Daily Anesthesiology Research Analysis
Analyzed 42 papers and selected 3 impactful papers.
Summary
Three perioperative studies stand out today: a registered network meta-analysis identifies multimodal warming—especially a heated, humidified breathing circuit with integrated fluid warming—as most effective for intraoperative normothermia; a prospective cohort links higher preoperative plasma neurofilament light to postoperative delirium after cardiac surgery; and a single-center RCT shows high-flow nasal cannula reduces hypercapnia during ERCP sedation without lowering hypoxemia events.
Research Themes
- Perioperative temperature management and multimodal warming
- Neurocognitive risk stratification using blood biomarkers
- Respiratory support optimization during procedural sedation
Selected Articles
1. Airway warming devices in the context of single and multimodal strategies for intraoperative hypothermia: a network meta-analysis.
Across 25 RCTs (n=1404), a heated, humidified breathing circuit with integrated fluid warmer (MAK) and multimodal combinations (e.g., HH+IV+WM) produced higher end-of-surgery core temperatures than controls. Multimodal strategies consistently ranked above single modalities, with frequentist and Bayesian SUCRA rankings aligned.
Impact: Provides comparative effectiveness evidence to guide intraoperative warming, supporting multimodal strategies and identifying MAK as a top performer.
Clinical Implications: Adopt multimodal warming (e.g., airway heated humidification plus fluid and surface warming) for major surgeries; consider MAK where available, while acknowledging limited certainty and device availability.
Key Findings
- Included 25 RCTs with 1404 patients comparing airway and multimodal warming strategies.
- MAK and HH+IV+WM achieved significantly higher end-of-surgery core temperatures versus controls.
- Multimodal warming ranked superior to single-device methods across time points by SUCRA.
- Frequentist and Bayesian rankings were concordant, supporting robustness; overall certainty remains limited.
Methodological Strengths
- Registered network meta-analysis with both frequentist and Bayesian models and SUCRA ranking.
- Restriction to randomized controlled trials enhances internal validity.
Limitations
- Heterogeneity of devices and multimodal protocols and limited certainty of evidence.
- Potential small-study effects and variable risk-of-bias across included RCTs.
Future Directions: Large, head-to-head multicenter RCTs comparing standardized multimodal bundles versus best single-device strategies with patient-centered outcomes (shivering, surgical site infection) and cost-effectiveness.
BACKGROUND: This network meta-analysis (NMA) assessed the relative efficacy of airway warming devices and combined warming strategies for preventing intraoperative hypothermia. METHODS: We searched MEDLINE, EMBASE, CENTRAL, and Google Scholar to identify randomized controlled trials (RCTs) published through November 2025 that compared two or more warming strategies, including airway warming devices, in patients under general anesthesia. The primary outcome was intraoperative core temperature at the end of surgery. To establish the rank order of the evaluated warming strategies, frequentist and Bayesian NMAs were conducted and surface under the cumulative ranking curve (SUCRA) values were used. RESULTS: The systematic review and NMA included 25 RCTs involving 1404 patients. At the end of surgery, heated humidifiers (HHs), HH + intravenous fluid warmer (IV), HH + IV + water mattress (WM), and the Mega Acer Kit® (MAK)-a heated-humidified breathing circuit with an integrated fluid warming unit-were associated with significantly higher core temperatures than the control group. Based on the SUCRA values, MAK ranked highest at the end of surgery, followed by HH + IV + WM. Multimodal interventions generally ranked higher than single warming methods across all assessed time points, suggesting the superiority of multimodal warming approaches. The SUCRA values from the frequentist and Bayesian models were closely aligned, indicating the robustness of the analysis. CONCLUSION: Based on the available evidence, MAK may be the most effective among warming strategies involving airway warming devices. Overall, multimodal warming approaches may offer advantages over single-device strategies for perioperative temperature management, although the certainty of the evidence is limited. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42024534439.
2. Association Between Plasma Neurofilament Light Concentration and Postoperative Delirium After Cardiac Surgery.
In 151 older adults undergoing CPB cardiac surgery, postoperative delirium occurred in 40%. Higher preoperative and 6-hour postoperative plasma NFL were associated with POD, but perioperative changes were not; baseline NFL remained an independent predictor after adjustment.
Impact: Identifies a readily measurable blood biomarker that independently predicts postoperative delirium, enabling preoperative risk stratification.
Clinical Implications: Baseline plasma NFL could be incorporated into preoperative assessment to identify high-risk patients for targeted delirium prevention (e.g., depth-of-anesthesia management, transfusion minimization, nonpharmacologic bundles).
Key Findings
- Postoperative delirium occurred in 60/151 (40%) older cardiac surgery patients.
- Higher baseline and 6-hour postoperative log(NFL) were associated with POD; perioperative NFL changes were not.
- Baseline log(NFL) remained an independent predictor after multivariable adjustment.
- POD was also associated with CHF, lower education, transfusion, complex procedures, deeper anesthesia, and intraoperative burst suppression.
Methodological Strengths
- Prospective design with standardized twice-daily delirium assessments over 7 days.
- Multivariable modeling adjusting for key pre/intraoperative factors.
Limitations
- Single-center study limiting generalizability.
- Biomarker sampling limited to induction and 6 hours post-op; no longer-term kinetics.
Future Directions: Validate NFL thresholds in multicenter cohorts, integrate with EEG-derived anesthesia depth metrics, and test biomarker-guided delirium prevention pathways in RCTs.
OBJECTIVES: Patients undergoing cardiac surgery are at a high risk of developing postoperative delirium (POD), which is associated with increased morbidity and mortality. Neurofilament light chain (NFL), a neuronal cytoplasmic protein, is a marker of axonal injury. We investigated the association between perioperative plasma NFL concentration and POD. DESIGN: A prospective observational study. SETTING: A single institution of a tertiary university hospital PARTICIPANTS: A total of 151 patients aged ≥65 years scheduled for elective cardiac surgery with cardiopulmonary bypass. INTERVENTION: Plasma NFL levels were measured at induction and 6 hours postoperatively. POD was assessed twice daily for 7 days using the Confusion Assessment Method for the ICU or 3-Minute Diagnostic Interview for CAM-defined Delirium depending on intubation. The NFL values were log-transformed. Logistic regression was used to evaluate their associations with POD. Multivariable models were adjusted for preoperative and intraoperative variables. MEASUREMENTS AND MAIN RESULTS: Delirium occurred in 60 (40%) patients. Compared with those without POD, affected patients had higher rates of congestive heart failure, a lower educational status, and a higher incidence of erythrocyte transfusion. Delirium was also associated with complex procedures, prolonged deep anesthesia, and intraoperative burst suppression. Both baseline and postoperative log(NFL) were significantly associated with delirium, whereas perioperative changes in NFL were not. In the multivariable analysis, baseline log(NFL) remained an independent predictor of POD. CONCLUSIONS: Preoperative plasma NFL concentration was associated with POD, whereas changes in NFL were not. Baseline NFL may serve as a clinically useful biomarker for risk stratification in older patients undergoing cardiac surgery.
3. High-flow nasal cannula improves pulmonary gas exchange during endoscopic retrograde cholangiopancreatography: A single-center randomized controlled trial.
Among 191 ERCP patients stratified by OSA and randomized to HFNC or standard nasal cannula, HFNC reduced transcutaneous CO2 and the desaturation time burden (AUC for SpO2<90%) but did not lower the incidence of hypoxemia events.
Impact: Provides randomized evidence informing oxygenation strategies during ERCP sedation, clarifying HFNC’s benefits (hypercapnia reduction) and limits (no reduction in hypoxemia events).
Clinical Implications: Consider HFNC for high-risk ERCP patients to mitigate hypercapnia and reduce desaturation burden, while maintaining vigilance for hypoxemic events and airway rescue needs.
Key Findings
- Randomized 191 ERCP patients (92 HFNC vs 99 NC) with OSA stratification.
- HFNC did not significantly reduce hypoxemia events (3 vs 13; p=0.05).
- HFNC reduced hypercapnia (PtCO2 51 vs 56 mmHg; p<0.005).
- HFNC reduced desaturation burden (AUC SpO2<90%: 175 vs 268 %·min; p<0.001).
Methodological Strengths
- Randomized, stratified design with clinically relevant gas exchange endpoints.
- Adequate sample size for single-center RCT and objective physiologic measurements (PtCO2, SpO2 AUC).
Limitations
- Single-center design; borderline p-value for hypoxemia event difference.
- Rescue maneuvers and sedation protocols may influence outcomes and generalizability.
Future Directions: Multicenter RCTs powered for clinical outcomes (airway interventions, unplanned ventilation) and subgroup analyses (OSA, BMI, ASA class) to refine HFNC indications.
BACKGROUND: Sedation during endoscopic retrograde cholangiopancreatography procedures (ERCP) increases the risk of hypoxemia and the need for respiratory support in high-risk patients. High flow nasal cannula (HFNC) provides humidified gas at high flow rates, improving alveolar ventilation. We aim to assess whether ventilatory support with HFNC improves gas exchange compared to standard low-flow nasal cannula (NC). METHODS: Single-center, randomized controlled trial, in adults undergoing ERCP. After providing informed consent, participants were randomized in a 1:1 ratio following obstructive sleep apnea (OSA) stratification to receive ventilatory support with HFNC (60 L·min RESULTS: 191 patients were included (38% female, median age 67 years, 59% ASA III-IV, and 38% with OSA). A total of 92 patients were randomized to HFNC and 99 to NC. Sixteen (8%) patients presented hypoxemic events (SpO₂ < 90%) and 64 (33%) needed airway rescue maneuvers. HFNC did not significantly reduce the incidence of hypoxemic events (3 vs. 13; p = 0.05). However, HFNC significantly reduced hypercapnia with lower PtCO₂ (HFNC, 51 [44-59] vs. NC, 56 [45-75] mmHg; p < 0.005), and the AUC for SpO₂ < 90% (HFNC, 175[167-226] vs. NC, 268[241-342] %·min; p < 0.001). CONCLUSIONS: HFNC did not reduce the incidence of hypoxemic events. However, it resulted in a reduction of hypercapnic events.