Daily Anesthesiology Research Analysis
A network meta-analysis of 51 randomized trials shows that intra-operative low tidal volume ventilation with appropriate PEEP reduces postoperative pulmonary complications versus high tidal volume/zero PEEP. An analysis of 1.85 million cardiac surgeries found no association between deeper hypothermia during cardiopulmonary bypass and postoperative stroke. A multicountry point-prevalence study revealed that 1 in 8 hospitalized adults are critically ill, with 96% managed outside ICUs and an 18.7%
Summary
A network meta-analysis of 51 randomized trials shows that intra-operative low tidal volume ventilation with appropriate PEEP reduces postoperative pulmonary complications versus high tidal volume/zero PEEP. An analysis of 1.85 million cardiac surgeries found no association between deeper hypothermia during cardiopulmonary bypass and postoperative stroke. A multicountry point-prevalence study revealed that 1 in 8 hospitalized adults are critically ill, with 96% managed outside ICUs and an 18.7% hospital mortality.
Research Themes
- Lung-protective intra-operative ventilation to prevent postoperative pulmonary complications
- Temperature management during cardiopulmonary bypass and neurologic outcomes
- Global burden and location of critical illness across hospital wards
Selected Articles
1. Intra-operative ventilation strategies and their impact on clinical outcomes: a systematic review and network meta-analysis of randomised trials.
Across 51 randomized trials, low tidal volume strategies consistently reduced postoperative pulmonary complications versus high tidal volume with zero PEEP. Low tidal volume with personalized or higher PEEP (with or without recruitment manoeuvres) provided additional benefit over high tidal volume/zero PEEP, and personalized PEEP modestly improved outcomes versus low PEEP under low tidal volume. Evidence certainty was generally moderate.
Impact: This synthesis clarifies optimal intra-operative ventilation components across diverse surgeries, supporting broad implementation of lung-protective ventilation with appropriate PEEP to reduce postoperative pulmonary complications.
Clinical Implications: Adopt low tidal volumes with non-zero PEEP as default intra-operative ventilation for non-cardiothoracic surgery. Where feasible, personalize PEEP and consider recruitment manoeuvres, while monitoring hemodynamics and driving pressures.
Key Findings
- Compared with high tidal volume/zero PEEP, low tidal volume strategies reduced postoperative pulmonary complications (RRs 0.44–0.65 across PEEP/recruitment combinations; moderate certainty).
- Low tidal volume with personalized PEEP likely reduced complications versus low tidal volume/low PEEP (RR 0.85, 95% CI 0.73–0.99).
- Benefits were observed across several acceptable PEEP levels, supporting flexibility in PEEP selection within lung-protective ventilation.
Methodological Strengths
- Network meta-analysis spanning 51 randomized controlled trials with direct and indirect comparisons.
- Consistent outcome definitions for postoperative pulmonary complications and moderate-certainty estimates.
Limitations
- Heterogeneity in PEEP titration methods and recruitment manoeuvre protocols across trials.
- Total sample size across studies not reported in abstract; applicability limited to non-cardiothoracic surgery.
Future Directions: Define standardized, clinically feasible PEEP personalization strategies and evaluate integration with driving pressure targets and hemodynamic outcomes.
2. Hospital burden of critical illness across global settings: a point prevalence and cohort study in Malawi, Sri Lanka and Sweden.
Among 3,652 adult inpatients across eight hospitals in Malawi, Sri Lanka, and Sweden, the point prevalence of critical illness was 12.0% with 18.7% hospital mortality. Critically ill patients had a 7.5-fold higher crude odds of death versus non-critically ill, and 96.1% were cared for in general wards outside ICUs.
Impact: This study quantifies a substantial, often hidden burden of critical illness outside ICUs across diverse health systems, highlighting a major target for scalable, low-cost critical care interventions.
Clinical Implications: Hospitals should implement essential, low-cost critical care in general wards (e.g., early identification using vital signs, oxygen therapy, fluid resuscitation, monitoring) and strengthen escalation pathways to ICU.
Key Findings
- Point prevalence of critical illness among adult inpatients was 12.0% (95% CI 11.0–13.1).
- Hospital mortality among critically ill patients was 18.7% (95% CI 15.3–22.6); crude OR of death vs non-critically ill was 7.5 (95% CI 5.4–10.2).
- 96.1% (95% CI 93.9–97.6) of critically ill patients were treated in general wards rather than ICUs.
Methodological Strengths
- Prospective, hospital-wide point-prevalence with 30-day outcome follow-up across multiple countries and income settings.
- Standardized definition using severely deranged vital signs to identify critical illness.
Limitations
- Single-day point-prevalence snapshots per site may miss temporal variation in caseload.
- Vital sign-based definition may misclassify some patients; generalizability limited to eight hospitals.
Future Directions: Test ward-based, essential critical care bundles and early warning systems at scale and evaluate effects on mortality and ICU utilization across health systems.
3. Lowest Measured Temperature and Adverse Outcomes after Cardiac Surgery: Analysis of the Society of Thoracic Surgeons Adult Cardiac Surgery DatabaseTM.
In 1,847,808 CPB cases, there was no adjusted association between the lowest measured intraoperative temperature and postoperative stroke. LMT was also not associated with encephalopathy/coma or 30-day mortality. Lower LMTs were linked to less acute kidney injury and pneumonia, whereas higher LMTs were associated with more reoperation for bleeding.
Impact: This definitive, practice-informing analysis challenges routine use of deeper hypothermia to prevent neurologic injury in CPB and supports individualized temperature strategies.
Clinical Implications: Avoid routine deeper hypothermia solely to reduce stroke risk during CPB. Balance temperature targets against risks (e.g., bleeding) and potential organ-specific effects, tailoring to patient/procedure.
Key Findings
- No association between lowest measured intraoperative temperature and postoperative stroke after adjustment (P=0.316).
- LMT was not associated with encephalopathy/coma (P=0.649) or 30-day mortality (P=0.691).
- Acute kidney injury and pneumonia were less common at lower LMTs, while higher LMTs were linked to increased reoperation for bleeding.
Methodological Strengths
- Very large multicenter cohort (1,847,808 patients) with propensity score-weighted regression and nonlinear modeling.
- Comprehensive evaluation of neurologic and non-neurologic adverse outcomes.
Limitations
- Observational design susceptible to residual confounding and measurement bias in temperature acquisition.
- Database limitations (e.g., lack of cerebral temperature data, perfusion nuances) may mask subgroup effects.
Future Directions: Randomized trials or quasi-experimental studies to define optimal CPB temperature strategies by procedure risk, age, and perfusion technique, integrating bleeding and organ outcomes.