Weekly Anesthesiology Research Analysis
This week’s anesthesiology literature blends mechanistic neuroscience, pragmatic perioperative trials, and procedure-focused meta-analyses. A mechanistic study identified orexin-driven nucleus-accumbens circuits that control emergence from isoflurane, offering a potential molecular target for modulating arousal. Randomized trials highlighted practical advances — a stellate ganglion block preserved hemodialysis arteriovenous fistula patency and a motor-sparing PENG+LFCN regional technique improve
Summary
This week’s anesthesiology literature blends mechanistic neuroscience, pragmatic perioperative trials, and procedure-focused meta-analyses. A mechanistic study identified orexin-driven nucleus-accumbens circuits that control emergence from isoflurane, offering a potential molecular target for modulating arousal. Randomized trials highlighted practical advances — a stellate ganglion block preserved hemodialysis arteriovenous fistula patency and a motor-sparing PENG+LFCN regional technique improved analgesia after hip arthroplasty. Guideline and large-cohort works emphasize implementable changes: restrictive platelet transfusion thresholds and adoption of device/policy changes (e.g., videolaryngoscopy, CDS ventilation) to improve safety and efficiency.
Selected Articles
1. Orexin signalling in the nucleus accumbens promotes arousal from isoflurane anaesthesia and restores communication between the nucleus accumbens and frontal cortex.
Preclinical multi-modal experiments show orexinergic inputs to the nucleus accumbens produce wake-active signals during isoflurane anesthesia; optogenetic and pharmacologic activation shortened emergence, reduced burst suppression, and restored NAc–frontal cortical communication, implicating OX1R on D1R-positive neurons.
Impact: Defines a conserved striatal circuit and receptor mechanism by which arousal can be pharmacologically modulated during general anesthesia, opening translational avenues to shorten emergence or alter EEG suppression patterns.
Clinical Implications: Provides a mechanistic rationale to explore orexinergic modulators or OX1R-targeted agents for perioperative modulation of emergence, agitation, or EEG suppression—pending safety and human trials.
Key Findings
- Orexinergic afferents in NAc are wake-active during isoflurane anesthesia and arousal.
- Optogenetic activation of NAc orexin terminals reduced burst suppression ratio markedly and shortened emergence.
- Microinjection of orexin-A into NAc promoted arousal; effects mediated via OX1R on D1R-positive neurons and restored NAc–frontal cortex communication.
2. Stellate ganglion block for preserving arteriovenous fistula in hemodialysis patients undergoing major lower limb orthopedic surgeries: randomized control trial.
A double-blind, sham-controlled RCT in 50 hemodialysis patients found preemptive ultrasound-guided stellate ganglion block before spinal anesthesia significantly increased AV fistula flow on postoperative days 1 and 7, improved Doppler velocities and resistive index, and reduced thrombosis (8% vs 36%) and functional failure (32% vs 64%).
Impact: Provides randomized, sham-controlled evidence that a widely available regional block can reduce a clinically important perioperative complication (AVF thrombosis) in a vulnerable dialysis population.
Clinical Implications: Consider ultrasound-guided stellate ganglion block before neuraxial anesthesia in hemodialysis patients undergoing major limb surgery to protect AVF patency, paired with Doppler surveillance and standard thrombosis prevention protocols.
Key Findings
- SGB increased AVF flow on POD1 and POD7 with large effect sizes (P<0.001).
- Improved PSV/EDV and lower RI in SGB group versus sham.
- Thrombosis 8% vs 36% and functional failure 32% vs 64% favoring SGB.
3. Comparison of pericapsular nerve group block and anterior quadratus lumborum block for hip fracture surgery: a randomized clinical trial.
In a double-blind RCT of 80 total hip arthroplasty patients, combined PENG + LFCN block reduced 24-hour IV morphine consumption and resting pain versus anterior QLB, while preserving quadriceps strength (no weakness in PENG+LFCN vs 15% weakness with anterior QLB at 6 hours).
Impact: Randomized evidence favoring a motor-sparing regional analgesic approach that reduces opioid consumption and preserves early mobilization after hip arthroplasty.
Clinical Implications: Adopt PENG + LFCN block as a motor-sparing analgesic option after THA to reduce 24-hour opioid needs and minimize quadriceps weakness, while monitoring longer-term functional outcomes in wider practice.
Key Findings
- PENG + LFCN reduced 24-hour IV morphine use compared with anterior QLB (p = 0.027).
- Resting VAS at 24 hours was significantly lower with PENG + LFCN (p < 0.001).
- Quadriceps weakness at 6 hours: 15% with anterior QLB vs 0% with PENG + LFCN.