Daily Anesthesiology Research Analysis
Three impactful studies reshape perioperative and critical care practice: a pre-planned Bayesian re-analysis of the PRECISe trial indicates high protein provision (2.0 g/kg/day) in ICU likely confers harm; multimodal nociception monitoring under total intravenous anesthesia shows pupillary reflex dilation best tracks remifentanil effect; and a meta-analysis supports lactate and pH as independent prognostic biomarkers after out-of-hospital cardiac arrest.
Summary
Three impactful studies reshape perioperative and critical care practice: a pre-planned Bayesian re-analysis of the PRECISe trial indicates high protein provision (2.0 g/kg/day) in ICU likely confers harm; multimodal nociception monitoring under total intravenous anesthesia shows pupillary reflex dilation best tracks remifentanil effect; and a meta-analysis supports lactate and pH as independent prognostic biomarkers after out-of-hospital cardiac arrest.
Research Themes
- Precision nutrition in critical care
- Multimodal nociception monitoring during anesthesia
- Prognostication after cardiac arrest
Selected Articles
1. The impact of high versus standard enteral protein provision on functional recovery following intensive care admission: A pre-planned Bayesian analysis of the PRECISe trial.
In a pre-specified Bayesian re-analysis of the PRECISe RCT (n=935), targeting 2.0 g/kg/day protein showed a 0% posterior probability of improving EQ-5D-5L and only an 8% chance of any mortality benefit, with a 47% posterior probability of clinically important harm (>5% absolute risk increase) for 60-day mortality. Findings were robust across multiple prior assumptions.
Impact: This analysis challenges protein up-titration in ICU nutrition by quantifying harm probability, offering actionable evidence beyond frequentist non-significance. It may shift nutrition targets toward standard dosing.
Clinical Implications: Avoid routine high-protein targets (2.0 g/kg/day) in the early ICU course; consider standard protein targets (~1.3 g/kg/day) while individualizing based on catabolic state and tolerance. Discuss potential harm with multidisciplinary nutrition teams.
Key Findings
- Posterior probability of benefit on EQ-5D-5L with high protein was 0%.
- For 60-day mortality, high protein had only an 8% chance of any benefit and a 47% probability of clinically important harm (>5% absolute risk increase).
- Results were robust across sensitivity analyses using different priors.
Methodological Strengths
- Pre-planned, pre-specified Bayesian framework with weakly informative and sensitivity priors
- Large RCT dataset (n=935) with clinically meaningful endpoints (EQ-5D-5L, 60-day mortality)
Limitations
- Secondary analysis; original trial not powered for all functional outcomes under a frequentist framework
- Potential sensitivity to prior assumptions despite comprehensive sensitivity analyses
Future Directions: Prospective, adaptive trials testing personalized protein targets by phenotype (e.g., sarcopenia, AKI) and timing, with Bayesian decision rules and patient-centered outcomes.
2. Cortical, subcortical, brainstem and autonomic responses to nociception under total intravenous anesthesia.
Under TIVA with standardized tetanic stimuli, multiple nociception indices changed, but pupillary reflex dilation (PRD) best tracked remifentanil effect-site concentration, whereas ANI, NOL, and qNOX did not. Low remifentanil levels enabled noxious-evoked EEG signatures (≈25 Hz power increase, alpha decrease), supporting multimodal monitoring to balance nociception and antinociception.
Impact: Provides comparative evidence across cortical, autonomic, and behavioral nociception measures linking PRD to opioid levels, informing intraoperative analgesic titration strategies.
Clinical Implications: Prioritize PRD (with HR and BIS context) to guide remifentanil titration; combine with EEG spectral signatures for inadequate analgesia detection when opioid levels are low. Consider multimodal integration rather than single-index reliance.
Key Findings
- PRD showed the strongest correlation with remifentanil concentrations; ANI, NOL, and qNOX did not correlate significantly.
- Noxious stimulation induced significant changes in ANI, BIS, HR, NOL, PRD, and qNOX.
- EEG revealed increased ≈25 Hz power and decreased alpha (8–12 Hz) after noxious stimuli, especially when PRD was low and opioid levels were low.
Methodological Strengths
- Standardized nociceptive stimulus with concurrent multimodal recordings
- Target-controlled infusion allowing controlled pharmacologic gradients
Limitations
- Sample size and single-center scope not specified; generalizability may be limited
- Physiologic correlations do not establish causal clinical benefit; no outcome endpoints
Future Directions: Prospective trials integrating PRD and EEG with pharmacokinetic–pharmacodynamic models to improve analgesic titration and patient-centered outcomes (pain recall, hemodynamic stability).
3. Lactate and pH as Independent Biomarkers for Prognosticating Meaningful Post-out-of-Hospital Cardiac Arrest Outcomes: A Systematic Review and Meta-Analysis.
This systematic review and meta-analysis synthesizes evidence that admission/early lactate levels and arterial pH independently predict meaningful outcomes following out-of-hospital cardiac arrest. The findings support integrating these routinely available biomarkers into multimodal prognostication pathways.
Impact: Consolidates heterogeneous literature to validate two widely available, low-cost biomarkers for OHCA prognostication, informing protocols and family counseling.
Clinical Implications: Use early lactate and pH in a multimodal prognostication algorithm post-OHCA, while avoiding self-fulfilling bias by deferring definitive decisions until guidelines’ recommended time points and corroborating with neurologic assessments and imaging.
Key Findings
- Early lactate levels independently associate with meaningful outcomes after OHCA.
- Arterial pH is an independent prognostic biomarker in post-OHCA patients.
- Supports incorporation of lactate and pH into standardized prognostication pathways.
Methodological Strengths
- Systematic synthesis across multiple studies with meta-analytic pooling
- Focus on routinely obtainable, objective laboratory biomarkers
Limitations
- Potential heterogeneity in timing of sampling, outcome definitions, and confounder adjustment
- Risk of publication bias and reliance on observational data in primary studies
Future Directions: Prospective multicenter validation with standardized sampling windows and predefined patient-centered outcomes; integration with machine learning prognostic models.