ORIGINAL ARTICLE
Transversus abdominis plane (TAP) block after robot-assisted laparoscopic hysterectomy: a randomised clinical trial H. Torup1, M. Bøgeskov1, E. G. Hansen1, C. Palle2, J. Rosenberg3, A. U. Mitchell1, P. L. Petersen4, O. Mathiesen4, J. B. Dahl5 and A. M. Møller1 1
Department of Anaesthesiology, Herlev University Hospital, Copenhagen, Denmark Department of Gynaecology, Herlev University Hospital, Copenhagen, Denmark 3 Department of Surgery, Herlev University Hospital, Copenhagen, Denmark 4 Section of Acute Pain Management, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark 5 Department of Anaesthesiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark 2
Correspondence H. Torup, Department of Anaesthesiology, Herlev University Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark E-mail: [email protected] Conflicts of interest The authors have no conflicts of interest. Funding No external funding declared. None of the authors have competing interests declared. Submitted 10 February 2015; accepted 24 February 2015; submission 31 July 2014. Citation Torup H, Bøgeskov M, Hansen EG, Palle C, Rosenberg J, Mitchell AU, Petersen PL, Mathiesen O, Dahl JB, Møller AM. Transversus abdominis plane (TAP) block after robot-assisted laparoscopic hysterectomy: a randomised clinical trial. Acta Anaesthesiologica Scandinavica 2015; 59: 928– 935 doi: 10.1111/aas.12516
Background: Transversus abdominis plane (TAP) block is widely used as a part of pain management after various abdominal surgeries. We evaluated the effect of TAP block as an add-on to the routine analgesic regimen in patients undergoing robotassisted laparoscopic hysterectomy. Methods: In a prospective blinded study, 70 patients scheduled for elective robot-assisted laparoscopic hysterectomy were randomised to receive either TAP block (ropivacaine 0.5%, 20 ml on each side) or sham block (isotonic saline 0.9%, 20 ml on each side). All patients had patient-controlled analgesia (PCA) with morphine on top of paracetamol and ibuprofen or diclofenac. For the first 24 post-operative hours, we monitored PCA morphine consumption and pain scores with visual analogue scale (VAS) at rest and while coughing. Post-operative nausea and number of vomits (PONV) were recorded. Results: Sixty-five patients completed the study, 34 receiving TAP block with ropivacaine and 31 receiving sham block with isotonic saline. We found no differences in median (interquartile range) morphine consumption the first 24 h between the TAP block group [17.5 mg (6.9–36.0 mg)] and the placebo group [17.5 mg (2.9– 38.0 mg)] (95% confidence interval 10.0–22.6 mg, P = 0.648). No differences were found for VAS scores between the two groups, calculated as area under the curve/1–24 h, neither at rest (P = 0.112) nor while coughing (P = 0.345), or for PONV between groups. Conclusions: In our study, the TAP block combined with paracetamol and Nonsteroidal anti-inflammatory drugs (NSAID) treatment, had no effect on morphine consumption, VAS pain scores, or frequency of nausea and vomiting after robot-assisted laparoscopic hysterectomy compared with paracetamol and NSAID alone.
Editorial comment: what this article tells us
In the present randomised trial, the authors assessed a TAP block as an add-on to the routine analgesic regimen in patients undergoing robot-assisted laparoscopic hysterectomy. Adding bilateral TAP block to paracetamol and ibuoprofen or diclofenac did not result in reduced pain or morphine consumption compared with a sham block. Acta Anaesthesiologica Scandinavica 59 (2015) 928–935
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TAP BLOCK AND LAPAROSCOPIC HYSTERECTOMY
Hysterectomy performed by laparoscopic techniques has been used for 25 years and recently also by a robot-assisted procedure. The robotassisted procedure has been shown to have certain advantages over conventional laparoscopic hysterectomy, as it is associated with reduced length of stay (LOS) and fewer conversions to laparotomy.1 Both conventional laparoscopic hysterectomy and the robot-assisted procedure have a number of advantages over open surgery, as it significantly reduces surgical bleeding as well as pain and the need for analgesics.2 The transversus abdominis plane (TAP) block is increasingly used as pain management after various abdominal surgical procedures.3–7 TAP block after open hysterectomy has shown some reduction in morphine requirement.8 Four studies have evaluated the effect of TAP block after total laparoscopic hysterectomy with varying results.9–12 No studies on TAP block after robotassisted hysterectomy have been published. Our hypothesis was that TAP block would reduce the total need for morphine the first 24 h post-operatively after robot-assisted hysterectomy. The primary goal of our study was to investigate if TAP block as an add-on to the routine analgesic regimen after robot-assisted laparoscopic hysterectomy could reduce the total need for morphine the first 24 h post-operatively. Secondly, we wanted to assess if the TAP block could reduce pain at rest and while coughing, and reduce opioid related side effects such as post-operative nausea and vomiting (PONV).
between 18 and 80 years of age, being able to cooperate and with an American Society of Anesthesiologists class 1–3. We did not include women with known alcohol abuse, daily opioid use within the last 7 days, and known allergy to the local anaesthetic or infection at the injection site. The study took place at the Departments of Anaesthesiology and Gynaecology at Herlev University Hospital, Copenhagen, Denmark, from 9 January 2012 to 23 February 2013.
Methods
Interventions
Patients and design The study was approved from the Regional Ethics Committee (reg. no: H-2–2011-028), the Danish Medicines Agency (EudraCT no: 2011000809-42), and the Danish Data Protection Unit. All participants gave their written informed consent prior to inclusion. The Good Clinical Practice (GCP) Unit at Copenhagen University Hospital monitored the study, and it was registered at http://www.clinicaltrials.gov (NCT01504386). We included women scheduled for robotassisted laparoscopic hysterectomy who met the eligibility criteria. Inclusion criteria were women
Blinding and randomisation The design was a prospective, randomised, placebo-controlled study, blinded both for patients, investigator, and staff involved in data collection, and the study was reported according to the CONSORT (Consolidated Standards of Reporting Trials) guidelines.13 We analysed the data when still blinded for treatment groups, and the codes were not broken until all data analyses were done. We randomised the patients to receive either bilateral TAP block (ropivacaine 0.5%, 20 ml on each side) or placebo block (isotonic saline 0.9%, 20 ml on each side). The regional pharmacy dispensed the active and placebo medications into neutral ampoules identical in appearance, according to a computer-generated randomisation list in blocks of 10. The syringes were pre-packed in sealed boxes labelled with protocol and randomisation numbers. Each patient was assigned to get the medication in the box matching their randomisation number.
Prior to operation, the nurses at the Department of Gynaecology gave all patients paracetamol 1 g and an NSAID (either diclofenac 50 mg or ibuprofen 400 mg; see Table 1) as routine premedication. After induction of anaesthesia, we visualised the TAP with ultrasound scan (LogiQ, GE Healthcare, Buckinghamshire, UK) and placed either a TAP block or placebo block bilaterally, at the level of the umbilicus in the mid-axillary line, using an 80 mm Stimuplex needle (Braun, Melsungen, Germany). To avoid intra-vasal injection, we made a negative aspiration both before injection and after every 5 ml of solution injected. One of four experienced anaesthetists (H. T., E. G. H., M. B., or A. U. M.) placed all TAP blocks, and
Acta Anaesthesiologica Scandinavica 59 (2015) 928–935 ª 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd
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Fig. 1. Study flow diagram. TAP, transversus abdominis plane.
treatment with paracetamol and NSAID may be sufficient. Mild pain (equal to VAS pain below 30 mm) makes it difficult to detect any possible effect of an analgesic technique.19 Three randomised studies and one case-control study have investigated the efficiency of TAP block after conventional laparoscopic hysterectomy.9–12 Our results confirm the findings of the single-blinded study, including only benign laparoscopic hysterectomies,9 as they found neither a reduction in pain scores nor a decrease in opioid consumption as their secondary outcomes.
However, there are many differences between our studies that make it difficult to compare directly, as they used two different laparoscopic techniques and they placed the TAP block after surgery but before emergence. Studies suggest that the TAP block might reduce pain more effectively in the first post-operative hours when placed prior to surgery.20 Their measurements were obtained at 2 and 24 h after surgery, and the perioperative use of pain medication was not reported, which could have influenced the pain scores at 2 h, post-operatively. Acta Anaesthesiologica Scandinavica 59 (2015) 928–935
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error and 20% risk of type 2 error, 28 patients would be needed in each group. To ensure enough patients in case of dropouts, a total of 80 patients were planned for inclusion. For statistical analyses, we used SPSS version 19 (IBM SPSS Statistics; IBM Corporation, Armonk, NY, USA) and described all results as means and standard deviations or median and inter-quartiles as appropriate. Ratio interval and rank scale data were compared with Mann–Whitney’s test between groups. For pain score, the area under the curve (AUC) was estimated and compared with Mann–Whitney’s test between groups. Categorical data were compared with Fisher’s exact test. We chose a 5% significance level for all data. Results We planned to include 80 patients. However, the study was terminated prematurely after 70 included patients due to local restructuring, which made further patient accrual impossible. Of the 70 patients, 65 completed the study – 34 receiving TAP block with ropivacaine (TAP block group) and 31 receiving placebo block with NaCl (placebo group). Reasons for dropouts are given in the CONSORT flowchart (Fig. 1). The two groups were comparable at baseline (Table 1). Because of protocol violation, five patients received oral morphine 20 mg, and 11 patients received i.v. dexamethasone 4 mg as premedication. These patients were randomly distributed between the two groups, and no differences in outcome were found whether they were included or excluded from statistical analyses. We found no differences in total median (interquartile) i.v. morphine consumption the first 24 h post-operatively between the TAP block group [17.5 mg (6.9–36.0 mg)] and the placebo group [17.5 mg (2.9–38.0 mg)] (95% confidence interval 10.0–22.6 mg, P = 0.648). Supplementary morphine given the first hour in the PACU was not different between the two groups (P = 0.467). The median (interquartile) AUC/1–24 h VAS pain while coughing was 20 (11–37) mm in the TAP block group and 21 (6–30) mm in the placebo group (P = 0.345). At rest, the median (interquartile) AUC/1–24 h VAS pain was 12 (3–20) mm in the TAP block group and 7 (1– 19) mm in the placebo group (P = 0.112) (Fig. 2). Post hoc analyses showed that median
(interquartile) VAS pain at rest after first hour was 42 (18–63) mm in TAP block group and 40 (10–52) mm in the placebo group (P = 0.519). VAS pain while coughing after first hour was 43 (14–60) mm in TAP block group and 50 (10– 65) mm in the placebo group (P = 0.903). Distribution of PONV in the two groups is shown in Table 2. No differences in nausea were found between the two groups at any of the observed time points. Number of vomit episodes were not different between the two groups (P = 0.081). No serious adverse events were reported from the two groups. In July 2012, approximately halfway through the inclusions, the Department of Gynaecology changed diclofenac for ibuprofen as standard pain medication for laparoscopic hysterectomy (Table 2). No differences in type of NSAID were found between the two groups (P = 0.805). Discussion Our study is the first to investigate TAP block after robot-assisted laparoscopic hysterectomy. We found that TAP block combined with paracetamol and NSAID treatment had no effect on morphine consumption, VAS pain scores, or frequency of nausea compared with paracetamol and NSAID treatment alone. The robot-assisted technique has possible advantages over traditional laparoscopic hysterectomy, as it is associated with fewer post-operative complications and conversions to laparotomy, as well as it reduces the LOS at the hospital.1 However, in terms of post-operative analgesic use, the two techniques may be comparable.14 NSAIDs have in a multicentre study been shown to reduce morphine requirement and reduce pain (VAS) after open total abdominal hysterectomy.15 Also, NSAIDs are known to have a 30–50% sparing effect on morphine consumption as well as it decreases the side effects of PCA morphine, for example, PONV.16 Our patients reported low median VAS pain scores (25 mm or less) from 2–24 h in both groups – both at rest and while coughing. Other studies have also reported low VAS scores after laparoscopic hysterectomies,17,18 indicating that this procedure may be less painful and to an extent that the basic
Acta Anaesthesiologica Scandinavica 59 (2015) 928–935 ª 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd
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Fig. 1. Study flow diagram. TAP, transversus abdominis plane.
treatment with paracetamol and NSAID may be sufficient. Mild pain (equal to VAS pain below 30 mm) makes it difficult to detect any possible effect of an analgesic technique.19 Three randomised studies and one case-control study have investigated the efficiency of TAP block after conventional laparoscopic hysterectomy.9–12 Our results confirm the findings of the single-blinded study, including only benign laparoscopic hysterectomies,9 as they found neither a reduction in pain scores nor a decrease in opioid consumption as their secondary outcomes.
However, there are many differences between our studies that make it difficult to compare directly, as they used two different laparoscopic techniques and they placed the TAP block after surgery but before emergence. Studies suggest that the TAP block might reduce pain more effectively in the first post-operative hours when placed prior to surgery.20 Their measurements were obtained at 2 and 24 h after surgery, and the perioperative use of pain medication was not reported, which could have influenced the pain scores at 2 h, post-operatively. Acta Anaesthesiologica Scandinavica 59 (2015) 928–935
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Fig. 2. Visual analogue scale (VAS) pain scores at rest and while coughing in the transversus abdominis plane (TAP) block group versus placebo group at 1–24 h post-operatively.
Table 2 Morphine consumption and side effect (PONV) Group TAP block (n = 34) Morphine in 24 h (mg) Morphine first hour in PACU (mg) Patients with vomit episodes (n) Patients receiving ondansetron (n) Patients receiving other antiemetic (n)
17.5 (6.9–35.6) 5 (0–16) 10 21 4 None/mild
Nausea Nausea Nausea Nausea Nausea Nausea
at at at at at at
1 h (n) 2 h (n) 4 h (n) 8 h (n) 18 h (n) 24 h (n)
Group placebo (n = 31)
31 32 28 29 32 31
17.5 (2.9–37.5) 5 (0–10) 16 21 3 Moderate/severe 3 2 6 5 2 3
None/mild
Moderate/severe
26 30 25 27 31 27
4 1 6 4 0 3
All data are given as median and interquartile range, or number. PACU, Post-Anaesthesia Care Unit; PONV, post-operative nausea and vomiting; TAP, transversus abdominis plane.
In a recent published randomised blinded study with almost 200 participants using TAP block with bupivacaine, the authors found no differences in opioid requirements.12 However, they did find a decrease in VAS pain at the time of discharge from 3.8 in the TAP group to 3.1 in the control group, but follow up at 24, 48, and 72 after surgery showed no differences in VAS pain scores between the two groups. This questions the clinical relevance for TAP block after laparoscopic hysterectomy as a basic analgesic regimen may be sufficient in most patients to reduce pain to low levels, where it will be more difficult to show an effect of an add-on treatment as a TAP block.
The double-blinded study10 comparing two different concentrations of ropivacaine (0.5% and 0.25%) with placebo-block (NaCl) found that the 0.5% ropivacaine concentration reduced the mean 24 h opioid consumption from 15 mg to 7.5 mg. No differences were detected between the 0.25% ropivacaine group and placebo-group. The study did not describe where the portholes were placed, and had no results on pain scores between the first and 24 h. However, it is debatable if this rather small reduction in morphine requirement is clinically relevant, as they reported no reduction in morphine related side effects, such as PONV.
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The origin of pain after hysterectomy is believed to come from both somatic and visceral components. The TAP block potentially covers the thoracolumbar nerves (T6-L1) in the abdominal wall and would therefore be effective for pain relief in skin and muscle incisions depending on where the TAP block is placed. In open hysterectomies, TAP block seems to decrease the morphine consumption and the VAS pain scores8 and perhaps adding dexamethasone to the local anaesthetic in the TAP group could be even more effective against pain.21,22 Pain from the skin incisions in open surgery is considerably worse than in laparoscopic surgery, and this might be the reason why TAP block shows more positive results in open hysterectomies compared with the minimal invasive procedures. The TAP block is not believed to cover visceral pain, unless there is a systemic effect by absorption of the local anaesthetics to the systemic circulation.22 This is not well documented for TAP block and should be investigated in the future. Studies have suggested that absorption of the local anaesthetics used in TAP blocks might be greater than in other peripheral blocks, actually with a potential risk of systemic toxicity.;23,24 Future studies are needed to determine the optimal concentrations and volume of the local anaesthetic for an effective TAP block, without risking intoxication of the patient. The strengths of our study is the study design, with a double-blinded, randomised placebo-controlled approach according to GCP and CONSORT guidelines, and the use of PCA with morphine, eliminating the bias of the nurses’ judgement of needed medications. One limitation of our study is that five of the patients received oral morphine 20 mg and 11 patients received dexamethasone 4 mg i.v. prior to surgery, which was a violation to the protocol. However, they were equally spread between the two groups. Another limitation is that the VAS scores were achieved by several different nurses, which could influence the way of asking the patients. We tried to eliminate this bias by educating all involved nurses, had written instructions, and the primary investigator called the nurse in charge 10 min prior to all data collections. Finally, our study was terminated prematurely, and we ended up including less than the 80 patients originally planned, but still more than in the sample size calculation of
2 9 28 patients. However, opioid consumption and pain scores were lower than expected, and inclusion of the actual planned number of patients would have strengthened the results of the study. TAP block is increasingly used worldwide as a supplement for post-operative analgesia after various abdominal surgical procedures. However, the many randomised trials published so far are difficult to compare, as different local anaesthetics, doses, volume, and placement of the TAP blocks are used. Future research is needed to clarify for which procedures TAP block can be recommended. In conclusion, the present study was not able to show that bilateral TAP block on top of a basic analgesic regimen with paracetamol and NSAID could reduce morphine consumption, VAS pain scores, or PONV after robot-assisted laparoscopic hysterectomy.
Acknowledgements The authors want to thank the Department of Anaesthesia, the Post-Operative Care Unit (PACU), and the Department of Gynecology at Herlev University Hospital for their effort to help and support the study. We would also like to thank Smith Medical for providing PCA devices (CADD Solis) for the study. References 1. Scandola M, Grespan L, Vicentini M, Fiorini P. Robot-assisted laparoscopic hysterectomy vs traditional laparoscopic hysterectomy: five metaanalyses. J Minim Invasive Gynecol 2011; 18: 705–15. 2. O’Neill M, Moran PS, Teljeur C, O’Sullivan OE, O’Reilly BA, Hewitt M, Flattery M, Ryan M. Robotassisted hysterectomy compared to open and laparoscopic approaches: systematic review and metaanalysis. Arch Gynecol Obstet 2013; 287: 907–18. 3. Abdallah FW, Chan VW, Brull R. Transversus abdominis plane block: a systematic review. Reg Anesth Pain Med 2012; 37: 193–209. 4. Johns N, O’Neill S, Ventham NT, Barron F, Brady RR, Daniel T. Clinical effectiveness of transversus abdominis plane (TAP) block in abdominal surgery: a systematic review and meta-analysis. Colorectal Dis 2012; 14: e635–642. Acta Anaesthesiologica Scandinavica 59 (2015) 928–935
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5. Mishriky BM, George RB, Habib AS. Transversus abdominis plane block for analgesia after Cesarean delivery: a systematic review and meta-analysis. Can J Anaesth 2012; 59: 766–78. 6. Petersen PL, Mathiesen O, Torup H, Dahl JB. The transversus abdominis plane block: a valuable option for postoperative analgesia? A topical review. Acta Anaesthesiol Scand 2010; 54: 529–35. 7. Charlton S, Cyna AM, Middleton P, Griffiths JD. Perioperative transversus abdominis plane (TAP) blocks for analgesia after abdominal surgery. Cochrane Database Syst Rev 2010; (12): CD007705. 8. Champaneria R, Shah L, Geoghegan J, Gupta JK, Daniels JP. Analgesic effectiveness of transversus abdominis plane blocks after hysterectomy: a metaanalysis. Eur J Obstet Gynecol Reprod Biol 2013; 166: 1–9. 9. Kane SM, Garcia-Tomas V, Alejandro-Rodriguez M, Astley B, Pollard RR. Randomized trial of transversus abdominis plane block at total laparoscopic hysterectomy: effect of regional analgesia on quality of recovery. Am J Obstet Gynecol 2012; 207: 419.e1–5. 10. De. Oliveira GSJ, Milad MP, Fitzgerald P, Rahmani R, McCarthy RJ. Transversus abdominis plane infiltration and quality of recovery after laparoscopic hysterectomy: a randomized controlled trial. Obstet Gynecol 2011; 118: 1230–37. 11. Pather S, Loadsman JA, Gopalan PD, Rao A, Philp S, Carter J. The role of transversus abdominis plane blocks in women undergoing total laparoscopic hysterectomy: a retrospective review. Aust N Z J Obstet Gynaecol 2011; 51: 544–7. 12. Calle GA, Lopez CC, Sanchez E, De Los Rios JF, Vasquez EM, Serna E, Arango AM, Casta~ neda JD, Vasquez RA, Gonz alez A, Escobar A, Almanza LA. Transversus abdominis plane block after ambulatory total laparoscopic hysterectomy: randomized controlled trial. Acta Obstet Gynecol Scand 2014; 93: 345–50. 13. Schulz KF, Altman DG, Moher D. CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials. Trials 2010; 11: 32. 14. Sarlos D, Kots L, Stevanovic N, von Felten S, Schar G. Robotic compared with conventional laparoscopic hysterectomy: a randomized controlled trial. Obstet Gynecol 2012; 120: 604–611. 15. Kroll PB, Meadows L, Rock A, Pavliv L. A multicenter, randomized, double-blind, placebocontrolled trial of intravenous ibuprofen (i.v.-
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ibuprofen) in the management of postoperative pain following abdominal hysterectomy. Pain Pract 2011; 11: 23–32. Marret E, Kurdi O, Zufferey P, Bonnet F. Effects of nonsteroidal antiinflammatory drugs on patientcontrolled analgesia morphine side effects: metaanalysis of randomized controlled trials. Anesthesiology 2005; 102: 1249–60. Ghezzi F, Uccella S, Cromi A, Siesto G, Serati M, Bogani G, Bolis P. Postoperative pain after laparoscopic and vaginal hysterectomy for benign gynecologic disease: a randomized trial. Am J Obstet Gynecol 2010; 203: 118.e1-8. Arden D, Seifert E, Donnellan N, Guido R, Lee T, Mansuria S. Intraperitoneal instillation of bupivacaine for reduction of postoperative pain after laparoscopic hysterectomy: a double-blind randomized controlled trial. J Minim Invasive Gynecol 2013; 20: 620–6. Breivik H, Borchgrevink PC, Allen SM, Rosseland LA, Romundstad L, Hals EK, Kvarstein G, Stubhaug A. Assessment of pain. Br J Anaesth 2008; 101: 17–24. De. Oliveira GSJ, Castro-Alves LJ, Nader A, Kendall MC, McCarthy RJ. Transversus abdominis plane block to ameliorate postoperative pain outcomes after laparoscopic surgery: a meta-analysis of randomized controlled trials. Anesth Analg 2014; 118: 454–63. Ammar AS, Mahmoud KM. Effect of adding dexamethasone to bupivacaine on transversus abdominis plane block for abdominal hysterectomy: a prospective randomized controlled trial. Saudi J Anaesth 2012; 6: 229–33. Koppert W, Weigand M, Neumann F, Sittl R, Schuettler J, Schmelz M, Hering W. Perioperative intravenous lidocaine has preventive effects on postoperative pain and morphine consumption after major abdominal surgery. Anesth Analg 2004; 98: 1050–55, table. Torup H, Mitchell AU, Breindahl T, Hansen EG, Rosenberg J, Moller AM. Potentially toxic concentrations in blood of total ropivacaine after bilateral transversus abdominis plane blocks; a pharmacokinetic study. Eur J Anaesthesiol 2012; 29: 235–38. Griffiths JD, Le NV, Grant S, Bjorksten A, Hebbard P, Royse C. Symptomatic local anaesthetic toxicity and plasma ropivacaine concentrations after transversus abdominis plane block for Caesarean section. Br J Anaesth 2013; 110: 996–1000.
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Transversus abdominis plane (TAP) block after robot-assisted laparoscopic hysterectomy: a randomised clinical trial H. Torup1, M. Bøgeskov1, E. G. Hansen1, C. Palle2, J. Rosenberg3, A. U. Mitchell1, P. L. Petersen4, O. Mathiesen4, J. B. Dahl5 and A. M. Møller1 1
Department of Anaesthesiology, Herlev University Hospital, Copenhagen, Denmark Department of Gynaecology, Herlev University Hospital, Copenhagen, Denmark 3 Department of Surgery, Herlev University Hospital, Copenhagen, Denmark 4 Section of Acute Pain Management, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark 5 Department of Anaesthesiology, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark 2
Correspondence H. Torup, Department of Anaesthesiology, Herlev University Hospital, Herlev Ringvej 75, DK-2730 Herlev, Denmark E-mail: [email protected] Conflicts of interest The authors have no conflicts of interest. Funding No external funding declared. None of the authors have competing interests declared. Submitted 10 February 2015; accepted 24 February 2015; submission 31 July 2014. Citation Torup H, Bøgeskov M, Hansen EG, Palle C, Rosenberg J, Mitchell AU, Petersen PL, Mathiesen O, Dahl JB, Møller AM. Transversus abdominis plane (TAP) block after robot-assisted laparoscopic hysterectomy: a randomised clinical trial. Acta Anaesthesiologica Scandinavica 2015; 59: 928– 935 doi: 10.1111/aas.12516
Background: Transversus abdominis plane (TAP) block is widely used as a part of pain management after various abdominal surgeries. We evaluated the effect of TAP block as an add-on to the routine analgesic regimen in patients undergoing robotassisted laparoscopic hysterectomy. Methods: In a prospective blinded study, 70 patients scheduled for elective robot-assisted laparoscopic hysterectomy were randomised to receive either TAP block (ropivacaine 0.5%, 20 ml on each side) or sham block (isotonic saline 0.9%, 20 ml on each side). All patients had patient-controlled analgesia (PCA) with morphine on top of paracetamol and ibuprofen or diclofenac. For the first 24 post-operative hours, we monitored PCA morphine consumption and pain scores with visual analogue scale (VAS) at rest and while coughing. Post-operative nausea and number of vomits (PONV) were recorded. Results: Sixty-five patients completed the study, 34 receiving TAP block with ropivacaine and 31 receiving sham block with isotonic saline. We found no differences in median (interquartile range) morphine consumption the first 24 h between the TAP block group [17.5 mg (6.9–36.0 mg)] and the placebo group [17.5 mg (2.9– 38.0 mg)] (95% confidence interval 10.0–22.6 mg, P = 0.648). No differences were found for VAS scores between the two groups, calculated as area under the curve/1–24 h, neither at rest (P = 0.112) nor while coughing (P = 0.345), or for PONV between groups. Conclusions: In our study, the TAP block combined with paracetamol and Nonsteroidal anti-inflammatory drugs (NSAID) treatment, had no effect on morphine consumption, VAS pain scores, or frequency of nausea and vomiting after robot-assisted laparoscopic hysterectomy compared with paracetamol and NSAID alone.
Editorial comment: what this article tells us
In the present randomised trial, the authors assessed a TAP block as an add-on to the routine analgesic regimen in patients undergoing robot-assisted laparoscopic hysterectomy. Adding bilateral TAP block to paracetamol and ibuoprofen or diclofenac did not result in reduced pain or morphine consumption compared with a sham block. Acta Anaesthesiologica Scandinavica 59 (2015) 928–935
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ª 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd
TAP BLOCK AND LAPAROSCOPIC HYSTERECTOMY
Hysterectomy performed by laparoscopic techniques has been used for 25 years and recently also by a robot-assisted procedure. The robotassisted procedure has been shown to have certain advantages over conventional laparoscopic hysterectomy, as it is associated with reduced length of stay (LOS) and fewer conversions to laparotomy.1 Both conventional laparoscopic hysterectomy and the robot-assisted procedure have a number of advantages over open surgery, as it significantly reduces surgical bleeding as well as pain and the need for analgesics.2 The transversus abdominis plane (TAP) block is increasingly used as pain management after various abdominal surgical procedures.3–7 TAP block after open hysterectomy has shown some reduction in morphine requirement.8 Four studies have evaluated the effect of TAP block after total laparoscopic hysterectomy with varying results.9–12 No studies on TAP block after robotassisted hysterectomy have been published. Our hypothesis was that TAP block would reduce the total need for morphine the first 24 h post-operatively after robot-assisted hysterectomy. The primary goal of our study was to investigate if TAP block as an add-on to the routine analgesic regimen after robot-assisted laparoscopic hysterectomy could reduce the total need for morphine the first 24 h post-operatively. Secondly, we wanted to assess if the TAP block could reduce pain at rest and while coughing, and reduce opioid related side effects such as post-operative nausea and vomiting (PONV).
between 18 and 80 years of age, being able to cooperate and with an American Society of Anesthesiologists class 1–3. We did not include women with known alcohol abuse, daily opioid use within the last 7 days, and known allergy to the local anaesthetic or infection at the injection site. The study took place at the Departments of Anaesthesiology and Gynaecology at Herlev University Hospital, Copenhagen, Denmark, from 9 January 2012 to 23 February 2013.
Methods
Interventions
Patients and design The study was approved from the Regional Ethics Committee (reg. no: H-2–2011-028), the Danish Medicines Agency (EudraCT no: 2011000809-42), and the Danish Data Protection Unit. All participants gave their written informed consent prior to inclusion. The Good Clinical Practice (GCP) Unit at Copenhagen University Hospital monitored the study, and it was registered at http://www.clinicaltrials.gov (NCT01504386). We included women scheduled for robotassisted laparoscopic hysterectomy who met the eligibility criteria. Inclusion criteria were women
Blinding and randomisation The design was a prospective, randomised, placebo-controlled study, blinded both for patients, investigator, and staff involved in data collection, and the study was reported according to the CONSORT (Consolidated Standards of Reporting Trials) guidelines.13 We analysed the data when still blinded for treatment groups, and the codes were not broken until all data analyses were done. We randomised the patients to receive either bilateral TAP block (ropivacaine 0.5%, 20 ml on each side) or placebo block (isotonic saline 0.9%, 20 ml on each side). The regional pharmacy dispensed the active and placebo medications into neutral ampoules identical in appearance, according to a computer-generated randomisation list in blocks of 10. The syringes were pre-packed in sealed boxes labelled with protocol and randomisation numbers. Each patient was assigned to get the medication in the box matching their randomisation number.
Prior to operation, the nurses at the Department of Gynaecology gave all patients paracetamol 1 g and an NSAID (either diclofenac 50 mg or ibuprofen 400 mg; see Table 1) as routine premedication. After induction of anaesthesia, we visualised the TAP with ultrasound scan (LogiQ, GE Healthcare, Buckinghamshire, UK) and placed either a TAP block or placebo block bilaterally, at the level of the umbilicus in the mid-axillary line, using an 80 mm Stimuplex needle (Braun, Melsungen, Germany). To avoid intra-vasal injection, we made a negative aspiration both before injection and after every 5 ml of solution injected. One of four experienced anaesthetists (H. T., E. G. H., M. B., or A. U. M.) placed all TAP blocks, and
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Fig. 1. Study flow diagram. TAP, transversus abdominis plane.
treatment with paracetamol and NSAID may be sufficient. Mild pain (equal to VAS pain below 30 mm) makes it difficult to detect any possible effect of an analgesic technique.19 Three randomised studies and one case-control study have investigated the efficiency of TAP block after conventional laparoscopic hysterectomy.9–12 Our results confirm the findings of the single-blinded study, including only benign laparoscopic hysterectomies,9 as they found neither a reduction in pain scores nor a decrease in opioid consumption as their secondary outcomes.
However, there are many differences between our studies that make it difficult to compare directly, as they used two different laparoscopic techniques and they placed the TAP block after surgery but before emergence. Studies suggest that the TAP block might reduce pain more effectively in the first post-operative hours when placed prior to surgery.20 Their measurements were obtained at 2 and 24 h after surgery, and the perioperative use of pain medication was not reported, which could have influenced the pain scores at 2 h, post-operatively. Acta Anaesthesiologica Scandinavica 59 (2015) 928–935
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error and 20% risk of type 2 error, 28 patients would be needed in each group. To ensure enough patients in case of dropouts, a total of 80 patients were planned for inclusion. For statistical analyses, we used SPSS version 19 (IBM SPSS Statistics; IBM Corporation, Armonk, NY, USA) and described all results as means and standard deviations or median and inter-quartiles as appropriate. Ratio interval and rank scale data were compared with Mann–Whitney’s test between groups. For pain score, the area under the curve (AUC) was estimated and compared with Mann–Whitney’s test between groups. Categorical data were compared with Fisher’s exact test. We chose a 5% significance level for all data. Results We planned to include 80 patients. However, the study was terminated prematurely after 70 included patients due to local restructuring, which made further patient accrual impossible. Of the 70 patients, 65 completed the study – 34 receiving TAP block with ropivacaine (TAP block group) and 31 receiving placebo block with NaCl (placebo group). Reasons for dropouts are given in the CONSORT flowchart (Fig. 1). The two groups were comparable at baseline (Table 1). Because of protocol violation, five patients received oral morphine 20 mg, and 11 patients received i.v. dexamethasone 4 mg as premedication. These patients were randomly distributed between the two groups, and no differences in outcome were found whether they were included or excluded from statistical analyses. We found no differences in total median (interquartile) i.v. morphine consumption the first 24 h post-operatively between the TAP block group [17.5 mg (6.9–36.0 mg)] and the placebo group [17.5 mg (2.9–38.0 mg)] (95% confidence interval 10.0–22.6 mg, P = 0.648). Supplementary morphine given the first hour in the PACU was not different between the two groups (P = 0.467). The median (interquartile) AUC/1–24 h VAS pain while coughing was 20 (11–37) mm in the TAP block group and 21 (6–30) mm in the placebo group (P = 0.345). At rest, the median (interquartile) AUC/1–24 h VAS pain was 12 (3–20) mm in the TAP block group and 7 (1– 19) mm in the placebo group (P = 0.112) (Fig. 2). Post hoc analyses showed that median
(interquartile) VAS pain at rest after first hour was 42 (18–63) mm in TAP block group and 40 (10–52) mm in the placebo group (P = 0.519). VAS pain while coughing after first hour was 43 (14–60) mm in TAP block group and 50 (10– 65) mm in the placebo group (P = 0.903). Distribution of PONV in the two groups is shown in Table 2. No differences in nausea were found between the two groups at any of the observed time points. Number of vomit episodes were not different between the two groups (P = 0.081). No serious adverse events were reported from the two groups. In July 2012, approximately halfway through the inclusions, the Department of Gynaecology changed diclofenac for ibuprofen as standard pain medication for laparoscopic hysterectomy (Table 2). No differences in type of NSAID were found between the two groups (P = 0.805). Discussion Our study is the first to investigate TAP block after robot-assisted laparoscopic hysterectomy. We found that TAP block combined with paracetamol and NSAID treatment had no effect on morphine consumption, VAS pain scores, or frequency of nausea compared with paracetamol and NSAID treatment alone. The robot-assisted technique has possible advantages over traditional laparoscopic hysterectomy, as it is associated with fewer post-operative complications and conversions to laparotomy, as well as it reduces the LOS at the hospital.1 However, in terms of post-operative analgesic use, the two techniques may be comparable.14 NSAIDs have in a multicentre study been shown to reduce morphine requirement and reduce pain (VAS) after open total abdominal hysterectomy.15 Also, NSAIDs are known to have a 30–50% sparing effect on morphine consumption as well as it decreases the side effects of PCA morphine, for example, PONV.16 Our patients reported low median VAS pain scores (25 mm or less) from 2–24 h in both groups – both at rest and while coughing. Other studies have also reported low VAS scores after laparoscopic hysterectomies,17,18 indicating that this procedure may be less painful and to an extent that the basic
Acta Anaesthesiologica Scandinavica 59 (2015) 928–935 ª 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd
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Fig. 1. Study flow diagram. TAP, transversus abdominis plane.
treatment with paracetamol and NSAID may be sufficient. Mild pain (equal to VAS pain below 30 mm) makes it difficult to detect any possible effect of an analgesic technique.19 Three randomised studies and one case-control study have investigated the efficiency of TAP block after conventional laparoscopic hysterectomy.9–12 Our results confirm the findings of the single-blinded study, including only benign laparoscopic hysterectomies,9 as they found neither a reduction in pain scores nor a decrease in opioid consumption as their secondary outcomes.
However, there are many differences between our studies that make it difficult to compare directly, as they used two different laparoscopic techniques and they placed the TAP block after surgery but before emergence. Studies suggest that the TAP block might reduce pain more effectively in the first post-operative hours when placed prior to surgery.20 Their measurements were obtained at 2 and 24 h after surgery, and the perioperative use of pain medication was not reported, which could have influenced the pain scores at 2 h, post-operatively. Acta Anaesthesiologica Scandinavica 59 (2015) 928–935
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Fig. 2. Visual analogue scale (VAS) pain scores at rest and while coughing in the transversus abdominis plane (TAP) block group versus placebo group at 1–24 h post-operatively.
Table 2 Morphine consumption and side effect (PONV) Group TAP block (n = 34) Morphine in 24 h (mg) Morphine first hour in PACU (mg) Patients with vomit episodes (n) Patients receiving ondansetron (n) Patients receiving other antiemetic (n)
17.5 (6.9–35.6) 5 (0–16) 10 21 4 None/mild
Nausea Nausea Nausea Nausea Nausea Nausea
at at at at at at
1 h (n) 2 h (n) 4 h (n) 8 h (n) 18 h (n) 24 h (n)
Group placebo (n = 31)
31 32 28 29 32 31
17.5 (2.9–37.5) 5 (0–10) 16 21 3 Moderate/severe 3 2 6 5 2 3
None/mild
Moderate/severe
26 30 25 27 31 27
4 1 6 4 0 3
All data are given as median and interquartile range, or number. PACU, Post-Anaesthesia Care Unit; PONV, post-operative nausea and vomiting; TAP, transversus abdominis plane.
In a recent published randomised blinded study with almost 200 participants using TAP block with bupivacaine, the authors found no differences in opioid requirements.12 However, they did find a decrease in VAS pain at the time of discharge from 3.8 in the TAP group to 3.1 in the control group, but follow up at 24, 48, and 72 after surgery showed no differences in VAS pain scores between the two groups. This questions the clinical relevance for TAP block after laparoscopic hysterectomy as a basic analgesic regimen may be sufficient in most patients to reduce pain to low levels, where it will be more difficult to show an effect of an add-on treatment as a TAP block.
The double-blinded study10 comparing two different concentrations of ropivacaine (0.5% and 0.25%) with placebo-block (NaCl) found that the 0.5% ropivacaine concentration reduced the mean 24 h opioid consumption from 15 mg to 7.5 mg. No differences were detected between the 0.25% ropivacaine group and placebo-group. The study did not describe where the portholes were placed, and had no results on pain scores between the first and 24 h. However, it is debatable if this rather small reduction in morphine requirement is clinically relevant, as they reported no reduction in morphine related side effects, such as PONV.
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The origin of pain after hysterectomy is believed to come from both somatic and visceral components. The TAP block potentially covers the thoracolumbar nerves (T6-L1) in the abdominal wall and would therefore be effective for pain relief in skin and muscle incisions depending on where the TAP block is placed. In open hysterectomies, TAP block seems to decrease the morphine consumption and the VAS pain scores8 and perhaps adding dexamethasone to the local anaesthetic in the TAP group could be even more effective against pain.21,22 Pain from the skin incisions in open surgery is considerably worse than in laparoscopic surgery, and this might be the reason why TAP block shows more positive results in open hysterectomies compared with the minimal invasive procedures. The TAP block is not believed to cover visceral pain, unless there is a systemic effect by absorption of the local anaesthetics to the systemic circulation.22 This is not well documented for TAP block and should be investigated in the future. Studies have suggested that absorption of the local anaesthetics used in TAP blocks might be greater than in other peripheral blocks, actually with a potential risk of systemic toxicity.;23,24 Future studies are needed to determine the optimal concentrations and volume of the local anaesthetic for an effective TAP block, without risking intoxication of the patient. The strengths of our study is the study design, with a double-blinded, randomised placebo-controlled approach according to GCP and CONSORT guidelines, and the use of PCA with morphine, eliminating the bias of the nurses’ judgement of needed medications. One limitation of our study is that five of the patients received oral morphine 20 mg and 11 patients received dexamethasone 4 mg i.v. prior to surgery, which was a violation to the protocol. However, they were equally spread between the two groups. Another limitation is that the VAS scores were achieved by several different nurses, which could influence the way of asking the patients. We tried to eliminate this bias by educating all involved nurses, had written instructions, and the primary investigator called the nurse in charge 10 min prior to all data collections. Finally, our study was terminated prematurely, and we ended up including less than the 80 patients originally planned, but still more than in the sample size calculation of
2 9 28 patients. However, opioid consumption and pain scores were lower than expected, and inclusion of the actual planned number of patients would have strengthened the results of the study. TAP block is increasingly used worldwide as a supplement for post-operative analgesia after various abdominal surgical procedures. However, the many randomised trials published so far are difficult to compare, as different local anaesthetics, doses, volume, and placement of the TAP blocks are used. Future research is needed to clarify for which procedures TAP block can be recommended. In conclusion, the present study was not able to show that bilateral TAP block on top of a basic analgesic regimen with paracetamol and NSAID could reduce morphine consumption, VAS pain scores, or PONV after robot-assisted laparoscopic hysterectomy.
Acknowledgements The authors want to thank the Department of Anaesthesia, the Post-Operative Care Unit (PACU), and the Department of Gynecology at Herlev University Hospital for their effort to help and support the study. We would also like to thank Smith Medical for providing PCA devices (CADD Solis) for the study. References 1. Scandola M, Grespan L, Vicentini M, Fiorini P. Robot-assisted laparoscopic hysterectomy vs traditional laparoscopic hysterectomy: five metaanalyses. J Minim Invasive Gynecol 2011; 18: 705–15. 2. O’Neill M, Moran PS, Teljeur C, O’Sullivan OE, O’Reilly BA, Hewitt M, Flattery M, Ryan M. Robotassisted hysterectomy compared to open and laparoscopic approaches: systematic review and metaanalysis. Arch Gynecol Obstet 2013; 287: 907–18. 3. Abdallah FW, Chan VW, Brull R. Transversus abdominis plane block: a systematic review. Reg Anesth Pain Med 2012; 37: 193–209. 4. Johns N, O’Neill S, Ventham NT, Barron F, Brady RR, Daniel T. Clinical effectiveness of transversus abdominis plane (TAP) block in abdominal surgery: a systematic review and meta-analysis. Colorectal Dis 2012; 14: e635–642. Acta Anaesthesiologica Scandinavica 59 (2015) 928–935
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5. Mishriky BM, George RB, Habib AS. Transversus abdominis plane block for analgesia after Cesarean delivery: a systematic review and meta-analysis. Can J Anaesth 2012; 59: 766–78. 6. Petersen PL, Mathiesen O, Torup H, Dahl JB. The transversus abdominis plane block: a valuable option for postoperative analgesia? A topical review. Acta Anaesthesiol Scand 2010; 54: 529–35. 7. Charlton S, Cyna AM, Middleton P, Griffiths JD. Perioperative transversus abdominis plane (TAP) blocks for analgesia after abdominal surgery. Cochrane Database Syst Rev 2010; (12): CD007705. 8. Champaneria R, Shah L, Geoghegan J, Gupta JK, Daniels JP. Analgesic effectiveness of transversus abdominis plane blocks after hysterectomy: a metaanalysis. Eur J Obstet Gynecol Reprod Biol 2013; 166: 1–9. 9. Kane SM, Garcia-Tomas V, Alejandro-Rodriguez M, Astley B, Pollard RR. Randomized trial of transversus abdominis plane block at total laparoscopic hysterectomy: effect of regional analgesia on quality of recovery. Am J Obstet Gynecol 2012; 207: 419.e1–5. 10. De. Oliveira GSJ, Milad MP, Fitzgerald P, Rahmani R, McCarthy RJ. Transversus abdominis plane infiltration and quality of recovery after laparoscopic hysterectomy: a randomized controlled trial. Obstet Gynecol 2011; 118: 1230–37. 11. Pather S, Loadsman JA, Gopalan PD, Rao A, Philp S, Carter J. The role of transversus abdominis plane blocks in women undergoing total laparoscopic hysterectomy: a retrospective review. Aust N Z J Obstet Gynaecol 2011; 51: 544–7. 12. Calle GA, Lopez CC, Sanchez E, De Los Rios JF, Vasquez EM, Serna E, Arango AM, Casta~ neda JD, Vasquez RA, Gonz alez A, Escobar A, Almanza LA. Transversus abdominis plane block after ambulatory total laparoscopic hysterectomy: randomized controlled trial. Acta Obstet Gynecol Scand 2014; 93: 345–50. 13. Schulz KF, Altman DG, Moher D. CONSORT 2010 Statement: updated guidelines for reporting parallel group randomised trials. Trials 2010; 11: 32. 14. Sarlos D, Kots L, Stevanovic N, von Felten S, Schar G. Robotic compared with conventional laparoscopic hysterectomy: a randomized controlled trial. Obstet Gynecol 2012; 120: 604–611. 15. Kroll PB, Meadows L, Rock A, Pavliv L. A multicenter, randomized, double-blind, placebocontrolled trial of intravenous ibuprofen (i.v.-
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