This Week in Anesthesiology — Aug 24, 2026

Welcome to This Week in Anesthesiology. This week we're covering 10 notable papers spanning intraoperative haemodynamic management, the ongoing puzzle of GLP-1 receptor agonists and gastric emptying, and regional anaesthesia and analgesic strategy — including a hard look at the quality of the evidence we build guidelines on. Let's dive in.

We start with blood pressure, where two papers together should simplify how you think about intraoperative hypotension. In Anesthesiology, Florax and colleagues ran a single-centre, blinded randomised trial in adults having moderate- or high-risk elective non-cardiac surgery with continuous arterial pressure monitoring, asking whether a plain mean arterial pressure alarm set at 72 millimetres of mercury is non-inferior to the proprietary Hypotension Prediction Index alarm at its default threshold [1]. In 143 patients analysed, the area under the 65 millimetre threshold — the standard measure of hypotensive burden — was essentially identical in the two groups, a median of under four millimetre-minutes either way, and the non-inferiority margin was met comfortably. There were no differences in secondary haemodynamic measures, alarm behaviour, acute kidney or myocardial injury, mortality, length of stay, or vasopressor and fluid use. The implication is direct: the predictive index's advantage over simply watching the pressure closely may be largely explained by its correlation with mean arterial pressure itself, and a 72 millimetre alarm on any monitor is a pragmatic, no-cost alternative. Sitting alongside this, the British Journal of Anaesthesia published an editorial from Sessler with the single-word title "Quanto?" — how much? — discussing a meta-analysis of nine randomised trials in more than fourteen thousand patients comparing routine blood pressure management with deliberately higher targets [7]. The pooled result on mortality was neutral. Read together with the alarm trial, the message for the practising anaesthetist is that pressures at or above 65 millimetres appear generally safe, even in older hypertensive patients with cardiovascular risk factors, and chasing higher targets has not been shown to reduce organ injury or death. The energy is better spent avoiding sustained low pressure than buying algorithms to predict it.

Next, two papers in the Canadian Journal of Anesthesia tackle the question that has dominated preoperative clinics for two years: what to do about glucagon-like peptide-1 receptor agonists and retained gastric contents. Wilson and colleagues report a prospective observational study of 256 patients scheduled for elective endoscopy involving stomach visualisation [2]. Patients on these drugs were instructed to hold the medication for one week and to take only clear liquids for the 24 hours beforehand; controls simply fasted for eight hours. Retained gastric contents — solid material, or liquid above a weight-based threshold — occurred in about 8 percent of the drug group and about 6 percent of controls, a difference that was not statistically significant. There were no aspiration events, no aborted procedures, and no relevant conversions to general anaesthesia. Notably, endoscopists were more likely to report subjective concern about gastric contents in the drug group, roughly one in five compared with about one in fourteen — a reminder that perceived risk and measured risk can diverge. Complementing that, Mendez-Pino and colleagues looked retrospectively at 337 patients across five hospitals who were taking or had recently stopped one of these agents before upper endoscopy [3]. Overall prevalence of retained contents was about 8 percent, similar to the prospective study. In adjusted analysis, fasting from solids for longer than 15 hours was associated with roughly a two-thirds reduction in the odds of retained contents. Fasting duration for liquids, the presence of diabetes, and total duration of drug therapy showed no significant association, and stopping the drug less than seven days beforehand was not significantly associated with retained contents, though the estimate was imprecise. Taken together, these two datasets suggest that with a deliberate preparation strategy — extended clear liquids, a longer solid fast, and drug interruption — retained gastric contents in this population sit in single digits and look much like the background rate. That supports a preparation-based approach rather than reflexive cancellation, while acknowledging both studies are modest in size and neither was powered for aspiration itself.

On the regional anaesthesia front, three papers ask not whether blocks work but which ones, for whom, and why. Anaesthesia published a narrative review from Tolson, Sotiriou and Pawa synthesising 63 studies on regional anaesthesia for breast surgery [5]. Their conclusion is anatomical rather than fashionable: every block outperformed local anaesthetic infiltration, newer paraspinal techniques including the erector spinae plane block have demonstrated analgesic efficacy, but the thoracic paravertebral block remains the most reliable option. They map the territories — anterolateral chest wall blocks for the lateral cutaneous branches of the intercostal nerves, the interpectoral block as the only chest wall approach covering the pectoral nerves, the superficial parasternal intercostal plane block for the medial breast — and argue for tailoring the technique to the specific operation rather than defaulting to one block. That pairs with a retrospective cohort in the Journal of Clinical Anesthesia from Tokocin and colleagues, looking beyond acute analgesia to function [9]. Among 147 women aged 65 and over having modified radical mastectomy, those who received combined pectoserratus and serratus anterior plane blocks had substantially better shoulder disability scores at six months — roughly eight points versus nineteen on the QuickDASH — and persistent shoulder stiffness in about 42 percent compared with about 70 percent without regional anaesthesia. Regional blockade emerged as an independent protective factor, cutting the odds of persistent stiffness by roughly 70 percent. Balance that against the fact that the Constant-Murley score showed no difference between groups, the range-of-motion differences were a few degrees, and the design is retrospective, so causation cannot be claimed. And the British Journal of Anaesthesia offers the sceptical counterweight from Coppens and colleagues, whose editorial on fascial plane blocks five years on argues that despite thousands of publications, mechanisms, anatomy, timing, dosing, safety and patient selection remain unresolved [10]. Their framing is worth carrying into practice: the task for the next decade is not inventing more blocks but working out which ones work and in whom.

Two papers address systemic analgesic and anaesthetic adjuncts, and both should temper enthusiasm. In the Journal of Clinical Anesthesia, Liu and colleagues randomised 98 patients having unilateral total knee arthroplasty to an opioid-sparing regimen built on esketamine and dexmedetomidine, or conventional opioid-based anaesthesia, with both groups receiving a femoral nerve block and identical postoperative multimodal analgesia [4]. Quality of recovery at 24 hours was about five points higher in the opioid-sparing group and the advantage persisted at 48 hours, with less nausea and vomiting, lower C-reactive protein, and a small advantage in Oxford Knee Score at one month. Crucially, the authors themselves note that the recovery score difference did not reach the minimal clinically important difference, so the clinical relevance remains uncertain. Meanwhile, in the British Journal of Anaesthesia, Talmy and colleagues used a large United States research network to test the preclinical suggestion that ketamine might have antitumour effects, propensity-matching nearly thirty thousand pairs of patients having major solid tumour cancer surgery [8]. Ketamine on the day of surgery was not associated with lower three-year mortality — around 17 percent in each group — and there was no difference at five years, across cancer types and sensitivity analyses. An exploratory analysis did find a lower risk of a composite of surrogate markers of disease progression, but that is hypothesis-generating only. Use ketamine for analgesia, not for oncological hope. Finally, and fittingly, Joshi, Lobo and Kehlet argue in the British Journal of Anaesthesia that most systematic reviews and network meta-analyses of perioperative analgesic interventions carry critical flaws — loose inclusion criteria, uncritical quality assessment, clinical heterogeneity, absent basic analgesics, static rather than dynamic pain scores, fragility and spin — and that sophisticated statistics cannot rescue heterogeneous or poor-quality trials [6]. Guidelines built on such syntheses may be inaccurate. It is a useful lens for every paper in this episode.

If you only have time for one paper this week, make it the Anesthesiology randomised trial comparing a simple mean arterial pressure alarm at 72 millimetres with the Hypotension Prediction Index [1]. It is a rare trial that can change practice by removing technology rather than adding it, and every anaesthetist with a monitor and an alarm limit can act on it tomorrow.

Here are the key takeaways from this week in Anesthesiology. First, a mean arterial pressure alarm set at 72 millimetres was non-inferior to the Hypotension Prediction Index for preventing intraoperative hypotension, and targeting pressures above the conventional 65 millimetre threshold has not reduced mortality in pooled randomised data. Second, in patients on GLP-1 receptor agonists, a structured preparation of extended clear liquids and a longer solid fast was associated with retained gastric contents in only around 8 percent, similar to controls, supporting preparation over cancellation. Third, in breast surgery the thoracic paravertebral block remains the most reliable technique, all blocks beat local infiltration, and chest wall blocks may carry longer-term functional benefit — though that evidence is retrospective. Fourth, an opioid-sparing regimen using esketamine and dexmedetomidine improved recovery scores after knee arthroplasty but not by a clinically important margin, and perioperative ketamine showed no survival benefit after major cancer surgery. And fifth, read meta-analyses and the guidelines built on them with a critical eye — statistical sophistication does not fix heterogeneous or low-quality trials.

That's your roundup for This Week in Anesthesiology. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.

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This is an automated summary generated by artificial intelligence, which can make mistakes. Always review the original source materials.