Kariem El-Boghdadly

The erector spinae plane block: plane and simple

guided peripheral nerve blocks: what are the benefits? Acta Anaesthesiologica Scandinavica 2008; 52: 727–37. 4. 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: CD006459. 5. Munirama S, McLeod G. A systematic review and meta-analysis of ultrasound versus electrical stimulation for peripheral nerve location and blockade. Anaesthesia 2015; 70: 1084–91. 6. Halsted WS. Practical comments on the use and abuse of cocaine. New York Medical Journal 1885; 42: 294–5. 7. Chandra A, Eisma R, Felts P, Munirama S, McLeod G. The feasibility of microultrasound as a tool to image peripheral nerves. Anaesthesia 2017; 72: 190–6. 8. Bigeleisen PE. Nerve puncture and apparent intraneural injection during ultrasound-guided axillary block does not invariably result in neurologic injury. Anesthesiology 2006; 105: 779–83. 9. Bigeleisen PE, Moayeri N, Groen GJ. Extraneural versus intraneural stimulation thresholds during ultrasoundguided supraclavicular block. Anesthesiology 2009; 110: 1235–43. 10. Robards C, Hadzic A, Somasundaram L, et al. Intraneural injection with lowcurrent stimulation during popliteal sciatic nerve block. Anesthesia and Analgesia 2009; 109: 673–7. 11. 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: 1281–4. 12. 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: 393–9. 13. Liguori GA. Complications of regional anesthesia: nerve injury and peripheral neural blockade. Journal of Neurosurgical Anesthesiology 2004; 16: 84–6. 14. 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: 479–90. 15. Brull R, McCartney CJL, Chan VWS, ElBeheiry H. Neurological complications after regional anesthesia: contemporary estimates of risk. Anesthesia and Analgesia 2007; 104: 965–74.

A prospective cohort study of awake fibreoptic intubation practice at a tertiary centre

Contemporary data are lacking for procedural practice, training provision and outcomes for awake fibreoptic intubation in the UK. We performed a prospective cohort study of awake fibreoptic intubations at a tertiary centre to assess current practice. Data from 600 elective or emergency awake fibreoptic intubations were collected to include information on patient and operator demographics, technical performance and complications. This comprised 1.71% of patients presenting for surgery requiring a general anaesthetic, with the majority occurring in patients presenting for head and neck surgery. The most common indication was reduced mouth opening (26.8%), followed by previous airway surgery or head and neck radiotherapy (22.5% each). Only five awake fibreoptic intubations were performed with no sedation, but the most common sedative technique was combined target‐controlled infusions of remifentanil and propofol. Oxygenation was achieved with high‐flow, heated and humidified oxygen via nasal cannula in 49.0% of patients. Most operators had performed awake fibreoptic intubation more than 20 times previously, but trainees were the primary operator in 78.6% of awake fibreoptic intubations, of which 86.8% were directly supervised by a consultant. The failure rate was 1.0%, and 11.0% of awake fibreoptic intubations were complicated, most commonly by multiple attempts (4.2%), over‐sedation (2.2%) or desaturation (1.5%). The only significant association with complications was the number of previous awake fibreoptic intubations performed, with fewer complications occurring in the hands of operators with more awake fibreoptic intubation experience. Our data demonstrate that awake fibreoptic intubation is a safe procedure with a high success rate. Institutional awake fibreoptic intubation training can both develop and maintain trainee competence in performing awake fibreoptic intubation, with a similar incidence of complications and success compared with consultants.

Intra-oral ignition of monopolar diathermy during transnasal humidified rapid-insufflation ventilatory exchange (THRIVE)

We present the case of unanticipated airway ignition during hard palate biopsy. Transnasal humidified rapid‐insufflation ventilatory exchange (THRIVE) and monopolar diathermy were utilised for the procedure, during which an arc arose from the diathermy tip to a titanium implant, causing a brief ignition on the monopolar diathermy grip. This case highlights the need for maintained awareness of fire risk when using diathermy in the presence of THRIVE during airway surgery.

Combined thoracic paravertebral and pectoral nerve blocks for breast surgery under sedation: a prospective observational case series

Avoidance of general anaesthesia for breast surgery may be because of clinical reasons or patient choice. There is emerging evidence that the use of regional anaesthesia and the avoidance of volatile anaesthetics and opioid analgesia may have beneficial effects on oncological outcomes. We conducted a prospective observational case series of 16 breast cancer surgeries performed under thoracic paravertebral plus pectoral nerve block with propofol sedation to demonstrate feasibility of technique, patient acceptability and surgeon satisfaction. Fifteen out of 16 cases were successfully completed under sedation and regional anaesthesia, with one conversion to general anaesthesia. Eleven out of 16 cases required low‐dose intra‐operative opioid analgesia. Out of the 15 surgical procedures completed under regional anaesthesia with sedation, all patients experienced either no or minimal intra‐operative pain, and all would choose this anaesthetic technique again. Surgeon‐reported operating conditions were ‘indistinguishable from general anaesthesia’ in most cases, and surgeons were ‘extremely satisfied’ or ‘satisfied’ with the technique after every procedure. Combined thoracic paravertebral plus pectoral nerve block with intra‐operative sedation is a feasible technique for breast surgery.

In reply: Proper use and interpretation of diaphragmatic ultrasonography

To the Editor, We are grateful to Dr. Sondekoppam et al. for their dialogue relating to our recently proposed method that aims to simplify diaphragmatic ultrasonography for detecting phrenic nerve palsy by tracking gross pleural movement. Although promising in our preliminary experience, we caution that this method must undergo validation against well-established diaphragmatic excursion measurements. Similar to the ABCDE approach with a sniff test, our method also interrogates the diaphragmatic zone of apposition and the adjacent pleura. Unlike the ABCDE approach, however, which measures the change in diaphragmatic muscle thickness on Band M-mode sonograms, we simply measure a change in the pleural line position on the skin surface from full expiration to full inspiration. Another distinction we emphasize is recognition of the sonographic appearances of the rib, pleural line, diaphragm, and visceral organs (liver or spleen) as critical for identifying the direction of probe movement, independent of the initial probe position. For example, if the initial scan is too caudal (i.e. showing the diaphragm and spleen), the next logical step is to move the probe cephalad, and vice versa. Our scanning approach is therefore based on ‘‘sonoanatomical’’ observations to identify an ‘‘ideal site’’ to start scanning, and not a palatable mnemonic aid (ABCDE approach). The value of our technique lies in assessing pleural movement before and after performing a block to detect diaphragmatic paresis. Thus, patients act as their own controls, allowing comparison of changes in excursion. This approach should theoretically reduce the risk of false negatives reported with other techniques, including studies cited by Sondekoppam et al. Diaphragmatic thickness and excursion measurements are well-established, validated methods for assessing diaphragmatic function in spontaneously ventilating patients. Thus, the two recently described methods are not entirely ‘‘new’’ as both represent simplified versions of existing methods. Sondekoppam et al. questioned our assessment of diaphragmatic function based on the extent of pleural movement. Although we make no claim that lung volume assessment is accurate with our method, displacement of the diaphragm at the level of the zone of apposition correlates well with contraction, as elegantly demonstrated in the figure provided by Naik et al. Hence, regional anesthesia studies assessing diaphragmatic paresis routinely use this concept to diagnose phrenic nerve palsy. Additionally, although tidal volume breathing utilizes multiple muscle groups, the diaphragm is the primary driver. Thus, the well-known phenomenon of diaphragmatic displacement translates to movement of the adherent pleura, particularly at the caudal extremes – the ultimate goal of diaphragmatic contraction. In the presence of either acute or chronic complete paralysis, excursion might be absent, and partial paralysis might be accompanied by reduced excursion. The latter, however, may be associated with some diaphragmatic (ergo pleural) movement, as might have been demonstrated by the figure provided by Sondekoppam et al. The same principles hold true for diaphragmatic thickness assessment. Indeed, a minimal change in muscular K. El-Boghdadly, MBBS (&) Guy’s & St Thomas’ NHS Foundation Trust, London, UK e-mail: elboghdadly@gmail.com

Update on Ultrasound for Truncal Blocks: Interpret Cautiously.

Daring may be defined as “venturesomely bold in action or thought.”Discourse may be defined as a “formal and orderly and usually extended expression of thought on a subject.” Thus, the desire of the editors is to have a place where discussions of importance to our subspecialties can be discussed openly and boldly, potentially even at some risk, to plot future strategies for research or to confront areas of social or political importance as related to the practice of regional anesthesia and pain medicine. On the basis of the information presented, our paper fits the mold of a “Daring Discourse.” In retrospect, however, given the limitations of our work, perhaps a more appropriate title would have been “Adductor Canal Block Versus Femoral Canal Block for Total Knee Arthroplasty: What Does the Evidence Suggest?” Second, we agree with the concern regarding the PRISMA guidelines. Adhering to the PRISMA guidelines certainly helps improve the reporting quality of all metaanalyses. Once again, however, our paper was published as a “Daring Discourse.” Finally, although this does not affect the results of the review, we acknowledge the noted error in the reference list. The study by Jaeger et al that was included in the analysis was incorrectly cited. The correct reference is listed in the reference list. Similarly, the line in the discussion which began with “Recently, concern has been raised about the RCT conducted by Jaeger et al...” should be cited as using this same reference, not the healthy volunteers study conducted by Jaeger et al. Again, we thank Drs Smith and Barrington for reviewing our work and for their insights.

Images in Anesthesiology: Gastric Ultrasound.

Images in Anesthesiology: Gastric Ultrasound Kariem El-Boghdadly;Richelle Kruisselbrink;Vincent W. Chan;Anahi Perlas; Anesthesiology

Regional anaesthesia as the principle technique in breast surgery - a reply

anaesthetic technique on the surgical field or did the omission of GA manifest in patient movement, coughing or inadequate relaxation? We suspect that patients would attach significance to this finding when contemplating this technique vs. GA in cancer surgery. We question whether all patients would indeed choose the technique again if informed of this, particularly as all but two of the cohort were not considered high risk for GA. In addition, breast cancer surgery is a highly emotive and anxiety-provoking proposition and we wonder whether a better reflection of patient acceptability is suggested by the recruitment of only 16 patients over a period exceeding a year. Another limitation is the large doses of local anaesthetic used, despite which 11 patients still required intravenous (i.v.) fentanyl for intra-operative discomfort (and one converted to GA after a failed modification of the technique). Pawa et al.’s description details the administration of 500 mg lidocaine (with adrenaline) and 125 mg of levobupivacaine; this would arguably exceed the maximal recommended dose in a patient with an actual body weight of 130 kg, yet the mean (SD) for their cohort was 73 (17) kg. The technique is described as being “. . . modified accordingly for patients of lower weight” but we would be grateful for clarification of how, as the authors did not specify further. As described, however, is that multiple distinct nerves may provide important innervation to operative sites involving the breast and axilla and this may be complicated by significant interpatient variation and contralateral innervation across the midline. This illustrates the difficulty of relying principally on a regional anaesthetic technique for such surgery and that contingency options of further surgical local anaesthetic infiltration, whilst remaining within local anaesthetic dose limits, and/or GA conversion need to be anticipated. Within our institution, we encourage the use of paravertebral and/or myofascial plane blocks to achieve the fundamental stated aims: improve analgesia; opioid spare; enhance recovery; and as an alternative to GA in those that are genuinely high risk. Volatile avoidance is facilitated by a preference for total i.v. anaesthesia. We anticipate that the overwhelming majority of patients will continue to express a preference for GA as the principle anaesthetic technique.

Evidence Basis for Regional Anesthesia in Ambulatory Arthroscopic Knee Surgery and Anterior Cruciate Ligament Reconstruction: Part II: Adductor Canal Nerve Block-A Systematic Review and Meta-analysis.

BACKGROUND: Adductor canal block (ACB) has emerged as an effective analgesic regional technique for major knee surgeries in the last decade. Its motor-sparing properties make it particularly attractive for ambulatory knee surgery, but evidence supporting its use in ambulatory arthroscopic knee surgery is conflicting. This systematic review and meta-analysis evaluates the analgesic effects of ACB for ambulatory arthroscopic knee surgeries. METHODS: We conducted a comprehensive search of electronic databases for randomized controlled trials examining the analgesic effects of ACB compared to control or any other analgesic modality. Both minor arthroscopic and anterior cruciate ligament reconstruction (ACLR) surgeries were considered. Rest and dynamic pain scores, opioid consumption, opioid-related adverse effects, time to first analgesic request, patient satisfaction, quadriceps strength, and block-related complications were evaluated. Data were pooled using random-effects modeling. RESULTS: Our search yielded 10 randomized controlled trials comparing ACB with placebo or femoral nerve block (FNB); these were subgrouped according to the type of knee surgery. For minor knee arthroscopic surgery, ACB provided reduced postoperative resting pain scores by a mean difference (95% confidence interval) of −1.46 cm (−2.03 to −0.90) (P < .00001), −0.51 cm (−0.92 to −0.10) (P = .02), and −0.48 cm (−0.93 to −0.04) (P = .03) at 0, 6, and 8 hours, respectively, compared to control. Dynamic pain scores were reduced by a mean difference (95% confidence interval) of −1.50 cm (−2.10 to −0.90) (P < .00001), −0.50 cm (−0.95 to −0.04) (P = .03), and −0.59 cm (−1.12 to −0.05) (P = .03) at 0, 6, and 8 hours, respectively, compared to control. ACB also reduced the cumulative 24-hour oral morphine equivalent consumption by −7.41 mg (−14.75 to −0.08) (P = .05) compared to control. For ACLR surgery, ACB did not provide any analgesic benefits and did not improve any of the examined outcomes, compared to control. ACB was also not different from FNB for these outcomes. CONCLUSIONS: After minor ambulatory arthroscopic knee surgery, ACB provides modest analgesic benefits, including improved relief for rest pain, and reduced opioid consumption for up to 8 and 24 hours, respectively. The analgesic benefits of ACB are not different from placebo or FNB after ambulatory ACLR, suggesting a limited role of both blocks in this procedure. Paucity of trials dictates cautious interpretation of these findings. Future studies are needed to determine the role of ACB in the setting of local anesthetic instillation and/or graft donor-site analgesia.

Current practice for awake fibreoptic intubation – asking the right questions

We would like to thank Drs. Murphy and Howes for their thoughtful editorial, which accompanied our recent study of awake fibreoptic intubation (AFOI) practice [1, 2], and for recognising the training opportunities that our institution provides. However, rather than alluding to unanswered questions in our data, we are concerned that they have applied conjecture and inference to ask the wrong questions about AFOI. Murphy and Howes assert that ‘placing particular emphasis on any individual component . . . risks losing sight of the bigger picture’. Just as pilots emphasise training on the most critical phases of flight, so too must clinicians. Efforts must be made to train for complex, procedural skills as well as considering the important, but non-specific, ‘bigger picture’. The question is – how can we excel at all components of the airway management pathway? The simple answer is self-evident in our data: training. Murphy and Howes cite an editorial [3] written by one of our authors. Our prospective study (rather than audit, as there are no accepted standards) has demonstrated that AFOI is associated with low morbidity and a high success rate, particularly when appropriate training is undertaken. Although we do not state that AFOI should be the ‘gold standard’, our data clearly highlights that AFOI has a valuable role to play in the management of the difficult airway. Had Drs. Murphy and Howes put Ahmad and Bailey’s editorial into context [3], they would have understood that training is recommended for AFOI, and when not undertaken, AFOI should be considered a specialist skill. Performed by appropriately trained and competent clinicians, the utility of a technique that has been part of anaesthetic practice for 50 years is difficult to refute. The question here, then, is: who should train in AFOI? We thank the authors for contextualising our prospective data with retrospective results collected in the USA [4] and Canada [5]. Retrospective data points can be under-reported, and the low complication rates reported by Joseph et al. [4] could be an inaccurate representation of their true incidence. Moreover, the comparable complication rates provided by Law et al. [5] might also be underreported. It would be interesting to know what prospective data from North America shows. Comparing our results with data from unsedated, healthy course delegates (a self-selected group of subjects) is misleading [6]. The immediate complication rate in healthy volunteers was greater than we found in comorbid patients with complex airway pathology (19.5% vs. 11% respectively), and so the co-administration of sedation does not necessarily correlate with increased risk. Interestingly, the Difficult Airway Society has recently commissioned national guidelines on the performance of AFOI. Whether sedation will be recommended as standard practice remains to be seen. The question that needs answering here is: does sedation increase or decrease the safety of performing AFOI? We agree that there is insufficient evidence recommending highflow nasal oxygen (HFNO) for all AFOIs. Murphy and Howes infer our data do not demonstrate that