instructions, to one of the approaches described in Fig. 1. The residents had ﬁve minutes to read the instructions and were given a timed (maximum of 5 min) attempt to obtain a clear ultrasound image of the brachial plexus on a naive volunteer model (BMI 20.6 kg.m2). After one hour, each resident was given sealed instructions for the other approach, and the procedure was repeated. A portable TITAN ultrasound machine (SonoSite Inc., Bothell, WA, USA) with a C11e, 11 mm footprint, 8–5 MHz probe was used for scanning . On the ﬁrst attempt, 1/6 (16.7%) residents using the local sonoanatomy landmark approach successfully obtained a clear image of the brachial plexus at the interscalene level, compared with 5/5 of the residents (100%) using the traceback method. On the second attempt, 2/5 (40%) of those using the local sonoanatomy landmark method were successful, compared with 6/6 (100%) residents using the traceback approach. Compared with the local sonoanatomy landmark method, residents using the traceback method were able to obtain acceptable images of the brachial plexus at the interscalene level with a high degree of success. The traceback approach may be a useful training aid for practitioners who have little or no experience in ultrasound-guided regional anaesthesia.
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assistance with the study and D. Gareth Corry for assistance with manuscript preparation. B. C. Tsui University of Alberta Edmonton, Canada Email: [email protected]
L. Lou University of Calgary Calgary, Canada This work was supported in part by an Education and Research Fund, Department of Anesthesiology and Pain Medicine, University of Alberta Hospitals, Edmonton, Canada. BCT is supported by a Clinical Investigator Award from the Alberta Heritage Foundation for Medical Research.
References 1. Sites BD, Gallagher JD, Cravero J, Lundberg J, Blike G. The learning curve associated with a simulated ultrasoundguided interventional task by inexperienced anesthesia residents. Regional Anesthesia and Pain Medicine 2004; 29: 544–8. 2. Davies T, Townsley P, Jlala H, et al. Novice performance of ultrasoundguided needle advancement: standard 38-mm transducer vs 25-mm hockey stick transducer. Anaesthesia 2012; 67: 855–61. 3. Gupta RK, Lane J, Allen B, Shi Y, Schildcrout JS. Improving needle visualization by novice residents during an in-plane ultrasound nerve block simulation using an in-plane multiangle needle guide. Pain Medicine 2013 Jun 11; doi 10. 1111/pme.12160. 4. Tsui BCH. Atlas of Ultrasound and Nerve Stimulation-Guided Regional Anesthesia. New York, Springer, 2007. p. 68. 5. Tsui BC, Doyle K, Chu K, Pillay J, Dillane D. Case series: ultrasound-guided supraclavicular block using a curvilinear probe in 104 day-case hand surgery patients. Canadian Journal of Anesthesia 2009; 56: 46–51.
The author wishes to thank Dr Brendan Finucane, Dr Ravi Bhargava, and Jennifer Pillay for © 2013 The Association of Anaesthetists of Great Britain and Ireland
Intrapleural blocks for chest wall surgery We read with interest both the description of the serratus plane block , and the accompanying editorial  in Anaesthesia. The discussion regarding pre-existing regional anaesthetic techniques appropriate for chest wall surgery included mention of interpleural blocks. Despite acknowledging the production of ‘reliable unilateral segmental thoracic analgesia’ , interpleural blocks were only brieﬂy referred to and then largely dismissed owing to the lack of published data and a quoted 2% risk of pneumothorax. The pneumothorax risk quoted comes from the review by Dravid and Paul published in Anaesthesia in 2007 , in turn obtained from a separate retrospective literature review of 703 cases , among which a variety of techniques were used. In fact, Dravid and Paul acknowledged that “the true incidence of pneumothorax may never be known”. We believe that our hospital has performed the world’s largest series of interpleural blocks, more than 7000 performed since 1994. We use the ‘saline infusion technique’ to site interpleural blocks correctly [5, 6]. After the ﬁrst few hundred patients, our radiology department declined to carry out chest X-rays for each patient because there had been a zero incidence of pneumothorax. Since then, there have been a total of three clinically detectable pneumothoraces (and none in recent years), all of which were attributable to inexperienced trainees’ failing to adhere to the method described. None of these cases required
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treatment beyond supplemental oxygen. The technique is used for all chest wall surgery at our institution, including major breast reconstruction. Suggestions about carrying out randomised controlled trials have been rejected by the surgeons at our hospital because they are already convinced of the beneﬁts from the existing technique. The use of postoperative opioids in these cases is almost non-existent. It is our belief, therefore, that interpleural block is the ideal regional anaesthetic technique for chest wall surgery. We can only presume that (natural) anxiety about passing a 16-G needle through the parietal pleura has prevented more widespread adoption or studies of this technique. C. J. Morris R. Bunsell Stoke Mandeville Hospital Buckinghamshire Healthcare NHS Trust Aylesbury, UK Email: [email protected]
No external funding and no competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesia correspondence.com.
References 1. Blanco R, Parras T, McDonnell JG, PratsGalino A. Serratus plane block: a novel ultrasound guided thoracic wall nerve block. Anaesthesia 2013; 68: 1107–13. 2. Karmakar MK, Tighe SQM. Serratus plane block: do we need to learn another technique for thoracic wall blockade? Anaesthesia 2013; 68: 1103– 06. 3. Dravid RM, Paul RE. Interpleural block – part 2. Anaesthesia 2007; 62: 1143–53. 4. Strømskag KE, Minor BG, Steen PA. Side effects and complications related to
Correspondence interpleural analgesia: an update. Acta Anaesthesiologica Scandinavica 1990; 34: 473–7. 5. Scott PV. Interpleural regional analgesia: detection of the interpleural space by saline infusion. British Journal of Anaesthesia 1991; 66: 131–3. 6. Dravid RM, Paul RE. Interpleural block – part 1. Anaesthesia 2007; 62: 1039–49. doi:10.1111/anae.12550
Pre-operative femoral nerve block vs fascia iliaca block for femoral neck fracture – a reply On behalf of my co-authors, I should like to thank all the correspondents for their comments [1–9] in response to our paper that compared pre-operative fascia iliaca and femoral nerve block in patients with a femoral neck fracture , and will attempt to respond to all the issues raised. Several correspondents have noted that the doses and dilutions used for both nerve stimulatorguided femoral nerve and fascia iliaca compartment blocks were the same, whereas it is customary to perform compartment blocks with a larger volume of more dilute drug. The dose of levobupivacaine we used was based on the maximum single dose recommended for this drug. Given the age and frailty of the cohort, doses were reduced for patients weighing less than 70 kg because of reduced hepatic clearance and smaller volumes of distribution of drugs in old age. For safety through simplicity, drug dilutions were not adjusted for the type of block in this study, as the
design of the study reﬂected current practice in a nurse-led service that has now delivered over 1800 blocks with no complications. It is possible that diluting doses by 25% may make some positive difference to the quality of analgesia achieved with the compartment block, but probably with a negative effect on duration. Several correspondents suggested that ultrasound-guided femoral nerve block may be the ‘gold standard’ technique. However, the challenge of providing equipment, time, expertise and continuous training in emergency departments may well prevent many patients from receiving regional analgesia, given current pressures. A pragmatic decision needs to be made regarding a compromise between quality and quantity where these cannot be both optimally and simultaneously delivered. The concept of ‘total pain relief’ applied to a population may be a useful tool for assessing overall beneﬁt and service planning in this respect. With regard to the observation that administration of opioids before block was limited in our study, it is our experience that the risk-beneﬁt balance of opioid vs regional block strongly favours regional block in these patients, and that it is likely that published guidance on this issue requires updating. As pointed out in our discussion, the pharmacokinetics of opioids are very unpredictable in the elderly, and we witnessed many cases of opioid toxicity requiring treatment before the development of our nerve block service. We would therefore dispute the statement that in these
© 2013 The Association of Anaesthetists of Great Britain and Ireland