Correspondence
[1]. His argument seems compelling but merits further discussion. Firstly, as there is no uniform, objective definition of ‘difficult mask ventilation’ [1, 2], the evidence from which Patel draws his conclusions is undermined by the diversity of definition and the subjectivity of measurement. Secondly, difficult mask ventilation occurs rarely, making it difficult to study in sufficiently powered studies. The meticulous work by Sachdeva et al. illustrates this [3], being the largest such study to date, but including only 125 participants. Patel suggests that test ventilation may lighten anaesthesia and promote difficulty. Although a valid concern, there is no proof that this actually happens. I seldom test-ventilate, but occasionally do so to guide the choice of neuromuscular blocking drug, failed test ventilation being a trigger for suxamethonium administration [4]. Patel objects that it is ‘not inconceivable’ that serious hypoxia will occur before spontaneous ventilation resumes after suxamethonium, which is correct but preferable to prolonged hypoxia. Finally, Patel is bold to state that difficult mask ventilation ‘never deteriorates’ after neuromuscular blocking drugs are administered, when anaphylaxis and bronchospasm are recognised complications of these drugs, and which can make difficult mask ventilation impossible. J. Nielsen Concord Hospital, Sydney, Australia Email: [email protected] No external funding and no competing interests declared. Previously
Anaesthesia 2014, 69, 1287–1297
posted on the Anaesthesia correspondence website: www.anaesthe siacorrespondence.com.
References 1. Patel A. Facemask ventilation before or after neuromuscular blocking drugs: where are we now? Anaesthesia 2014; 69: 811–5. 2. El-Orbany M, Woehlck HJ. Difficult mask ventilation. Anesthesia and Analgesia 2009; 109: 1870–80. 3. Sachdeva R, Kannan TR, Mendonca C, Patteril M. Evaluation of changes in tidal volume during mask ventilation following administration of neuromuscular blocking drugs. Anaesthesia 2014; 69: 826–32. 4. Amathieu R, Combes X, Agdi W, et al. An algorithm for difficult airway management, modified for modern optical devices (Airtraq laryngoscope; LMA CTrachTM): a 2-year prospective validation in patients for elective abdominal, gynecologic, and thyroid surgery. Anesthesiology 2011; 114: 25–33. doi:10.1111/anae.12846
Extended roles for videolaryngoscopy We read with interest two recent articles describing novel uses of newer laryngoscopes. Montague et al. described the placement of nasopharyngeal airways and Jaques catheters under direct vision using the GlideScopeTM (Verathon Medical United Kingdom Ltd, High Wycombe, UK) in patients having cleft palate repair [1]. Likewise, Gordon et al. Used the GlideScope to inspect the airway, with minimal stimulation, following facial reconstructive surgery [2]. Similarly, we have found the AirtraqTM Optical Laryngoscope (Prodol Meditec SA, Vizcaya, Spain) of use following thyroid surgery. A significant complication of such surgery is
© 2014 The Association of Anaesthetists of Great Britain and Ireland
recurrent laryngeal nerve damage and associated vocal cord palsy. Surgeons routinely ask anaesthetists to ‘check the cords’ at extubation. This is important clinically and functionally, but also has medicolegal implications. A traditional approach to this is to extubate the trachea whilst the patient is deeply anaesthetised and perform direct laryngoscopy with a Macintosh blade. This is often difficult: firstly, the depth of anaesthesia must be judged correctly as performing direct laryngoscopy in a spontaneously breathing patient is extremely stimulating and may provoke laryngospasm [3]. Secondly, the patient is often still positioned to facilitate neck surgery rather than direct laryngoscopy; further, this technique can only be used when the cords have actually been directly viewed at the original intubation. If asymmetrical movement of the vocal cords is suspected, the surgeons will often attempt to look at the cords while the anaesthetist is preforming direct laryngoscopy, a somewhat awkward manoeuvre. We now routinely observe cord function by performing indirect laryngoscopy using the Airtraq after thyroid surgery, after tracheal extubation under deep anaesthesia. This has many advantages: it is less stimulating than the full traction required by direct laryngoscopy and so is less likely to precipitate laryngospasm; it permits us to view cord movement in most patients in whom direct laryngoscopy fails to reveal the larynx; and it allows the surgeon to see the cords easily – especially when using a remote viewing monitor. Finally, 1293
Anaesthesia 2014, 69, 1287–1297
the image of fully abducted and adducted cords can be recorded digitally and stored, should recurrent laryngeal nerve function be queried post operatively. R. Sandu University Hospital Aintree, Liverpool, UK A. Higgs Warrington and Halton Hospitals NHS Foundation Trust, Cheshire, UK Email: [email protected] No external funding or competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesiacorrespon dence.com.
References 1. Montague J, Cadier M, Williams S. Novel uses of the GlidescopeTM in cleft palate surgery. Anaesthesia 2014; 69: 393. 2. Gordon JK, Rodney G, Ball DR. Extended roles for videolaryngoscopy. Anaesthesia 2014; 69: 793. 3. Popat M, Mitchell V, Dravid R, Patel A, Swampilli C, Higgs A. Difficult Airway Society guidelines for the management of tracheal extubation. Anaesthesia 2012; 67: 318–40. doi:10.1111/anae.12875
Novel use of the PECS II block for upper limb fistula surgery We read with interest the article by Blanco et al regarding the PECS I block [1] and would like to describe a novel use of the PECS II block for upper limb fistula surgery. The use of brachial plexus blockade to provide anaesthesia for upper limb fistula formation in patients with end-stage renal failure is a safe 1294
Correspondence
and well established technique that can provide ideal surgical conditions and patient comfort [2, 3]. However, for upper arm fistula creation, e.g. brachial-cephalic fistulae, a brachial plexus block alone may not adequately block the intercostobrachial nerve, a branch of the second intercostal nerve that supplies the medial aspect of the upper arm [4]. Failure to block this nerve adequately results in pain/discomfort, disrupts surgery and requires additional local anaesthetic supplementation by the surgeon. We describe a novel use of the PECS II block to supplement supraclavicular brachial plexus block to provide complete anaesthesia of the upper arm for fistula creation surgery. The PECS II block, a modification of the PECS I block [1] and originally described for use in breast surgery, involves placing local anaesthetic between the pectoralis minor muscle and serratus anterior muscle under ultrasound guidance [5]. This block is fast, easy to perform and reliable, and provides blockade of the intercostobrachial nerve and thus the medial aspect of the upper arm [5]. We have combined supraclavicular brachial plexus block and PECS II block in a small number of patients for upper arm fistula creation. These patients remained comfortable throughout the procedure, had complete anaesthesia of the surgical site and did not require any additional local anaesthetic supplementation by the surgeon, whilst we have not seen any complications so far; however, further studies with larger numbers of patients are required.
N. Purcell D. Wu Orange Health Service, NSW, Australia Email: [email protected] No external funding or competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesiacorrespon dence.com.
References 1. Blanco R. The ‘pecs block’: a novel technique for providing analgesia after breast surgery. Anaesthesia 2011; 66: 847–8. 2. Hingorani AP, Ascher E, Gupta P, et al. Regional anesthesia: preferred technique for venodilation in the creation of upper extremity arteriovenous fistulae. Vascular 2006; 14: 23–6. 3. Sariguney D, Mahli A, Coskun D. The extent of blockade following axillary and infraclavicular approaches of brachial plexus block in uremic patients. Journal of Clinical Medicine Research 2012; 4: 26–32. 4. Neal JM, Gerancher JC, Hebl JR, et al. Upper extremity regional anesthesia: essentials of our current understanding, 2008. Regional Anesthesia and Pain Medicine 2009; 34: 134–70. 5. Blanco R, Fajardo M, Parras Maldonado T. Ultrasound description of PECS II (modified PECS I): a novel approach to breast surgery. Revista Espanola de Anestesiologica y Reanimacion 2012; 59: 470–5. doi:10.1111/anae.12876
‘Special’ fluids I would like to clarify a common misunderstanding demonstrated by Drs Grimes and Levy in their letter regarding 5% dextrose with 0.45% sodium chloride solutions [1] in response to recent editorials about new National Institute for Health and Care Excellence (NICE) guidelines on intravenous fluid administration [2, 3]. They point out that this mixture is classified as a ‘spe-
© 2014 The Association of Anaesthetists of Great Britain and Ireland
[1]. His argument seems compelling but merits further discussion. Firstly, as there is no uniform, objective definition of ‘difficult mask ventilation’ [1, 2], the evidence from which Patel draws his conclusions is undermined by the diversity of definition and the subjectivity of measurement. Secondly, difficult mask ventilation occurs rarely, making it difficult to study in sufficiently powered studies. The meticulous work by Sachdeva et al. illustrates this [3], being the largest such study to date, but including only 125 participants. Patel suggests that test ventilation may lighten anaesthesia and promote difficulty. Although a valid concern, there is no proof that this actually happens. I seldom test-ventilate, but occasionally do so to guide the choice of neuromuscular blocking drug, failed test ventilation being a trigger for suxamethonium administration [4]. Patel objects that it is ‘not inconceivable’ that serious hypoxia will occur before spontaneous ventilation resumes after suxamethonium, which is correct but preferable to prolonged hypoxia. Finally, Patel is bold to state that difficult mask ventilation ‘never deteriorates’ after neuromuscular blocking drugs are administered, when anaphylaxis and bronchospasm are recognised complications of these drugs, and which can make difficult mask ventilation impossible. J. Nielsen Concord Hospital, Sydney, Australia Email: [email protected] No external funding and no competing interests declared. Previously
Anaesthesia 2014, 69, 1287–1297
posted on the Anaesthesia correspondence website: www.anaesthe siacorrespondence.com.
References 1. Patel A. Facemask ventilation before or after neuromuscular blocking drugs: where are we now? Anaesthesia 2014; 69: 811–5. 2. El-Orbany M, Woehlck HJ. Difficult mask ventilation. Anesthesia and Analgesia 2009; 109: 1870–80. 3. Sachdeva R, Kannan TR, Mendonca C, Patteril M. Evaluation of changes in tidal volume during mask ventilation following administration of neuromuscular blocking drugs. Anaesthesia 2014; 69: 826–32. 4. Amathieu R, Combes X, Agdi W, et al. An algorithm for difficult airway management, modified for modern optical devices (Airtraq laryngoscope; LMA CTrachTM): a 2-year prospective validation in patients for elective abdominal, gynecologic, and thyroid surgery. Anesthesiology 2011; 114: 25–33. doi:10.1111/anae.12846
Extended roles for videolaryngoscopy We read with interest two recent articles describing novel uses of newer laryngoscopes. Montague et al. described the placement of nasopharyngeal airways and Jaques catheters under direct vision using the GlideScopeTM (Verathon Medical United Kingdom Ltd, High Wycombe, UK) in patients having cleft palate repair [1]. Likewise, Gordon et al. Used the GlideScope to inspect the airway, with minimal stimulation, following facial reconstructive surgery [2]. Similarly, we have found the AirtraqTM Optical Laryngoscope (Prodol Meditec SA, Vizcaya, Spain) of use following thyroid surgery. A significant complication of such surgery is
© 2014 The Association of Anaesthetists of Great Britain and Ireland
recurrent laryngeal nerve damage and associated vocal cord palsy. Surgeons routinely ask anaesthetists to ‘check the cords’ at extubation. This is important clinically and functionally, but also has medicolegal implications. A traditional approach to this is to extubate the trachea whilst the patient is deeply anaesthetised and perform direct laryngoscopy with a Macintosh blade. This is often difficult: firstly, the depth of anaesthesia must be judged correctly as performing direct laryngoscopy in a spontaneously breathing patient is extremely stimulating and may provoke laryngospasm [3]. Secondly, the patient is often still positioned to facilitate neck surgery rather than direct laryngoscopy; further, this technique can only be used when the cords have actually been directly viewed at the original intubation. If asymmetrical movement of the vocal cords is suspected, the surgeons will often attempt to look at the cords while the anaesthetist is preforming direct laryngoscopy, a somewhat awkward manoeuvre. We now routinely observe cord function by performing indirect laryngoscopy using the Airtraq after thyroid surgery, after tracheal extubation under deep anaesthesia. This has many advantages: it is less stimulating than the full traction required by direct laryngoscopy and so is less likely to precipitate laryngospasm; it permits us to view cord movement in most patients in whom direct laryngoscopy fails to reveal the larynx; and it allows the surgeon to see the cords easily – especially when using a remote viewing monitor. Finally, 1293
Anaesthesia 2014, 69, 1287–1297
the image of fully abducted and adducted cords can be recorded digitally and stored, should recurrent laryngeal nerve function be queried post operatively. R. Sandu University Hospital Aintree, Liverpool, UK A. Higgs Warrington and Halton Hospitals NHS Foundation Trust, Cheshire, UK Email: [email protected] No external funding or competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesiacorrespon dence.com.
References 1. Montague J, Cadier M, Williams S. Novel uses of the GlidescopeTM in cleft palate surgery. Anaesthesia 2014; 69: 393. 2. Gordon JK, Rodney G, Ball DR. Extended roles for videolaryngoscopy. Anaesthesia 2014; 69: 793. 3. Popat M, Mitchell V, Dravid R, Patel A, Swampilli C, Higgs A. Difficult Airway Society guidelines for the management of tracheal extubation. Anaesthesia 2012; 67: 318–40. doi:10.1111/anae.12875
Novel use of the PECS II block for upper limb fistula surgery We read with interest the article by Blanco et al regarding the PECS I block [1] and would like to describe a novel use of the PECS II block for upper limb fistula surgery. The use of brachial plexus blockade to provide anaesthesia for upper limb fistula formation in patients with end-stage renal failure is a safe 1294
Correspondence
and well established technique that can provide ideal surgical conditions and patient comfort [2, 3]. However, for upper arm fistula creation, e.g. brachial-cephalic fistulae, a brachial plexus block alone may not adequately block the intercostobrachial nerve, a branch of the second intercostal nerve that supplies the medial aspect of the upper arm [4]. Failure to block this nerve adequately results in pain/discomfort, disrupts surgery and requires additional local anaesthetic supplementation by the surgeon. We describe a novel use of the PECS II block to supplement supraclavicular brachial plexus block to provide complete anaesthesia of the upper arm for fistula creation surgery. The PECS II block, a modification of the PECS I block [1] and originally described for use in breast surgery, involves placing local anaesthetic between the pectoralis minor muscle and serratus anterior muscle under ultrasound guidance [5]. This block is fast, easy to perform and reliable, and provides blockade of the intercostobrachial nerve and thus the medial aspect of the upper arm [5]. We have combined supraclavicular brachial plexus block and PECS II block in a small number of patients for upper arm fistula creation. These patients remained comfortable throughout the procedure, had complete anaesthesia of the surgical site and did not require any additional local anaesthetic supplementation by the surgeon, whilst we have not seen any complications so far; however, further studies with larger numbers of patients are required.
N. Purcell D. Wu Orange Health Service, NSW, Australia Email: [email protected] No external funding or competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesiacorrespon dence.com.
References 1. Blanco R. The ‘pecs block’: a novel technique for providing analgesia after breast surgery. Anaesthesia 2011; 66: 847–8. 2. Hingorani AP, Ascher E, Gupta P, et al. Regional anesthesia: preferred technique for venodilation in the creation of upper extremity arteriovenous fistulae. Vascular 2006; 14: 23–6. 3. Sariguney D, Mahli A, Coskun D. The extent of blockade following axillary and infraclavicular approaches of brachial plexus block in uremic patients. Journal of Clinical Medicine Research 2012; 4: 26–32. 4. Neal JM, Gerancher JC, Hebl JR, et al. Upper extremity regional anesthesia: essentials of our current understanding, 2008. Regional Anesthesia and Pain Medicine 2009; 34: 134–70. 5. Blanco R, Fajardo M, Parras Maldonado T. Ultrasound description of PECS II (modified PECS I): a novel approach to breast surgery. Revista Espanola de Anestesiologica y Reanimacion 2012; 59: 470–5. doi:10.1111/anae.12876
‘Special’ fluids I would like to clarify a common misunderstanding demonstrated by Drs Grimes and Levy in their letter regarding 5% dextrose with 0.45% sodium chloride solutions [1] in response to recent editorials about new National Institute for Health and Care Excellence (NICE) guidelines on intravenous fluid administration [2, 3]. They point out that this mixture is classified as a ‘spe-
© 2014 The Association of Anaesthetists of Great Britain and Ireland
