Regional anaesthesia for all

There has been recently an explosion of new regional anaesthesia techniques that seem to promise better outcomes for patients undergoing surgery. That said, most anaesthetists will probably never perform a PECS, QLB, BD-TAP, ACB, RLB, RISS, PENG, MICB or TQL block, to name but a few. Fear not, this excellent new editorial from Turbitt, Mariano and El-Boghdadly aims to recalibrate current practice and lists a limited selection of high value, basic blocks. You can hear more about this extremely popular paper, including why the authors wrote it and what they have planned for the future, in the next #TheAnaesthesiaPodcast on the 16th of March. For now, readers might also be interested in this systematic review, meta-analysis and trial sequential analysis of the posterior suprascapular block in shoulder surgery and this meta-analysis of local anaesthetic delivery regimens for peripheral nerve catheters.

This new rapid sequence intubation survey from Zdravkovic et al. is impressive work for several reasons (Fig. 1). Firstly, they recruited over 10,000 anaesthetists from across the world using platforms such as LinkedIn. Secondly, they compared responses with the opinions of recognised international airway management experts. Finally, their results have consequences for clinical practice and a wide range of future research priorities. Will we ever achieve consensus for an area of practice with such wide variations and controversy? Charlesworth and El-Boghdadly argue such aims might be outdated, and the old questions about thiopentone vs. propofol, suxamethonium vs. rocuronium and opioid vs. no opioid are no longer relevant. Perhaps the new PUMA guidelines, expected later this year, will add some much-needed clarity. For now, readers might also be interested in this new multidisciplinary consensus statement on fasting before procedural sedation in adults and children, which we discussed recently in the #NotSoFast TweetChat

Figure 1 Preferences for rapid sequence intubation from respondents from high‐income countries (filled circles), upper middle‐income (diamond), lower middle‐income (triangle) and low‐income (empty circles). The upper three panels (a) are for a hypothetical patient with intestinal obstruction. The lower three panels (b) are for any other rapid sequence intubation indication.

Obstructive sleep apnoea (OSA) is common, with most cases in the peri-operative setting presenting without a formal diagnosis. This new prospective trial from Christensson et al. suggests that partial neuromuscular blockade in patients with OSA inhibits hypoxic ventilatory response, which is restored through full recovery from paralysis. The physiology behind this study and the methods used to investigate the hypothesis are simply fascinating! Thankfully, Raju and Pandit are at hand to explain all this along with the associated clinical context (Fig. 2). 

Figure 2 Schematic for oxygen sensing at type‐1 glomus cell of carotid body. (1) Hypoxia closes background K+ (TASK) channels, which normally permit background leak of K+ outside the cell; K+ is thus retained in the cell, causing depolarisation. (2) Depolarisation opens voltage‐gated Ca2+ channels, leading to Ca2+ influx. (3) This causes fusion of vesicles containing neurotransmitters (NT) with the cell membrane and acetylcholine (ACh; the likely clinically‐relevant neurotransmitter) is released into the synaptic cleft. (4) ACh binds to specific nicotinic receptors (nAChR) causing action potentials in the afferent glossopharyngeal neve, which travel to the respiratory centre. Volatile anaesthetics block the oxygen sensing by TASK channels at step (1). Propofol inhibits glomus cell response by an as yet undefined mechanism (possibly inhibiting voltage‐gated Ca2+ channels at (2); see reference 14). Neuromuscular blockade prevents binding of ACh at nAChR at (4).

Gastric ultrasound is becoming increasingly popular in the peri-operative setting, but it might also have a role in the critical care unit. This new prospective multicentre cohort study from Bouvet et al. suggests that gastric suctioning in mechanically ventilated patients is not a reliable tool for monitoring residual gastric volume. The question is, can gastric ultrasound be used in this setting to reduce the risk of regurgitation, vomiting and ventilator-associated pneumonia? Last year, we were delighted to publish our international consensus statement on the use of uterotonic agents during caesarean section. This highlighted the potential for a reduced dose of carbetocin of < 100 μg for low-risk women. This month, Drew et al. find that the ED90 for carbetocin in obese women with a BMI ≥ 40 kg.m-2 is less than this, and even less still for women with a BMI < 40 kg-2 (Figure 3). Their methods are an excellent example of how a dose-finding study can be conducted using a biased coin up-and-down sequential randomised allocation scheme.

Figure 3 Sequence of doses administered and subsequent response. Success – filled circle; failure – open circle.

Elsewhere we have a study of the Quantra® point‐of‐care haemostasis analyser during urgent cardiac surgeryan observational study of the effects of tracheal intubation and tracheal tube position on regional lung ventilationa study of the discrimination of quick Paediatric Early Warning Scores in the pre‐hospital setting; and a retrospective study of short‐term safety and effectiveness of sugammadex for surgical patients with end‐stage renal disease

Finally, we are delighted to announce that Anaesthesia Reports is now indexed on the PubMed database! Anaesthesia Reports represents the next generation of peer-reviewed journals that accepts case reports, videos, images and educational articles from authors anywhere in the world. Regardless of author background or subject area, it offers a cutting-edge platform for authors, readers and patients. PubMed listing is a major step forward, as it reflects the quality, legitimacy and scientific value of the journal. You can catch up with the most recent issue by reading this excellent summary from the editorial team.

#ReportsComeOfAge!

Mike Charlesworth and Andrew Klein

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