Daily ReportOct 19, 2026
Anesthesiology, October 19 edition
We read 35 papers and selected 3.
Summary
The most impactful findings were generated by a large, blinded cluster-randomized trial showing that supplemental operating-room air purification did not reduce surgical infections or mortality, thereby challenging a widely plausible infection-control strategy. A prospective biomarker study suggested that postoperative plasma tau increases may reflect redistribution from the central nervous system rather than acute neuronal injury. A randomized trial in older adults found that pre-induction continuous intra-arterial blood-pressure monitoring reduced the severity and duration of induction-related hypotension.
Research Themes
- Large-scale perioperative infection prevention trials
- Biomarkers and mechanisms of postoperative neurological change
- Hemodynamic monitoring and prevention of anesthesia-induced hypotension
Selected Articles
1. Operating Room Air Filtration-Sterilization and Surgical Infections: The ORACLE Randomized Trial in 110,538 Surgeries.
This large, fully blinded cluster-randomized trial evaluated supplemental operating-room air sterilization across 68 operating rooms and more than 110,000 surgeries. The intervention did not reduce the 30-day composite of surgical wound infection, infection-related complications, or death in inpatient surgery (8.1% versus 8.2%; odds ratio 0.98; P=0.609), and the trial stopped for futility.
Impact: The study provides unusually strong negative evidence against a costly and biologically plausible infection-control intervention. Its scale, blinding, cluster randomization, and futility stopping rule support redirecting infection-prevention resources toward strategies that limit direct wound contamination.
Clinical Implications: Routine supplemental operating-room air purification should not be assumed to reduce surgical infections or mortality. Infection-control programs should prioritize evidence-based measures that prevent direct wound contamination while avoiding resource-intensive air-treatment systems without demonstrated benefit.
Key Findings
- Among 58,938 randomized inpatients, the primary composite outcome occurred in 8.1% with active purification and 8.2% with sham purification.
- The effect estimate was close to null: odds ratio 0.98, 95% confidence interval 0.92 to 1.05, P=0.609.
- The trial crossed the prespecified futility boundary, and no benefit was detected in the combined inpatient and outpatient analysis either.
Methodological Strengths
- Very large multicenter cluster-randomized design with 68 operating rooms and more than 107,000 qualifying surgeries.
- Full blinding of investigators, clinicians, and patients using identical-looking sham devices, with intention-to-treat analysis and a prespecified futility boundary.
Limitations
- The study tested supplemental air purification within the participating operating-room environments and may not generalize to all ventilation systems or surgical settings.
- The funding organization approved the original protocol, although it was not involved in data acquisition, analysis, or manuscript preparation.
Future Directions: Future research should focus on direct wound-contamination pathways, targeted environmental interventions for high-risk procedures, and pragmatic comparisons of established infection-prevention bundles rather than routine supplemental air sterilization.
BACKGROUND: Surgical infections are the most common nosocomial infections and cause substantial morbidity and mortality. Operating rooms are relatively clean, but far from sterile. An unknown fraction of infections result from wound contamination by air-borne bacteria. We therefore tested the hypothesis that supplemental air purification reduces wound infections and related complications. METHODS: Operating rooms, our clusters, were each randomized in each 4-week blocks to either active or identical-looking sham supplemental air sterilization. All investigators, clinicians, and patients were fully blinded to treatment.
2. Brain-derived tau in plasma and cerebrospinal fluid after surgery: a prospective cohort substudy.
In this prospective cohort substudy, plasma and cerebrospinal-fluid brain-derived tau were measured serially after hip and knee arthroplasty. Plasma brain-derived tau increased rapidly by 254% at 4 hours, whereas cerebrospinal-fluid levels were initially unchanged and rose later; the pattern, together with inverse plasma–cerebrospinal-fluid associations, suggests redistribution rather than immediate neuronal injury.
Impact: The study addresses a clinically important concern that postoperative plasma tau necessarily indicates perioperative brain injury. By using a brain-derived tau assay in both plasma and cerebrospinal fluid, it offers a mechanistic reinterpretation that may prevent overdiagnosis of neuronal injury after surgery.
Clinical Implications: Postoperative plasma total tau should not be interpreted in isolation as proof of acute neuronal injury. Clinical studies and biomarker-based perioperative neurological assessment should consider compartmental redistribution, cerebrospinal-fluid dynamics, and brain-derived assays.
Key Findings
- Plasma brain-derived tau peaked at 4 hours after surgery with a 254% median increase and remained 31% above baseline at 48 hours.
- Cerebrospinal-fluid brain-derived tau was unchanged at 4 hours but increased by 51% at 48 hours.
- Higher postoperative plasma brain-derived tau was associated with higher cerebrospinal-fluid albumin and worse cognitive performance at 3 months, while plasma and cerebrospinal-fluid brain-derived tau were inversely associated.
Methodological Strengths
- Prospective serial sampling of both plasma and cerebrospinal fluid at multiple postoperative time points.
- Use of a brain-derived tau biomarker alongside total tau and 3-month cognitive assessment, enabling mechanistic interpretation beyond a single surrogate marker.
Limitations
- The study was a substudy of patients undergoing hip and knee arthroplasty, which may limit generalizability to other surgeries and patient populations.
- The observational biomarker design can demonstrate associations and temporal patterns but cannot establish that tau redistribution causes or prevents postoperative cognitive change.
Future Directions: Future studies should validate brain-derived tau across diverse surgical populations, integrate it with neuroimaging and blood–brain barrier measures, and determine whether perioperative interventions modify biomarker trajectories or long-term cognition.
BACKGROUND: Postoperative increases in plasma total tau (t-tau) protein have raised concerns that surgery can cause CNS injury. Brain-derived tau (BD-tau) is a novel biomarker that quantifies CNS-derived tau. We assessed BD-tau concentrations in plasma and CSF after surgery to investigate neuronal injury and mechanisms driving increases in plasma t-tau. METHODS: This was a substudy of a previous prospective cohort study enrolling adult patients undergoing hip and knee arthroplasty. We measured plasma and CSF BD-tau and t-tau before neuraxial anaesthesia (baseline) and at 4, 8, 24, 32, and 48 h after surgery and assessed cognitive performance at baseline and 3 months.
3. Continuous intra-arterial versus noninvasive blood pressure monitoring for preventing hypotension during anesthesia induction in patients aged ≥ 75 years undergoing noncardiac surgery: a randomized controlled trial.
This single-center randomized trial included 82 patients aged 75 years or older undergoing elective noncardiac surgery. Continuous intra-arterial monitoring initiated before induction reduced the area under the curve for mean arterial pressure below 65 mmHg, shortened hypotension duration, and enabled earlier vasoactive treatment compared with noninvasive monitoring.
Impact: The study tests a practical monitoring strategy in a high-risk population during a short but clinically vulnerable period. It provides preliminary randomized evidence that earlier and continuous blood-pressure information can improve prevention of induction-related hypotension in older adults.
Clinical Implications: For selected patients aged 75 years or older at high risk of hemodynamic instability, placing an arterial catheter before induction may facilitate earlier detection and treatment of hypotension. Routine use for all older patients cannot yet be recommended because the study was small and single-center.
Key Findings
- The median area under the curve for mean arterial pressure below 65 mmHg was 0 (0–6.09) mmHg·min with continuous intra-arterial monitoring versus 3.67 (0–26.45) mmHg·min with noninvasive monitoring (P=0.008).
- The duration of mean arterial pressure below 65 mmHg was shorter with intra-arterial monitoring: 0 (0–1.42) versus 0.87 (0–3.88) minutes (P=0.010).
- Vasoactive drugs were administered earlier with intra-arterial monitoring, and propofol and remifentanil doses were lower.
Methodological Strengths
- Randomized comparison with a prespecified, clinically meaningful blood-pressure exposure outcome using area under the curve.
- The primary outcome was assessed using invasive blood pressure in both groups, reducing measurement bias in outcome ascertainment.
Limitations
- The trial was single-center and included only 82 patients, limiting precision and external validity.
- It evaluated short-term hemodynamic outcomes and was not powered to determine effects on postoperative complications, organ injury, or mortality.
Future Directions: Multicenter trials should identify which older or hemodynamically vulnerable patients benefit most, compare arterial monitoring with advanced noninvasive continuous technologies, and evaluate whether reduced induction hypotension improves organ-specific and patient-centered outcomes.
BACKGROUND: Hypotension is common during the period after induction of general anesthesia and before surgical incision, particularly in older patients. The objective of this study was to compare the effectiveness of continuous intra-arterial pressure monitoring with that of noninvasive blood pressure monitoring in preventing hypotension during anesthesia induction in older patients (≥ 75 years) undergoing noncardiac surgery. METHODS: In this single-center, randomized controlled trial, 82 older patients who were scheduled for elective noncardiac surgery under general anesthesia were randomly assigned to the continuous intra-arterial pressure monitoring group or the noninvasive blood pressure monitoring group. The primary outcome was the area under the curve for mean arterial pressure (MAP) < 65 mmHg during the first 15 min after induction, based on invasive blood pressure measurements.