteristics, such as configuration, quality and robustness.5–8 Unfortunately, the authors did not explain whether there were significant differences in shape, length, angulation, rigidity, light intensity and brightness field among the three blades that were tested in their study. More importantly, it remained unclear whether all participants had used the plastic and metallic single-use blades in routine tracheal intubation before this study. Differently shaped blades may require different laryngoscopic techniques and may even result in difficulty in laryngoscopy and tracheal intubation performed by a novice user.5,8 Thus, we cannot exclude the possibility that different experiences and proficiency levels of participants with the three blades tested in this study attribute to the findings. Here, we would like to share the viewpoint of Behringer et al.9 that in a comparative intubation study, for the results to be valid, participants must be equally proficient with each tested device in order to avoid bias.
Finally, apart from the blade types, interaction of many other factors can also affect the ease of laryngoscopy and success rate of tracheal intubation.3,4 Thus, we feel that the study by Bule´on et al.1 does not provide highlevel evidence to support the conclusion that the plastic single-use blade is less efficient than the metallic reusable and single-use blades.
Third, sample size was selected to detect a difference of 3% in the rate of intubation failure between the metallic reusable and the single-use blade groups and the plastic single-use blade group. However, of 1863 eligible patients, 190 (10.2%) were excluded from the final analysis because of missing data. The authors did not explain whether these excluded patients were equally distributed among the three study groups. A significantly higher rate of missing data in any group may have biased the final analysis of the results. Fourth, the intubation difficulty scale (IDS) is the sum of the seven parameters associated with the intubation effort. An IDS score 1 to 5 indicates slight intubation difficulty and an IDS score more than 5 indicates moderate to major intubation difficulty.10 In this study, a notably higher IDS score in the plastic single-use blade group was mainly due to a higher number of patients with IDS scores 1 to 5 in the plastic single-use blade group compared with the metallic reusable and single-use
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: none. Comment from the editor: Dr Bule´on and colleagues did not wish to respond to this letter.
References 1
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Bule´on C, Parienti JJ, Lesage A, et al. Comparison of plastic and metallic single-use and metallic reusable laryngoscope blades: a randomised controlled trial. Eur J Anaesthesiol 2013; 30:163–169. Benumof JL. Difficult laryngoscopy. Obtaining the best view. Can J Anesth 1994; 41:361–365. Hagberg CA, Benumof JL. The American Society of Anesthesiologists’ management of difficult airway algorithm and explanation-analysis of the algorithm. In: Hagberg CA, editor. Benumof’ airway management, 2nd ed St Louis, MO: Mosby-Year Book Inc; 2007. pp. 245–248. El-Orbany M, Woehlck H, Salem MR. Head and neck position for direct laryngoscopy. Anesth Analg 2011; 113:103–109. Rassam S, Wilkes AR, Hall JE, Mecklenburgh JS. A comparison of 20 laryngoscope blades using an intubating manikin: visual analogue scores and forces exerted during laryngoscopy. Anaesthesia 2005; 60:384–394. Galinski M, Catineau J, Rayeh F, et al. Laryngoscope plastic blades in scheduled general anesthesia patients: a comparative randomized study. J Clin Anesth 2011; 23:107–112. Amour J, Le Manach YL, Borel M, et al. Comparison of single-use and reusable metal laryngoscope blades for orotracheal intubation during rapid sequence induction of anesthesia: a multicenter cluster randomized study. Anesthesiology 2010; 112:325–332. Jabre P, Galinski M, Ricard-Hibon A, et al. Out-of-hospital tracheal intubation with single-use versus reusable metal laryngoscope blades: a multicenter randomized controlled trial. Ann Emerg Med 2011; 57:225–231. Behringer EC, Cooper RM, Luney S, Osborn IP. The comparative study of video laryngoscopes to the Macintosh laryngoscope: defining proficiency is critical. Eur J Anaesthesiol 2012; 29:158–159. Adnet F, Borron SW, Racine SX, et al. The intubation difficulty scale (IDS): proposal and evaluation of a new score characterizing the complexity of endotracheal intubation. Anesthesiology 1997; 87:1290– 1297. Galinski M, Adnet F, Tran D, et al. Disposable laryngoscope blades do not interfere with ease of intubation in scheduled general anaesthesia patients. Eur J Anaesthesiol 2003; 20:731–735. DOI:10.1097/EJA.0000000000000020
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CORRESPONDENCE Accidental intra-arterial injection of paracetamol Different preparations, different results Sukhen Samanta, Nilanchal Chakraborty and Sujay Samanta From the Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India Correspondence to Dr Sukhen Samanta, Sanjay Gandhi Postgraduate Institute of Medical Sciences, New PG Hostel, Room No. 218, Lucknow 226014, India Tel: +91 08 00 496 7745; e-mail: [email protected] Published online 27 June 2013
Editor, Accidental intra-arterial injections of some anaesthetic drugs may cause arterial spasm with negative consequences.1 Similarly, there are drugs which are given unintentionally or intentionally without such consequences.2 For obvious reasons, controlled trials that may elucidate the pathophysiology underlying arterial spasm after intra-arterial injection cannot be performed.2 We report two cases of unintentional intra-arterial injection of different preparations of paracetamol with different outcomes. As far as we know, adverse outcome after intra-arterial injection of paracetamol has not been reported so far. The patient (case 1) and the patient’s father (case 2) reviewed the case reports and gave written permission for publication. A 42-year-old man was scheduled for laparoscopic cholecystectomy. At the end of surgery, he was accidentally given a benzyl alcohol-based preparation of paracetamol 900 mg intra-arterially for postoperative pain relief. Following recovery from anaesthesia, he complained about pain in his right hand. The search for the cause of that pain revealed the unintentional paracetamol injection through an extension line attached to a catheter in the right radial artery. Bluish discolouration was noted on two fingers in the radial artery distribution 40 min after the injection. Treatment was initiated with intra-arterial heparin 5000 IU and intravenous lidocaine 60 mg. Despite this, gangrene developed. Three days after the accidental intra-articular injection, he had to undergo amputation of the distal part of his affected fingers, although, on radiological examination, the brachial arterial cross-section area and flow was normal (Fig. 1). A 7-year-old boy (bodyweight 22 kg) was scheduled for a craniotomy for medulloblastoma. Accidentally, an aqueous-based preparation of paracetamol 350 mg (Perfalgan 10 mg ml1) was given into a radial artery in
the postoperative period. The patient stayed asymptomatic; the incidence was only identified during the routine postoperative round. Doppler sonography revealed normal radial arterial pulse waves after a 7-day follow-up. The paracetamol preparations had a similar pH. Previously, drugs dissolved in mannitol (for instance vecuronium) had been used safely by the intra-arterial route.3 We assume that in the first case, the benzyl alcohol preservative that was used in the nonaqueous preparation of paracetamol may have caused the vasospasm, leading to endothelial oedema and capillary endothelial dysfunction.4 Complications of intra-arterial injection of nonaqueous agents (phenytoin, propofol)5 and highly alkaline drugs (thiopentone)1 have been known for years. On the contrary, drugs like atropine, pancuronium or fentanyl have been injected intra-arterially without untoward effects.5 Membrane-soluble drugs are known to cause more complications.4 Multiple theories have been postulated to explain the arterial spasm, or hypoperfusion which is the final common pathway for limb ischaemia. Unintentional (iatrogenic or accidental) intra-arterial injections may occur in the early postoperative period when patients are recovering from anaesthesia. In our first case, the dramatic outcome was due to benzyl alcohol preservative but not the paracetamol itself. Consequently, drugs containing benzyl alcohol must not be injected intra-arterially. Finally, every country should have a strict drug control system that prevents inappropriate mixing of drugs and preservatives, and that stops ‘home made’ practices Fig. 1
Hand showing gangrene along the radial artery distribution.
0265-0215 ß 2014 Copyright European Society of Anaesthesiology
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to ensure patient safety. Although the intra-articular administration of an aqueous-based preparation of paracetamol did not cause any harm, the intra-arterial injection of any paracetamol solution should be prevented.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: none.
References 1 2
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Stone HH, Donnelly CC. The accidental intra-arterial injection of thiopental. Anesthesiology 1961; 22:995–1006. Ghouri AF, Mading W, Prabaker K. Accidental intraarterial drug injection via intravascular catheters placed on the dorsum of the hand. Anesth Analg 2002; 95:487–491. Lee JY, Choi JH, Yoon JH. Accidental intra-arterial injection of vecuronium: a case report. Korean J Anesthesiol 2004; 47:917–919. Knill RL, Evans D. Pathogenesis of gangrene following intra-arterial injection of drugs: a new hypothesis. Can Anaesth Soc J 1975; 22:637–646. Fikkers BG, Wuis EW, Wijnen MH, Scheffer GJ. Intra-arterial injection of anesthetic drugs. Anesth Analg 2006; 103:792–794. DOI:10.1097/EJA.0b013e328363163c
Anaesthesiological support in a cardiac electrophysiology laboratory Aaron Conway From the Institute of Health & Biomedical Innovation, Brisbane, Queensland, Australia Correspondence to Dr Aaron Conway, Institute of Health & Biomedical Innovation, Queensland University of Technology, Level 7, 60 Musk Ave, Kelvin Grove, Brisbane, QLD 4064, Australia Tel: +61 7 3138 6124; e-mail: [email protected] Published online 23 November 2013
Editor, I read with great interest the article by Trouve-Buisson et al.1 that was recently published in the European Journal of Anaesthesiology describing the anaesthetic management during implantation of cardiovascular implantable electronic devices (CIEDs). The authors noted that their results presented new evidence in the recent debate about sedation by nonanaesthesiologists and went on to state that as severe complications represented almost one-third of the overall complication rate, direct supervision by a nurse anaesthetist or anaesthesiologist seems to be required. As the debate is in regard to sedation by nonanaesthesiologists not general anaesthetic by nonanaesthesiologists, the statistic presented to support the authors’ argument is misleading.2 It was reported that 26% (n ¼ 63) of the patients who received deep sedation had at least one complication and 4% (n ¼ 10)
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experienced a severe complication. Therefore, of the 63 deeply sedated patients who had a complication, in only 16% (n ¼ 10) of patients was it severe. In contrast, 71% (n ¼ 15) of general anaesthetic patients had a complication and of these patients, in 11 (73%) the complication was severe. On the basis of the drastically disparate complication rates between patients who received general anaesthesia and those who received deep sedation, it does not seem reasonable for the same conclusion to be drawn for both groups of patients. Also, considering the authors noted that their study presented new evidence in the recent debate about sedation by nonanaesthesiologists, it is surprising that the complication rate of the patients who received deep sedation with propofol in this study was not considered in relation to a recent similar study, which involved the administration of propofol by nonanaesthesiologists.3 Sayfo et al.3 reported the frequency of adverse events during proceduralist-directed nurse-administered propofol sedation (PDNAPS) during the implantation of cardiac implantable electronic devices. Interestingly, a higher incidence of both mild (38.7%) and severe complications (10%) was reported in this study.1,3 Potentially then, administration of propofol for deep sedation during the implantation of cardiac implantable electronic devices by anaesthesiologists (or nurse anaesthetists) may actually be associated with decreased risk of complications. Therefore, an adequately powered randomised controlled trial would be required to draw strong conclusions for or against the use of PDNAPS during the implantation of cardiac implantable electronic devices. Yet, the authors noted that on the basis of their findings, such a trial may be unethical. It should be noted that recent surveys of sedation practice in the United States of America and also Australia and New Zealand indicated that PDNAPS is actually already being utilised in practice.4,5 Furthermore, gaining access to monitored anaesthesia care for sedation in the cardiac catheterisation laboratory is difficult in many institutions around the world.4,5 Moreover, the need for more effective sedative and analgesic medications for cardiovascular procedures than the typical benzodiazepine and opioids combination that can be safely administered without an anaesthetist present has been recently observed and is also the subject of numerous recent investigations.3,6,7 For these reasons, in contrast to the authors’ opinion that trials comparing nonanaesthesiologist with anaesthesiologist managed sedation may be unethical, the evidence at hand indicates that such trials are indeed required.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: none.
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238 Correspondence
References 1
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Trouve-Buisson T, Arvieux L, Bedague D, et al. Anaesthesiological support in a cardiac electrophysiology laboratory: a single-centre, prospective observational study. Eur J Anaesthesiol 2013; 30:1–6. Conway AW, Page K, Rolley JX, Worrall-Carter L. Nurseadministered procedural sedation and analgesia in the cardiac catheter laboratory: an integrative review. Int J Nurs Studies 2011; 48:1012–1023. Sayfo S, Vakil KP, Alqaqa’a A, et al. A retrospective analysis of proceduralist-directed, nurse-administered propofol sedation for implantable cardioverter-defibrillator procedures. Heart Rhythm 2012; 9:342–346. Conway A, Rolley JX, Page K, Fulbrook P. Trends in nurse-administered procedural sedation and analgesia across Australian and New Zealand cardiac catheterisation laboratories: results of an electronic survey. Aust Crit Care 2013. DOI:10.1016/j.aucc.2013.05.003. Gaitan BD, Trentman TL, Fassett SL, et al. Sedation and analgesia in the cardiac electrophysiology laboratory: a national survey of electrophysiologists investigating the who, how, and why? J Cardiothor Vasc Anesth 2011; 25:647–659. Conway A, Rolley JX, Fulbrook P, Page K. Issues and challenges associated with nurse-administered procedural sedation and analgesia in the cardiac catheterisation laboratory: a qualitative study. J Clin Nurs 2013; [Epub ahead of print]. DOI:10.1111/jocn.12147. Dupanovic´ M, Lakkireddy D, Emert MP, Krebill R. Utility of dexmedetomidine in sedation for radiofrequency ablation of atrial fibrillation. J Perianesth Nurs 2013; 28:144–150. DOI:10.1097/EJA.0000000000000032
Reply to: anaesthesiological support in a cardiac electrophysiology laboratory Thibaut Trouve´-Buisson and Pierre Albaladejo From the Department of Anaesthesia and Intensive Care Medicine, Grenoble University Hospital, La Tronche, Ise`re, France Correspondence to Trouve´-Buisson, MD, Department of Anaesthesia and Intensive Care Medicine, Grenoble University Hospital, 38700 La Tronche, Ise`re, France Tel: +334 7676 9288; e-mail: [email protected] Published online 27 November 2013
did not specifically analyse the subgroup of patients undergoing general anaesthetic. Moreover, we are clearly inclined to think that the choice of the anaesthetic procedure is part of the anaesthetic care. To our knowledge, there is no efficient system described in the literature to direct safely ‘low-risk’ patients to nonanaesthetic care and ‘high-risk’ patients to an anaesthetist. Finally, we believe that even the subgroup of deeply sedated patients with its overall complication rate of 26% and severe complication rate of 4% must receive anaesthetic attention. Second, concerning the remark of Dr Conway that randomised controlled trials are needed, we would argue that it will be difficult to design such a study comparing two systems: anaesthesia care by trained staff (nurse anaesthetist and anaesthesiologist) with a specific training for propofol administration by nurses or cardiologists. In the second one, a failure in the training process or an unusual complication would imply the intervention of an anaesthesiologist or intensivist. Third, comparing this cohort with other studies seemed difficult because of different definitions of severe complications, study designs and sedation protocols (particularly propofol-associated drugs)2,3 or differences in the procedures requiring sedation.4 Our cohort included only patients requiring cardiovascular implantable electronic devices management and excluded radiofrequency catheter ablation. Finally, we do agree with Dr Conway that more research on this specific and very fragile population is necessary to eventually improve perioperative care.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none.
Editor,
Conflicts of interest: none.
We are grateful to Dr Conway for his thoughtful comments1 concerning our recently published study,2 and we are happy to provide the following answers to the issues that he has raised.
References
First, the relationship between general anaesthesia and complications cannot be easily interpreted in this cohort. General anaesthesia was often performed because of a particular risk of complications, mostly procedural (such as probe extraction), requiring complete immobility and/or at risk of the need for a rescue procedure. The aim of this cohort was to describe the complications rate and risk factors for the overall population admitted to our cardiac electrophysiology laboratory and thus we
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Conway A. Anaesthesiological support in a cardiac electrophysiology laboratory. Eur J Anaesthesiol 2014; 31:237–238. Trouve´-Buisson T, Arvieux L, Bedague D, et al. Anaesthesiological support in a cardiac electrophysiology laboratory: a single-centre, prospective observational study. Eur J Anaesthesiol 2013; 30: 658–663. Sayfo S, Vakil KP, Alqaqa’a A, et al. A retrospective analysis of proceduralist-directed, nurse-administered propofol sedation for implantable cardioverter-defibrillator procedures. Heart Rhythm 2012; 9:342–346. Dupanovic M, Lakkireddy D, Emert MP, Krebill R. Utility of dexmedetomidine in sedation for radiofrequency ablation of atrial fibrillation. J Perianesth Nurs 2013; 28:144–150. DOI:10.1097/EJA.0000000000000030
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Correspondence
ESA guidelines on the management of severe perioperative bleeding Comments on behalf of the Subcommittee on Transfusion and Haemostasis of the European Association of Cardiothoracic Anaesthesiologists Wulf Dietrich, David Faraoni, Christian von Heymann, Daniel Bolliger, Marco Ranucci, Michael Sander and Peter Rosseel From the Institute for Research in Cardiac Anaesthesia, Munich, Germany (WD), Department of Anaesthesiology, Queen Fabiola Children’s University Hospital, Brussels, Belgium (DF), Department of Anaesthesiology and Intensive Care Medicine, Charite´-Universita¨tsmedizin Berlin, Campus Virchow-Klinikum, Berlin, Germany (CvH), University Hospital Basel, Department of Anaesthesia and Intensive Care Medicine, Basel, Switzerland (DB), Department of Cardiothoracic and Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, San Donato Milanese, Milan, Italy (MR), Department of Anaesthesiology and Intensive Care Medicine, Charite´-Universita¨tsmedizin Berlin, Campus Charite´ Mitte, Berlin, Germany (MS), and Department of Anaesthesia and Intensive Care, Amphia Hospital, Breda, The Netherlands (PR) Correspondence to Wulf Dietrich, Institute for Research in Cardiac Anesthesia, Winthirstr. 4, 80639 Munich, Germany Tel: +004989166199; e-mail: [email protected] Published online 27 November 2013
Editor, We read with interest the recent guidelines of the European Society of Anaesthesiology published in the June 2013 issue of the European Journal of Anaesthesiology.1 We congratulate the authors for putting their efforts together with the common aim to review the current literature and to write these recommendations. Indeed, more than 18 general and specific clinical settings were reviewed, leading to about 200 recommendations. However, we believe that for the specific setting of cardiac surgery, some important remarks should be made. The GRADE system used by the authors should be detailed and considered before guidelines can be applied in clinical practice. Indeed, only GRADE 1A and 1B are based on randomised trials in which benefit appears to outweigh risk. GRADE 1C relates to observational or low-quality randomised controlled trials. On the contrary, trials in which the benefit was closely balanced with risk are classified as GRADE 2. Considering this scoring system, all recommendations with GRADE >1B should be interpreted with caution and should not be considered as strong and clinically relevant until further evidence from sufficiently powered studies has been provided. Figure 1 summarises grades of recommendation drawn from the ESA guidelines. We found that the vast majority of the recommendations consisted of low-grade recommendations and therefore should be interpreted with caution. For example, the authors recommended the application of transfusion algorithms incorporating predefined intervention triggers to guide haemostatic therapy during intraoperative bleeding (GRADE 1C). We agree that an algorithm-based approach improves perioperative management of bleeding. However, it is not clear
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whether this benefit is due to the application of the algorithm itself or to the use of point-of-care monitoring (1C). Thus, an algorithm-based approach should be recommended, but further studies are needed to better define the benefit of using point-of-care devices, especially platelet function testing (2C). The authors recommend the administration of fibrinogen concentrates in different clinical settings. Rahe-Meyer et al.2 recently published the only randomised controlled trial that tested a well designed algorithm in cardiac surgery. Even if the results of this study argue that fibrinogen concentrates should be used as a first-line therapy, this study only included 29 patients who were treated with fibrinogen. Furthermore, in the Guidelines, the target fibrinogen level after cardiac surgery is recommended to be a maximum clot firmness of 22 mm in the FIBTEM tracing (p. 288). This target value has been investigated in two small nonrandomised studies including a total of 16 patients in whom a maximum clot firmness of 22 mm was targeted. In the fibrinogen concentrate supplemented patients, reduced blood loss and less transfusion requirements were observed.3,4 Furthermore, the suggested fibrinogen dose is a matter of concern. The authors recommend (2C) the administration of 25 to 50 mg kg1 fibrinogen. However, this arbitrary target level of 22 mm at FIBTEM was only reached in one study,4 with a median fibrinogen dose of 7.8 2.7 g (range, 5 to 13 g). Such high doses require support from sufficiently powered studies. In addition, the recommendation of a prophylactic preoperative infusion of 2 g fibrinogen concentrate in patients with fibrinogen concentration less than 3.8 g l1 comes from a retrospective analysis (N ¼ 98, CABG patients) by Blome et al.5 but could not be confirmed in a larger prospective study (N ¼ 170).6 Preoperative fibrinogen levels between transfused and nontransfused patient were not different, but postoperative fibrinogen levels were associated with blood loss, although this correlation was rather weak (r ¼ 0.53). This is too little evidence to support preoperative fibrinogen supplementation. Finally, we think that the Guidelines should have mentioned that, despite no clear safety concerns about thromboembolic complications of fibrinogen supplementation, the existing body of literature is not large enough to clearly exclude this potential risk. In conclusion, our committee agrees that the administration of fibrinogen concentrate may be associated with reduced blood loss and transfusion requirements in the perioperative period in patients undergoing cardiac surgery, but the dosing scheme, the fibrinogen level to be targeted and outcomes should be better studied in further large, well designed trials. There are at least four randomised trials on fibrinogen supplementation in cardiac surgery currently registered in clinicaltrials.gov, and
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Fig. 1
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Number of recommendations
45
30
15
0 1A
1B
1C
2A
2B
2C
A
B
C
GRADE system Histogram summarising the number of recommendations corresponding to each GRADE cited in the Guidelines.
we suggest waiting for the results of these studies before sound recommendations are made. Almost the same concerns could be applied to the use of prothrombin complex concentrate. No prospective trial has compared the efficacy of prothrombin complex concentrate alone with other therapies in the perioperative period of cardiovascular surgery. Well designed, randomised controlled trials are needed before prothrombin complex concentrate may be recommended. The authors state that ‘goal-directed therapy with coagulation factor concentrates (fibrinogen and/or prothrombin complex concentrate) may reduce transfusion-associated costs in trauma, cardiac surgery and liver transplantation (B)’. Similar to the use of fibrinogen concentrate, EACTA’s Subcommittee of Transfusion and Haemostasis recommends considering these recommendations in clinical practice with extreme caution owing to the small amount of data that are available supporting the use of prothrombin complex concentrate in cardiac surgery. Apart from coagulation, these Guidelines have also addressed perioperative anaemia management. The Guidelines recommend (p. 217) ‘if iron deficiency has been ruled out, we suggest treating anaemic patients with erythropoietin-stimulating agents 2A’. The authors have clearly pointed out that a large body of prospective trials (N ¼ 18), systematic reviews, meta-analyses (N ¼ 3) and guidelines (N ¼ 1) has demonstrated the efficacy of human recombinant erythropoietin. With regard to the
clinical benefit outweighing the risks of erythropoietin treatment, there has been only one study so far that has shown an increased risk of thromboembolism in spinal surgery.7 In this study, thromboprophylaxis was not performed routinely as recommended. According to the GRADE system, the recommendation to treat anaemia should not be 2A, but at least 1B. In general conclusion, the Subcommittee on Transfusion and Haemostasis of EACTA would like to congratulate the European Society of Anaesthesiology for publishing this large review of the literature. However, we would like to draw attention to the fact that some recommendations in these Guidelines are only supported by small, and not always randomised studies. In particularly with respect to the use of coagulation factor concentrates, further prospective trials are needed before high-level recommendations can be made.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: WD: Formerly, consultant for Bayer Corp., Leverkusen, Germany, Consultant for The Medicines Company, Munich-Leipzig, Germany, Consultant for Nordic Pharma SAS, Paris, France. Formerly, study support from CSL Behring, Marburg, Germany. DF: no conflicts of interest. CvH: Within the last 3 years, CvH received speaker and/or consultancy honoraria from Bayer Healthcare, Boehringer Ingelheim, Pfizer GmbH, BMS,
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Correspondence
NovoNordisk Pharma, Nordic Pharma, The Medicines Company, Vifor Pharma and Janssen-Cilag as well as research support by CSL Behring, TEM International, Bayer Healthcare, Boehringer Ingelheim and Baxter. DB: received speaker honorarium from TEM International, Munich, Germany, and an unrestricted research grant from CSL Behring, Berne, Switzerland. MR: Within the last 3 years, MR received speaker and/or consultancy honoraria from NovoNordisk Pharma, The Medicines Company, CSL Behring, Grifols, Roche, Medtronic. DB received speaker honorarium from TEM International, Munich, Germany, and an unrestricted research grant from CSL Behring, Berne, Switzerland. MS: within the last 3 years, MS received research support from The Medicines Company and NovoNordisk Pharma. PR: no conflicts of interest.
References 1
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Kozek-Langenecker SA, Afshari A, Albaladejo P, et al. Management of severe perioperative bleeding: guidelines from the European Society of Anaesthesiology. Eur J Anaesthesiol 2013; 30:270–382. Rahe-Meyer N, Solomon C, Hanke A, et al. Effects of fibrinogen concentrate as first-line therapy during major aortic replacement surgery: a randomized, placebo-controlled trial. Anesthesiology 2013; 118:40–50. Rahe-Meyer N, Pichlmaier M, Haverich A, et al. Bleeding management with fibrinogen concentrate targeting a high-normal plasma fibrinogen level: a pilot study. Br J Anaesth 2009; 102:785–792. Rahe-Meyer N, Solomon C, Winterhalter M, et al. Thromboelastometryguided administration of fibrinogen concentrate for the treatment of excessive intraoperative bleeding in thoracoabdominal aortic aneurysm surgery. J Thorac Cardiovasc Surg 2009; 138:694–702. Blome M, Isgro F, Kiessling AH, et al. Relationship between factor XIII activity, fibrinogen, haemostasis screening tests and postoperative bleeding in cardiopulmonary bypass surgery. Thromb Haemost 2005; 93:1101– 1107. Karlsson M, Ternstrom L, Hyllner M, et al. Plasma fibrinogen level, bleeding, and transfusion after on-pump coronary artery bypass grafting surgery: a prospective observational study. Transfusion 2008; 48:2152– 2158. Stowell CP, Jones SC, Enny C, et al. An open-label, randomized, parallelgroup study of perioperative epoetin alfa versus standard of care for blood conservation in major elective spinal surgery: safety analysis. Spine 2009; 34:2479–2485. DOI:10.1097/EJA.0000000000000033
Reply to: ESA guidelines on the management of severe perioperative bleeding Sibylle A. Kozek-Langenecker, Georgina Imberger, Niels Rahe-Meyer, Arash Afshari, on behalf of the European Society of Anaesthesiology Guidelines Task Force From the Department of Anaesthesia and Intensive Care, Evangelical Hospital Vienna, Vienna, Austria (SAKL), Copenhagen Trial Unit, Centre for Clinical Intervention Research, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark (GI), Department of Anaesthesiology and Critical Care Medicine, Franziskus Hospital Bielefeld, Bielefeld, Germany (NRM), Department of Anaesthesia, Mother and Children’s Section, Juliane Marie Center, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark and Department of Pediatric and Neonatal Intensive Care Service, Geneva University Hospital, Geneva, Switzerland (AA) Correspondence to Sibylle A. Kozek-Langenecker, Department of Anaesthesia and Intensive Care, Evangelical Hospital Vienna, Hans-Sachs-Gasse 10-12, 1180 Vienna, Austria E-mail: [email protected] Published online 27 November 2013
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Editor, We thank Dr Dietrich and colleagues for their comments1 on the European Society of Anaesthesiology Guidelines on the management of severe perioperative bleeding that were recently published in the European Journal of Anaesthesiology.2 We have always been aware that there would be differing points of view and we consider follow-up discussions to be vital for an evolving understanding of the evidence-based approaches available to anaesthesiologists. The grading system used to analyse the existing evidence and developing recommendations, suggestions and statements is pivotal to any set of guidelines, but it is imperative to remember that the numbers representing the level of recommendation do not have the same meaning for each system. In our case, the initial choice of grading system was the Scottish Intercollegiate Guidelines Network (SIGN) grading system. However, as detailed in the Methods section, during the process of developing the guidelines we made the decision to switch to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system, and specifically to use the UpToDate system,3 the details of which are presented in Table 1 of the guidelines.2 Our rationale was to align with the many other scientic organisations who also favour the GRADE system (including American College of Chest Physicians, Scandinavian Society of Anaesthesiology and Intensive Care Medicine, Society of Critical Care Medicine, Society for Vascular Surgery and European Society of Thoracic Surgeons).4 Thoughtful application of this grading system led to the development of 91 strong recommendations and 81 weak recommendations/suggestions (we note that these figures differ from those calculated by Dietrich et al.1 in Figure 1 of their letter). Dietrich et al.1 note that the recommendations with GRADE >1B should be analysed with caution. We would like to point out that the number 1 in the GRADE system defines recommendation strength, whereas number 1, for example in the SIGN system, defines the level of evidence. Second, we believe that clinicians should be cautious when applying any of the recommendations, suggestions or statements from guidelines to daily practice and should be familiar with, and critical towards, the evidence evaluation criteria of the guideline in question. The GRADE system provides a transparent basis for both defining and interpreting recommendations; it includes elements that are objective and reproducible (i.e. assessment of the quality of the evidence) and elements that will often be subjective and dependent upon circumstances (i.e. deciding on the strength of recommendations), which depend on the balance of desirable and undesirable outcomes and judgement about the patients’ values and preferences. The goal is to enable readers of guidelines to benefit from the systematic analysis of evidence and then to apply that information to their own situation, using their own judgement as necessary.
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As noted by Dietrich et al.,1 many of our assessments of the quality of the evidence were weak. We stress that this does not mean that the included studies were all of low quality. Rather, that when considering all of the relevant evidence, we had limited confidence in what effect the intervention had on the outcomes that we deemed important. This assessment involved evaluating risk of bias, imprecision, inconsistency and indirectness. In many cases, the fact that the quality of the body of evidence was low meant that associated recommendations were graded as weak. In these cases, we made suggestions rather than recommendations. In others, we decided to grade the recommendations as strong despite the lack of strong evidence. Either way, we believe that it is imperative to provide guidance in form of recommendations or suggestions for physicians in treating severe bleeding based on the best evidence that is currently available. By quoting both the assessment of the quality of the body of evidence and the strength of the recommendation, and understanding what these assessments mean, the reader should be able to appreciate what part is our judgement and what part is objective assessment of the quality of evidence. Dietrich et al. address the use of algorithms for the treatment of intraoperative bleeding. The evidence for the 1B recommendation (which we point out is not 1C, as stated by Dietrich et al.) to use transfusion algorithms incorporating predefined intervention triggers to guide haemostatic intervention during intraoperative bleeding is presented in chapter 5.2 However, the guidelines include a further 1C recommendation for the use of point-of-care testing, specifically in the setting of cardiac surgery, supporting evidence for which is also presented in chapter 5.2 This recommendation was broadly based on studies that used an approach of administering haemostatic therapy guided by algorithms, according to pointof-care test results; therefore, the evidence presented supports the use of these variables in combination. Studies capable of separating the impact of the haemostatic treatment algorithm from that of point-of-care monitoring might be interesting, though it is ultimately only haemostatic treatments themselves that can control bleeding. Furthermore, although we agree that further studies are needed to better define the benefit of using point-of-care devices, we find the reference to platelet function testing in intraoperative algorithms puzzling because our panel of experts only assigned a 2C suggestion for the preoperative use of platelet function testing. With regard to the recommendations on the use of fibrinogen concentrate as first-line therapy in cardiac surgery, we agree that the best supporting evidence available to date is the randomised controlled study by Rahe-Meyer et al.,5 despite that only 29 patients received fibrinogen concentrate. However, a large amount of lower quality but consistent evidence also contributes to a compelling evidence base. Many patients have been
treated with fibrinogen concentrate, including those listed in two systematic reviews,6,7 which are cited in the guidelines and support the efficacy of fibrinogen concentrate in cardiac surgery across multiple endpoints. One review alone cited 21 trials, three of which were prospective studies. Together, we feel that these data, including the well designed, randomised controlled trial by Rahe-Meyer et al.,5 support the 1B recommendation that fibrinogen concentrate infusion guided by point-ofcare viscoelastic coagulation monitoring should be used to reduce perioperative blood loss in complex cardiovascular surgery. It will of course be necessary to revisit, and if appropriate, revise this and all other statements and recommendations in the guidelines when new data become available. We express concern with regard to the statement of Dietrich and colleagues on an assumedly recommended target of 22 mm maximum clot firmness (MCF) in the thromboelastometric FIBTEM test following cardiac surgery. This value is only mentioned in a single instance and is only discussed because it features in clinical studies that form supporting evidence; we have not made any recommendations or suggestions for a target FIBTEM MCF. Consequently, the 2C recommendation for an initial dose of 25 to 50 mg kg1 fibrinogen concentrate does not refer to achieving a FIBTEM MCF target of 22 mm. Of note, the level of recommendation for dosing of many haemostatic agents mentioned in the guideline, including for example, cryoprecipitate, is 2C. With regard to the recommendation for prophylactic infusion of 2 g fibrinogen concentrate in coronary artery bypass graft (CABG), we point out that our recommendation is not based on the studies by Blome et al.8 and Karlsson et al. (2009)9 as incorrectly detailed by Dietrich et al.1; neither of these studies assessed the effect of prophylactic administration of fibrinogen concentrate. Instead, evidence was provided by results from another randomised controlled study by Karlsson et al. (2010).10 This study provides the only direct evidence to date to support prophylactic administration of fibrinogen concentrate in patients undergoing CABG. However, the published evidence provides only a low level of confidence about what effect this intervention has in this population on the outcomes that we deemed important; therefore, we suggested considering the use of fibrinogen concentrate preoperatively and allocated a grade of 2C.2 We are in agreement with Dietrich et al.1 that despite no clear safety concerns about thromboembolic complications following fibrinogen supplementation, the existing body of literature is not large enough to clearly exclude such potential risk. A 22-year pharmacovigilance study indicates a low thrombogenic potential of fibrinogen concentrate, but additional large studies are required to evaluate the frequency of rare events such as thromboembolism. Thus, our statement regarding
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Correspondence
thromboembolic complications and fibrinogen concentrate was graded evidence level C. It should be noted that the thrombogenic potential of fibrinogen concentrate was reported as low, with 3.48 thromboembolic events per 100 000 infusions11 (by comparison, for recombinant factor VIIa, 24.6 thromboembolic events per 100 000 infusions12 have been reported). It should also be considered that the thrombogenic risks of platelets, therapeutic plasma and cryoprecipitate have not been assessed in long-term pharmacovigilance studies, although they continue to be used as standard of care. Regarding the use of prothrombin complex concentrates (PCC) in the perioperative period of cardiovascular surgery, we made suggestions to be adopted cautiously, and not recommendations. We felt it important to include such statements, despite gaps in the data, because to omit them would be to ignore possibly important advances. In the guidelines, we recommended that ‘goal-directed therapy with coagulation factor concentrates (fibrinogen and/or PCC) may reduce transfusion associated costs in trauma, cardiac surgery and liver transplantation (B)’.2 We agree with Dietrich et al.1 that no study alone has demonstrated the advantage of using PCC and further studies in this area are needed. However, a number of studies have shown the benefit of using PCC, together with fibrinogen concentrate, as part of a successful strategy to reduce transfusion associated costs,13,14 as per our recommendation. We are grateful to Dietrich et al.1 for their valuable input regarding the recommendation on use of erythropoietin (EPO)-stimulating agents to treat anaemia if iron deficiency has been ruled out (2A). There are some conflicting reports regarding the efficacy and safety of EPO in different patient populations and we therefore took a cautious approach. As noted above though, there is a degree of subjectivity in arriving at strengths of recommendations and it is important that the guidelines process provides room for amendments. In retrospect, we agree that the body of evidence largely supports efficacy and is insufficient to conclude that significant safety issues exist. Further safety data on the risk of deep vein thrombosis with EPO treatment would be valuable, but we nonetheless agree that a grade 1 (strong recommendation, likely to apply to most patients) could be considered here. The grading will be revisited in the next update of the guidelines. We believe that in the setting of life-threatening haemorrhage, the best available data must be relied upon to guide best practice evidence-based medicine. The alternative is to continue with a standard of care that may be suboptimal and often relies upon allogeneic blood products despite insufficient evidence of their efficacy and safety. We continue to welcome any suggestions
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for refining our assessments. We also expect the recommendations to evolve as new data become available; an update of the guidelines is planned in 2015.
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: SKL received honoraria for lecturing, travel reimbursement and consulting fees within the last 10 years from Baxter, B. Braun, Biotest, Pfizer-BMS, CSL Behring, Fresenius Kabi, Mitsubishi Pharma, Novo Nordisk, Octapharma, TEM International and Verum Diagnostics. NR-M is a member of advisory boards for CSL Behring and MSD, and received unrestricted grants for clinical studies from these companies. AA and GI did not report any conflicts of interest.
References 1
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Dietrich W, Faraoni D, von Heymann C, et al. ESA guidelines on the management of severe perioperative bleeding. Comments on behalf of the Subcommittee on Transfusion and Haemostasis of the European Association of Cardiothoracic Anaesthesiologists. Eur J Anaesthesiol 2014; 31:239–241. Kozek-Langenecker SA, Afshari A, Albaladejo P, et al. Management of severe perioperative bleeding: guidelines from the European Society of Anaesthesiology. Eur J Anaesthesiol 2013; 30:270–382. UpToDate Grading Guide. http://www.uptodate.com/home/grading-guide [Accessed 05 August 2013]. GRADE working group. Organizations that have endorsed or that are using GRADE. http://www.gradeworkinggroup.org/society/index.htm [Accessed 05 August 2013]. Rahe-Meyer N, Solomon C, Hanke A, et al. Effects of fibrinogen concentrate as first-line therapy during major aortic replacement surgery: a randomized, placebo-controlled trial. Anesthesiology 2013; 118:40–50. Kozek-Langenecker S, Sorensen B, Hess JR, Spahn DR. Clinical effectiveness of fresh frozen plasma compared with fibrinogen concentrate: a systematic review. Crit Care 2011; 15:R239. Warmuth M, Mad P, Wild C. Systematic review of the efficacy and safety of fibrinogen concentrate substitution in adults. Acta Anaesthesiol Scand 2012; 56:539–548. Blome M, Isgro F, Kiessling AH, et al. Relationship between factor XIII activity, fibrinogen, haemostasis screening tests and postoperative bleeding in cardiopulmonary bypass surgery. Thromb Haemost 2005; 93:1101– 1107. Karlsson M, Ternstrom L, Hyllner M, et al. Plasma fibrinogen level, bleeding, and transfusion after on-pump coronary artery bypass grafting surgery: a prospective observational study. Transfusion 2008; 48:2152– 2158. Karlsson M, Ternstrom L, Hyllner M, et al. Prophylactic fibrinogen infusion reduces bleeding after coronary artery bypass surgery. A prospective randomised pilot study. Thromb Haemost 2009; 102:137–144. Dickneite G, Pragst I, Joch C, Bergman GE. Animal model and clinical evidence indicating low thrombogenic potential of fibrinogen concentrate (Haemocomplettan P). Blood Coagul Fibrinolysis 2009; 20:535–540. Aledort LM. Comparative thrombotic event incidence after infusion of recombinant factor VIIa versus factor VIII inhibitor bypass activity. J Thromb Haemost 2004; 2:1700–1708. Spalding GJ, Hartrumpf M, Sierig T, et al. Cost reduction of perioperative coagulation management in cardiac surgery: value of ‘bedside’ thrombelastography (ROTEM). Eur J Cardiothorac Surg 2007; 31:1052–1057. Gorlinger K, Dirkmann D, Hanke AA, et al. First-line therapy with coagulation factor concentrates combined with point-of-care coagulation testing is associated with decreased allogeneic blood transfusion in cardiovascular surgery: a retrospective, single-center cohort study. Anesthesiology 2011; 115:1179–1191. DOI:10.1097/EJA.0000000000000029
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Pneumothorax following ultrasound-guided interscalene block Association or complication? Neil MacLennan and Chris Nixon From the Department of Anaesthesia and Perioperative Medicine, Auckland City Hospital, Auckland, New Zealand
abnormality? Is it possible that the pneumothorax was spontaneous, or due to surgery?
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: none.
Correspondence to Dr Chris Nixon, MB, ChB, FRCA, FANZCA, Department of Anaesthesia and Perioperative Medicine, Level 8, Clinical Support Building, Auckland City Hospital, Park Road, Auckland 1023, New Zealand Tel: +64 9 307 4949x25690; fax: +64 9 307 2807; e-mail: [email protected] Published online 20 November 2013
Comment from the editor: Dr Montoro and colleagues did not wish to respond to this letter.
References 1
Editor, 2
We were intrigued by the case described by Montoro et al.1 concerning the appearance of a pneumothorax following an interscalene block. The authors describe the performance of an ultrasound-guided posterolateral approach to the brachial plexus with C5 nerve stimulation. A number of questions remain. If the nerve root was contacted, then the approach would need to be high in the neck and would be well above the dome of the pleura. With the described approach, the C5 and C6 roots are rarely more than 1 to 1.5 cm deep, the needle entering the neck and passing through skin into the scalenus medius muscle, and then directed to the roots in the interscalene groove. If needle imaging was imperfect, resulting in the needle mistakenly being passed too deep, it would pass into the scalenus anterior muscle. If the block was performed in the lower neck, the needle would be directed not at the C5 root but at the superior trunk, but even at this level, the muscular relationships remain and the dome of the pleura would be posterior to scalenus medius. The incidence of pneumothorax reported by Borgeat et al. following nerve stimulation-guided interscalene block does not describe the authors’ needle direction. Borgeat2,3 described the lateral modified approach with a cranialcaudal needle angle of 45 to 608 and needle entry point 0.5 cm below the cricoid cartilage. The reference by Bhatia et al.4 relates to supraclavicular brachial plexus block. The authors’ comments on the loss of needle tip visualisation are well recognised. During the performance of in-plane ultrasound-guided blocks, the focus should remain on the shape of the needle tip. In this regard, the Tuohy needle has advantages as the Huber tip profile is easily identified. A problem highlighted by Gray and Schafhalter-Zoppoth5 is the flexibility of small gauge needles as used in this case, which may bend away from the ultrasound beam rendering them more difficult to image. The report describes an association of a procedure with an outcome, but there is no certainty that the two are related. Did the patient have a short neck or anatomical
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Montoro E, Ferre F, Yonis H, et al. Pneumothorax as a complication of ultrasound guided interscalene block for shoulder surgery. Eur J Anaesthesiol 2013; 30:90–91. Borgeat A, Ekatodramis G. Anaesthesia for shoulder surgery. Best Prac Res Clin Anaesthesiol 2002; 16:211–225. Borgeat A, Dullenkopf A, Ekatodramis G, Nagy L. Evaluation of the lateral modified approach for continuous interscalene block after shoulder surgery. Anesthesiology 2003; 99:436–442. Bhatia A, Lai J, Chan VW, Brull R. Case report: pneumothorax as a complication of the ultrasound guided supraclavicular approach for brachial plexus block. Anesth Analg 2010; 111:817–819. Gray AT, Schafhalter-Zoppoth I. A concerning direction. Anesthesiology 2004; 100:1325. DOI:10.1097/EJA.0000000000000021
Comparing performance of different laryngoscope blades Shi-Yu Wang, Fu-Shan Xue, Yi Cheng and Xin-Long Cui From the Department of Anaesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China Correspondence to Professor Fu-Shan Xue, Department of Anaesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 33 Ba-Da-Chu Road, Shi-Jing-Shan District, Beijing 100144, People’s Republic of China Tel: +86 13911177655; fax: +86 10 88772106; e-mail: [email protected] Published online 27 November 2013
Editor, In a randomised clinical study, Bule´on et al.1 showed that the Heine XP plastic single-use blade resulted in an increase in the intubation failure rate and a worse laryngeal view compared with the Heine metallic reusable blade and the Callisto metallic single-use blade. The power of this study is its use of a large sample, and the authors have controlled some factors that can significantly affect the laryngeal visualisation and tracheal intubation, such as patient’s characteristics and upper airway anatomy, blade sizes and use of anaesthetic and neuromuscular blocking drugs.2,3 Additionally, the authors openly discuss the limitations of their work. However, we note other issues of this study making interpretation of their results questionable. First, in the method section, the authors stated that the position of the patients’ head and neck during direct
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laryngoscopy was recorded after intubation. In the results section, these data are not provided and compared. Proper positioning of the head and neck (for example, sniffing position) is essential for optimal laryngeal visualisation during direct laryngoscopy and inadequate positioning may result in prolonged or failed tracheal intubation attempts because of the inability to visualise the larynx.4 Moreover, we do not feel that the authors clearly described whether they had achieved an optimal attempt at laryngoscopy when evaluating the laryngoscopic views obtained with the three blades.
blade groups. In clinical practice, intubation difficulty with IDS scores 1 to 5 should not be a problem for experienced anaesthesiologists. Adnet et al.10 demonstrated that when IDS was 5 or less, intubation time did not vary significantly. When IDS was more than 5, however, intubation time increased rapidly in relation to the score.10 As a result, an IDS score of more than 5 is often defined as difficult intubation and used as the primary outcome of a comparative study.8,11 In the study by Bule´on et al.,1 the incidence of an IDS score of more than 5 did not significantly differ between the study groups.
Second, there was no mention of how many experienced anaesthesiology nurses or physicians participated in this study. Metallic reusable blades are devices that are frequently used for tracheal intubation. There are many single-use blades on the market and these differ greatly in their main characteristics, such as configuration, quality and robustness.5–8 Unfortunately, the authors did not explain whether there were significant differences in shape, length, angulation, rigidity, light intensity and brightness field among the three blades that were tested in their study. More importantly, it remained unclear whether all participants had used the plastic and metallic single-use blades in routine tracheal intubation before this study. Differently shaped blades may require different laryngoscopic techniques and may even result in difficulty in laryngoscopy and tracheal intubation performed by a novice user.5,8 Thus, we cannot exclude the possibility that different experiences and proficiency levels of participants with the three blades tested in this study attribute to the findings. Here, we would like to share the viewpoint of Behringer et al.9 that in a comparative intubation study, for the results to be valid, participants must be equally proficient with each tested device in order to avoid bias.
Finally, apart from the blade types, interaction of many other factors can also affect the ease of laryngoscopy and success rate of tracheal intubation.3,4 Thus, we feel that the study by Bule´on et al.1 does not provide highlevel evidence to support the conclusion that the plastic single-use blade is less efficient than the metallic reusable and single-use blades.
Third, sample size was selected to detect a difference of 3% in the rate of intubation failure between the metallic reusable and the single-use blade groups and the plastic single-use blade group. However, of 1863 eligible patients, 190 (10.2%) were excluded from the final analysis because of missing data. The authors did not explain whether these excluded patients were equally distributed among the three study groups. A significantly higher rate of missing data in any group may have biased the final analysis of the results. Fourth, the intubation difficulty scale (IDS) is the sum of the seven parameters associated with the intubation effort. An IDS score 1 to 5 indicates slight intubation difficulty and an IDS score more than 5 indicates moderate to major intubation difficulty.10 In this study, a notably higher IDS score in the plastic single-use blade group was mainly due to a higher number of patients with IDS scores 1 to 5 in the plastic single-use blade group compared with the metallic reusable and single-use
Acknowledgements relating to this article Assistance with the letter: none. Financial support and sponsorship: none. Conflicts of interest: none. Comment from the editor: Dr Bule´on and colleagues did not wish to respond to this letter.
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