Anaesthesia 2017, 72,

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1 3. Koscielniak-Nielsen ZJ. Ultrasoundguided peripheral nerve blocks: what are the benefits? Acta Anaesthesiologica Scandinavica 2008; 52: Lewis SR, Price A, Walker KJ, McGrattan K, Smith AF. Ultrasound guidance for upper and lower limb blocks. Cochrane Database of Systematic Reviews 2015; 11: CD Munirama S, McLeod G. A systematic review and meta-analysis of ultrasound versus electrical stimulation for peripheral nerve location and blockade. Anaesthesia 2015; 70: Halsted WS. Practical comments on the use and abuse of cocaine. New York Medical Journal 1885; 42: Chandra A, Eisma R, Felts P, Munirama S, McLeod G. The feasibility of microultrasound as a tool to image peripheral nerves. Anaesthesia 2017; 72: Bigeleisen PE. Nerve puncture and apparent intraneural injection during ultrasound-guided axillary block does not invariably result in neurologic injury. Anesthesiology 2006; 105: Bigeleisen PE, Moayeri N, Groen GJ. Extraneural versus intraneural stimulation thresholds during ultrasoundguided supraclavicular block. Anesthesiology 2009; 110: Robards C, Hadzic A, Somasundaram L, et al. Intraneural injection with lowcurrent stimulation during popliteal sciatic nerve block. Anesthesia and Analgesia 2009; 109: Chan VWS, Brull R, McCartney CJL, Xu D, Abbas S, Shannon P. An ultrasonographic and histological study of intraneural injection and electrical stimulation in pigs. Anesthesia and Analgesia 2007; 104: Kirchmair L, Str ohle M, L oscher WN, Kreutziger J, Voelckel WG, Lirk P. Neurophysiological effects of needle trauma and intraneural injection in a porcine model: a pilot study. Acta Anaesthesiologica Scandinavica 2016; 60: Liguori GA. Complications of regional anesthesia: nerve injury and peripheral neural blockade. Journal of Neurosurgical Anesthesiology 2004; 16: Brull R, Hadzic A, Reina MA, Barrington MJ. Pathophysiology and etiology of nerve injury following peripheral nerve blockade. Regional Anesthesia and Pain Medicine 2015; 40: Brull R, McCartney CJL, Chan VWS, El- Beheiry H. Neurological complications after regional anesthesia: contemporary estimates of risk. Anesthesia and Analgesia 2007; 104: doi: /anae The erector spinae plane block: plane and simple A new regional anaesthetic block technique is described in this issue of Anaesthesia by Chin et al. whereby local anaesthetic is injected within a plane beneath the erector spinae muscle to achieve analgesia for abdominal surgery [1]. A review of the sono-anatomy presented suggests that this is a simple block to perform, and is probably safe. But is this investigation of yet another new block conducted merely for discovery s sake, or is the erector spinae plane (ESP) block addressing a problem that is crying out for a solution? This editorial accompanies an article by Chin et al., Anaesthesia 2017; 72: Problems To understand the value of new techniques, we need to explore how they refine current practice. Improved standards in peri-operative care can be attributed to a wide range of changes to clinical conventions. One of the most significant breakthroughs in recent times has been the introduction and global uptake of enhanced recovery after surgery (ERAS) [2], particularly in the cohort of patients having abdominal surgery. Early pre-operative assessment, screening, education and optimisation complements perioperative measures such as carbohydrate loading, antibiotic prophylaxis, thromboprophylaxis, thermoregulation, goal-directed fluid therapy and multimodal analgesia [3]. There remains limited high-quality evidence regarding the value of each element [4], contributing to heterogeneity in the precise components of existing protocols. However, the overarching concept of a bundle of peri-operative interventions to improve outcomes can be both costeffective and globally applied [5, 6]. The responsibility thus falls to the anaesthetist to modify management to increase both quality and outcomes of peri-operative care. Multimodal analgesia is critical both to ERAS [2] and to achieve the target of DREAMing (DRinking, EAting and Mobilising) [7]. Regional anaesthesia complements and enhances multimodal analgesia for abdominal The Association of Anaesthetists of Great Britain and Ireland

2 Anaesthesia 2017, 72, surgery, with its role increasingly recognised [8], and may indeed alter outcomes [9 11]. However, which regional anaesthetic technique is most appropriate, efficacious, safe, timely and consistent in the hands of most practitioners remains highly debated. Moreover, the possible permutations for achieving goals of ERAS are virtually limitless, leaving practitioners with no gold standard in peri-operative analgesic strategies. Solutions Thoracic epidural analgesia has long been viewed as the standard analgesic blueprint to avoid systemic opioids and the adverse effects accompanying them [12 14]. Although effective analgesic outcomes are certainly evident, thoracic epidural analgesia does not reliably reduce hospital stay, incidence of ileus, or postoperative complications after open abdominal surgery [15]. In minimally-invasive abdominal surgery, however, the data lends very little support for the use of epidural analgesia as part of a multimodal strategy. For example, in the USA, epidural analgesia is only used in around 2% of laparoscopic procedures and when this approach is used, it is associated with increased hospital stay and healthcare costs, and may potentially have a greater complication rate compared with conventional analgesic strategies [16]. These effects precisely contradict the goals of ERAS, and have led to some calling for epidural analgesia to be withdrawn from ERAS pathways [17]. Similarly, intrathecal analgesia has been incorporated in some ERAS protocols, and demonstrates improved outcomes when compared with epidural analgesia in minimally invasive abdominal surgery [18]. However, the analgesic benefits demonstrated with central neuraxial blockade do not seem to outweigh the inherent risks, and spinal anaesthesia in the context of minimally invasive abdominal surgery may be perceived by some as unnecessary [19]. Thoracic paravertebral blocks have recently shown promise and an increase in clinical uptake due to the growing use of ultrasound-guided regional anaesthesia [20]. Their role in peri-operative analgesic strategies in breast and thoracic surgery are well established, but the efficacy of thoracic paravertebral blocks has yet to convincingly justify their use in abdominal surgery due to a limited evidence base [21]. The other, perhaps more pertinent barrier, is that ultrasound-guided thoracic paravertebral block is viewed as an advanced regional anaesthetic technique, being technically challenging, time consuming, and carrying with it not insignificant risks such as pneumothorax. As modern regional anaesthesia is now highly subspecialised, and indepth teaching and training are required for competence in each block [22], it is becoming more difficult to deliver training in techniques such as ultrasound-guided thoracic paravertebral block within training programs that have an unpredictable clinical workload [23]. Should we, therefore, limit the scope of blocks taught to anaesthetists who have not completed a regional anaesthesia fellowship [24]? If the answer is yes, this may lead to patients being denied opiate-sparing analgesia as their anaesthetist lacks competence for performing more advanced blocks. The other option is the quest for simpler alternatives to these more advanced techniques. The rise of the fascial plane block Significant efforts have been made in recent years to identify such alternative regional anaesthetic strategies for abdominal surgery, and the recent interest in fascial plane blocks in this clinical setting may signal a paradigm shift by displacing thoracic paravertebral blocks [25, 26]. With the first descriptions of the landmark guided transversus abdominal plane (TAP) block, we witnessed the birth of the fascial plane, or myofascial plane block and an exciting new avenue in clinical research (Fig. 1). Transversus abdominal plane blocks have been embraced by both regional and non-regional anaesthetists alike in recent years. As a fascial plane block, it is a relatively easy technique to perform for those who do not utilise an ultrasound probe as part of their daily routine, and significant risks, such as intraperitoneal injection or injury to intraabdominal viscera, are rare [27]. However, there are a multitude of approaches [28], some requiring four separate injections [29], producing variable endpoints of analgesia. Furthermore, despite showing early promise, the evidence for the true efficacy of TAP blocks is increasingly being questioned [30, 31], as eloquently discussed by Chin et al. with particular reference to ventral hernia surgery [1]. These deficiencies in the TAP block were recognised, leading to the development of the quadratus lumborum block. This is a fascial plane block that has been proposed 2017 The Association of Anaesthetists of Great Britain and Ireland 435

3 Number of publications for abdominal surgery, achieving analgesia by supposed spread of local anaesthetic to the thoracic paravertebral space. Yet again, a number of different ultrasoundguided approaches have been investigated with a lack of clarity on the true mechanism of action [32]. Moreover, the quadratus lumborum block is also seen as a time-consuming, advanced block that is technically challenging to perform, and has made little impact on the practice of non-regional anaesthetists in their care of patients having abdominal surgery. Perhaps the time has come to explore less invasive, safer and quicker alternatives to current standards of analgesia that are accessible to anaesthetists whose daily practice does not involve wielding an ultrasound probe? We need, something plain (plane!) and simple that can be performed by many and is therefore accessible to all patients Year Figure 1 The number of publications per annum over the last 10 years relating to different blocks. Blue, PECS block; orange, quadratus lumborum block; grey, serratus plane block; yellow, transversus abdominis plane block. Does the ESP block fit the bill for abdominal surgery? Can it work hand in hand with multimodal analgesia strategies and still respect the tenets of ERAS? Part of the appeal of the ESP block could be that it is gaining indirect access to the paravertebral space and providing analgesia without the potential for needle-pleura interaction and consequent risk of pneumothorax. Chin et al. [1] are not the only ones to have caught onto this idea, with other investigators heading back to the cadaver lab with their ultrasound machines and methylene blue [33]. The sole aims for the practitioner are to identify erector spinae muscle above transverse process, direct the needle to the bone and inject local anaesthetic. This is conceivably something that could also be performed relatively simply in the obese patient, making it an attractive option. The unknowns of the ESP block It is early days to recommend a change in practice based on a case series of four patients, and we would exercise a cautious approach when interpreting the data presented by Chin et al. [1]. For example, the use of non-standardised additives and the variable local anaesthetic doses, often at the upper dose limit, and the variable spread of local anaesthetic in the cadaveric data, leaves question marks regarding consistency of the ESP block. It could also be argued that the doses of peri-operative opiate that some of the patients in this study were exposed to were not insignificant. Additionally, a large number of ESP blocks will need to be reported on in order to truly assess the safety and efficacy of this technique. Finally, the data reported here is non-comparative, and does not tell us if this block is better than no block at all. It would be most useful to have a comparison to alternative techniques, including surgical infiltration of local anaesthetic, and this will need well-designed randomised controlled trials to be performed. What is the optimal analgesic strategy for minimally invasive abdominal surgery? We suggest it is the technique that can be performed by all, quickly and simply, is reliable and consistent, is opiatesparing, and has minimal complications we find it exciting that the ESP block could potentially be the answer. What remains is hard proof for the clinical efficacy and safety of this block, followed by a demonstration of the uptake of it in the The Association of Anaesthetists of Great Britain and Ireland

4 Anaesthesia 2017, 72, hands of non-regional anaesthetists. The lack of meaningful outcome benefits of TAP blocks serves as a lesson to incorporate new regional anaesthetic techniques with caution; only time will tell if the ESP block can fulfil its true potential. Acknowledgements KE is the trainee fellow with the Anaesthesia editorial board. AP is a board member of Regional Anaesthesia UK and academic lead of the London Society of Regional Anaesthesia. No external funding or other competing interests declared. K. El-Boghdadly Specialist Registrar elboghdadly@gmail.com A. Pawa Consultant Department of Anaesthetics, Guy s and St Thomas NHS Foundation Trust London, UK Keywords: enhanced recovery; nerve block; regional analgesia; surgical outcomes References 1. Chin KJ, Adhikary S, Sarwani N, Forero M. The analgesic efficacy of pre-operative bilateral erector spinae plane (ESP) blocks in patients having ventral hernia repair. Anaesthesia 2017; 72: Kehlet H, Dahl JB. Anaesthesia, surgery, and challenges in postoperative recovery. Lancet 2003; 362: Kehlet H, Wilmore DW. Evidence-based surgical care and the evolution of fasttrack surgery. Annals of Surgery 2008; 248: Singh PM, Panwar R, Borle A, et al. Efficiency and safety effects of applying ERAS protocols to bariatric surgery: a systematic review with meta-analysis and trial sequential analysis of evidence. Obesity Surgery 2017; 27: Moore JA, Conway DH, Thomas N, Cummings D, Atkinson D. Impact of a peri-operative quality improvement programme on postoperative pulmonary complications. Anaesthesia 2017; 72: Nelson G, Kiyang LN, Crumley ET, et al. Implementation of enhanced recovery after surgery (ERAS) across a provincial healthcare system: the ERAS Alberta colorectal surgery experience. World Journal of Surgery 2016; 40: Levy N, Mills P, Mythen M. Is the pursuit of DREAMing (drinking, eating and mobilising) the ultimate goal of anaesthesia? Anaesthesia 2016; 71: Power I, McCormack JG, Myles PS. Regional anaesthesia and pain management. Anaesthesia 2010; 65: Reddi D. Preventing chronic postoperative pain. Anaesthesia 2016; 71: Xu YJ, Li SY, Cheng Q, et al. Effects of anaesthesia on proliferation, invasion and apoptosis of LoVo colon cancer cells in vitro. Anaesthesia 2016; 71: Ciechanowicz SJ, Ma D. Anaesthesia for oncological surgery Can it really influence cancer recurrence? Anaesthesia 2016; 71: Wu CL, Cohen SR, Richman JM, et al. Efficacy of postoperative patient-controlled and continuous infusion epidural analgesia versus intravenous patient-controlled analgesia with opioids: a meta-analysis. Anesthesiology 2005; 103: Basse L, Raskov HH, Hjort Jakobsen D, et al. Accelerated postoperative recovery programme after colonic resection improves physical performance, pulmonary function and body composition. British Journal of Surgery 2002; 89: Freise H, Van Aken HK. Risks and benefits of thoracic epidural anaesthesia. British Journal of Anaesthesia 2011; 107: Hughes MJ, Ventham NT, McNally S, Harrison E, Wigmore S. Analgesia after open abdominal surgery in the setting of enhanced recovery surgery a systematic review and meta-analysis. Journal of the American Medical Association Surgery 2014; 149: Halabi WJ, Kang CY, Nguyen VQ, et al. Epidural analgesia in laparoscopic colorectal surgery. Journal of the American Medical Association Surgery 2014; 149: H ubner M, Blanc C, Roulin D, Winiker M, Gander S, Demartines N. Randomized clinical trial on epidural versus patient-controlled analgesia for laparoscopic colorectal surgery within an enhanced recovery pathway. Annals of Surgery 2015; 261: Levy BF, Scott MJ, Fawcett W, Fry C, Rockall TA. Randomized clinical trial of epidural, spinal or patient-controlled analgesia for patients undergoing laparoscopic colorectal surgery. British Journal of Surgery 2011; 98: Joshi GP, Bonnet F, Kehlet H. Evidencebased postoperative pain management after laparoscopic colorectal surgery. Colorectal Disease 2013; 15: Krediet AC, Moayeri N, van Geffen GJ, et al. Different approaches to ultrasoundguided thoracic paravertebral block. Anesthesiology 2015; 123: El-Boghdadly K, Madjdpour C, Chin KJ. Thoracic paravertebral blocks in abdominal surgery a systematic review of randomized controlled trials. British Journal of Anaesthesia 2016; 117: McCartney CJL, Mariano ER. Education in ultrasound-guided regional anesthesia: lots of learning left to do. Regional Anesthesia and Pain Medicine 2016; 41: Chuan A, Graham PL, Wong DM, et al. Design and validation of the regional anaesthesia procedural skills assessment tool. Anaesthesia 2015; 70: Chuan A, Lim YC, Aneja H, et al. A randomised controlled trial comparing meat-based with human cadaveric models for teaching ultrasound-guided regional anaesthesia. Anaesthesia 2016; 71: Bashandy GMN, Abbas DN. Pectoral nerves I and II blocks in multimodal analgesia for breast cancer surgery a randomized clinical trial. Regional Anesthesia and Pain Medicine 2015; 40: Kulhari S, Bharti N, Bala I, Arora S, Singh G. Efficacy of pectoral nerve block versus thoracic paravertebral block for postoperative analgesia after radical mastectomy : a randomized controlled trial. British Journal of Anaesthesia 2016; 117: Taylor R Jr, Pergolizzi JV, Sinclair A, et al. Transversus abdominis block: clinical uses, side effects, and future perspectives. Pain Practitioner 2013; 13: Carney J, Finnerty O, Rauf J, Bergin D, Laffey JG, Mc Donnell JG. Studies on the spread of local anaesthetic solution in transversus abdominis plane blocks. Anaesthesia 2011; 66: The Association of Anaesthetists of Great Britain and Ireland 437

5 29. Niraj G, Kelkar A, Hart E, et al. Comparison of analgesic efficacy of four-quadrant transversus abdominis plane (TAP) block and continuous posterior TAP analgesia with epidural analgesia in patients undergoing laparoscopic colorectal surgery: an open-label, randomised, non-inferiority tri. Anaesthesia 2014; 69: Abdallah FW, Chan VW, Brull R. Transversus abdominis plane block a systematic review. Regional Anesthesia and Pain Medicine 2012; 37: Baeriswyl M, Kirkham KR, Kern C, Albrecht E. The analgesic efficacy of ultrasound-guided transversus abdominis plane block in adult patients: a meta-analysis. Anesthesia and Analgesia 2015; 121: Adhikary SD, El-Boghdadly K, Nasralah Z, Sarwani N, Nixon AM, Chin KJ. A radiologic and anatomic assessment of injectate spread following transmuscular quadratus lumborum block in cadavers. Anaesthesia 2017; 72: Costache I, Sinclair J, Farrash FA, et al. Does paravertebral block require access to the paravertebral space? Anaesthesia 2016; 71: doi: /anae The Association of Anaesthetists of Great Britain and Ireland