Weekly Anesthesiology Research Analysis
This week’s anesthesiology literature is dominated by large randomized trials and mechanistic perioperative studies that directly inform practice: (1) a 2,200-patient international RCT (PROTHOR) indicates routine high PEEP with recruitment during one‑lung ventilation offers no PPC benefit and increases intraoperative hypotension/arrhythmias; (2) a personalized prehabilitation randomized trial demonstrated improved functional readiness, reduced moderate-to-severe postoperative complications, and
Summary
This week’s anesthesiology literature is dominated by large randomized trials and mechanistic perioperative studies that directly inform practice: (1) a 2,200-patient international RCT (PROTHOR) indicates routine high PEEP with recruitment during one‑lung ventilation offers no PPC benefit and increases intraoperative hypotension/arrhythmias; (2) a personalized prehabilitation randomized trial demonstrated improved functional readiness, reduced moderate-to-severe postoperative complications, and measurable immune modulation; (3) mechanistic EEG evidence from a randomized study links prolonged intraoperative Valsalva (>5.2 min) to burst suppression and worse immediate recovery, providing an actionable intraoperative time threshold. Across the week, emphasis fell on patient-centered ERAS strategies, nuanced regional anesthesia choices, and validated prognostic indices to guide perioperative resource allocation.
Selected Articles
1. Effects of intraoperative higher versus lower positive end-expiratory pressure during one-lung ventilation for thoracic surgery on postoperative pulmonary complications (PROTHOR): a multicentre, international, randomised, controlled, phase 3 trial.
In a 2,200-patient, 28-country phase 3 RCT, intraoperative high PEEP with recruitment during one‑lung ventilation did not reduce postoperative pulmonary complications compared with lower PEEP without recruitment. High PEEP increased intraoperative hypotension and new arrhythmias, while low PEEP required more hypoxemia rescue maneuvers. No differences were observed in extrapulmonary postoperative complications.
Impact: A definitive, large international RCT that challenges a widely used intraoperative lung‑expansion strategy and provides immediate guidance to reduce potentially harmful routine high‑PEEP application during one‑lung ventilation.
Clinical Implications: Avoid routine use of high PEEP with recruitment during one‑lung ventilation in patients similar to trial population (BMI <35 kg/m2). Prefer lower PEEP/permissive atelectasis with individualized rescue maneuvers and monitor for hemodynamic instability when higher PEEP is considered.
Key Findings
- Primary outcome (postoperative pulmonary complications) similar: 53.6% (high PEEP) vs 56.4% (low PEEP); absolute risk difference −2.68 percentage points (95% CI −6.36 to 1.01); p=0.155.
- High PEEP increased intraoperative complications: hypotension (37.3% vs 14.3%) and new arrhythmias (9.9% vs 3.9%).
- Low PEEP had more hypoxemia rescue maneuvers (8.8% vs 3.3%); no differences in extrapulmonary postop complications or total adverse events.
2. Immune Modulation by Personalized vs Standard Prehabilitation Before Major Surgery: A Randomized Clinical Trial.
A single‑blinded randomized trial (n=58, 54 completed) found personalized, coached prehabilitation improved preoperative physical performance (6MWT), reduced moderate-to-severe postoperative complications, and uniquely altered high-dimensional immune signaling (mass cytometry) compared with a standard paper program. Immune changes corresponded to dampened proinflammatory signaling in myeloid and T‑cell subsets.
Impact: Connects an actionable, scalable perioperative intervention (personalized prehab) to measurable immune modulation and clinical benefit, bridging mechanistic biology with surgical outcomes and suggesting biomarkers for tailoring interventions.
Clinical Implications: Consider integrating personalized, coached prehabilitation into perioperative pathways for major surgery to improve readiness and reduce complications; explore immune-based monitoring to tailor intensity and timing.
Key Findings
- 6-minute walk distance improved in the personalized group (median increase from 496 to 546; P=0.03).
- Fewer moderate-to-severe postoperative complications with personalized prehab (4 vs 11; P=0.04).
- Mass cytometry revealed cell-type–specific dampening of inflammatory signaling (AUROC 0.88 for distinguishing immune changes in personalized group; P<0.001).
3. Impact of valsalva maneuver duration on brain function in patients undergoing high-intensity focused ultrasound liver ablation: a randomized controlled trial.
A three‑arm randomized trial (n=153) during HIFU under general anesthesia found Valsalva maneuvers >5.2 minutes per episode dramatically increased EEG burst suppression (66.7% vs 30.8% for ≤5.2 min and 2.0% control), reduced alpha/beta power, increased emergence agitation, and worsened recovery scores. The study proposes an actionable intraoperative limit (≤5.2 min) for Valsalva episodes to mitigate neurophysiologic stress.
Impact: Provides mechanistic EEG evidence linking a common procedural maneuver to cortical suppression and worse immediate recovery, producing an evidence-based intraoperative time threshold that can be implemented immediately.
Clinical Implications: Coordinate with procedural teams to limit continuous Valsalva episodes to ≤5.2 minutes when feasible, consider EEG-guided anesthetic titration to avoid burst suppression, and anticipate/aggressively manage emergence agitation after prolonged Valsalva.
Key Findings
- Burst suppression rates: control 2.0%, short VM (≤5.2 min) 30.8%, long VM (>5.2 min) 66.7% (p<0.001).
- Long VM decreased alpha/beta power and increased permutation entropy, indicating cortical depression.
- Emergence agitation highest in long VM group (64.7%) and QoR‑15 scores lowest; delirium differences not statistically significant.