Daily Anesthesiology Research Analysis
Three studies stand out in anesthesiology and perioperative care. A network meta-analysis of 74 RCTs shows prophylactic continuous infusion of norepinephrine or phenylephrine best prevents spinal anesthesia-induced hypotension and intraoperative nausea/vomiting during cesarean delivery without harming neonatal outcomes. In ECPR, a ≥4% SpO2–SaO2 discrepancy at 24 hours independently predicts mortality, underscoring the need for arterial validation of oximetry. A meta-analysis supports erector spi
Summary
Three studies stand out in anesthesiology and perioperative care. A network meta-analysis of 74 RCTs shows prophylactic continuous infusion of norepinephrine or phenylephrine best prevents spinal anesthesia-induced hypotension and intraoperative nausea/vomiting during cesarean delivery without harming neonatal outcomes. In ECPR, a ≥4% SpO2–SaO2 discrepancy at 24 hours independently predicts mortality, underscoring the need for arterial validation of oximetry. A meta-analysis supports erector spinae plane block after cardiac surgery to reduce opioid use and late-phase pain, with modest effects on ventilation duration.
Research Themes
- Vasopressor strategy for spinal anesthesia-induced hypotension in cesarean delivery
- Accuracy and prognostic value of oxygenation monitoring in ECPR
- Regional anesthesia to optimize analgesia after cardiac surgery
Selected Articles
1. Norepinephrine vs. phenylephrine for spinal hypotension in cesarean section: a network meta-analysis.
Across 74 RCTs (n=7,798), prophylactic continuous infusion of norepinephrine or phenylephrine reduced spinal anesthesia-related hypotension and intraoperative nausea/vomiting compared with phenylephrine bolus, without compromising neonatal outcomes. Adverse event profiles differed (more bradycardia with phenylephrine; more hypertension with infusions), but efficacy was similar between norepinephrine and phenylephrine infusions.
Impact: This synthesis provides high-level evidence to standardize vasopressor strategy for cesarean spinal anesthesia, favoring prophylactic infusion over bolus dosing. It can immediately inform protocols, education, and quality improvement in obstetric anesthesia.
Clinical Implications: Adopt prophylactic continuous infusion of either norepinephrine or phenylephrine during cesarean spinal anesthesia to reduce hypotension and IONV; choose agent considering maternal heart rate (phenylephrine more bradycardia-prone) and institutional familiarity. Routine neonatal outcomes appear unaffected.
Key Findings
- Prophylactic infusion of norepinephrine or phenylephrine reduced IONV versus phenylephrine bolus (RR 0.47 and 0.54, respectively).
- Prophylactic infusion significantly decreased postspinal hypotension (NE RR 0.25; PE RR 0.29).
- Apgar scores and umbilical artery pH were similar across strategies.
- Adverse events differed by regimen: more bradycardia with phenylephrine, more hypertension with infusions; bolus strategies showed more tachycardia.
Methodological Strengths
- Large network meta-analysis including 74 RCTs with 7,798 participants
- Use of random-effects models and CINeMA for confidence assessment
Limitations
- Heterogeneity in dosing regimens, infusion targets, and prophylactic vs therapeutic use
- Adverse event reporting and definitions varied across trials
Future Directions: Head-to-head RCTs comparing fixed vs titrated infusion targets and norepinephrine vs phenylephrine in high-risk subgroups; standardized adverse event definitions and maternal satisfaction outcomes.
2. Pulse Oximetry and Arterial Blood Gas Oxygen Saturation Discrepancies and Mortality in Extracorporeal Cardiopulmonary Resuscitation Patients: An Extracorporeal Life Support Organization Registry Analysis.
In a multicenter ELSO registry analysis of 3,970 adults on ECPR, an SpO2–SaO2 discrepancy ≥4% at 24 hours was independently associated with higher in-hospital mortality (aOR 1.39). The signal was consistent across races/ethnicities and accompanied by higher lactate. Acute brain injury and extreme hyperoxemia/ hypoxemia were additional strong predictors.
Impact: Defines a pragmatic threshold for oximetry-arterial saturation discrepancy that correlates with mortality, prompting protocolized ABG validation and reassessment of monitoring strategies in ECPR.
Clinical Implications: In ECPR, do not rely solely on SpO2; obtain arterial co-oximetry when SpO2–SaO2 gap approaches or exceeds 4%, optimize probe placement/perfusion, and reassess oxygen targets to avoid unrecognized hypoxemia and harmful hyperoxemia.
Key Findings
- At 24 hours, SpO2–SaO2 ≥4% occurred in 16% and was linked to higher mortality (67% vs 59%; adjusted OR 1.39).
- Higher lactate, acute brain injury, hyperoxemia (PaO2 ≥200 mmHg) and hypoxemia (PaO2 <60 mmHg) independently predicted mortality.
- Association between saturation discrepancy and mortality did not differ by race/ethnicity.
Methodological Strengths
- Large multicenter registry with 3,970 ECPR patients from 496 centers
- Predefined threshold via spline analysis and multivariable adjustment for key confounders
Limitations
- Observational design with potential residual confounding and measurement variability across centers
- Single time-point (24h) assessment; device and perfusion factors could affect SpO2 accuracy
Future Directions: Prospective studies to test protocols using ABG-guided oxygenation targets when SpO2–SaO2 gap ≥4%; evaluate interventions to minimize discrepancy (probe site, perfusion optimization, signal quality).
3. Meta-analysis of erector spinae plane block efficacy in managing postoperative pain following cardiac surgery.
Across 23 RCTs after adult cardiac surgery, ESPB reduced opioid consumption and improved pain at 48–72 hours, with a modest reduction in ventilation time and no effect on ICU/hospital stay. Technique heterogeneity and moderate-to-low certainty highlight the need for standardized approaches and confirmatory trials.
Impact: Supports incorporating ESPB into multimodal analgesia pathways for cardiac surgery to reduce opioid exposure and late-phase pain, with signals toward enhanced recovery.
Clinical Implications: Consider ESPB as part of ERAS protocols for cardiac surgery to reduce opioid use and day 2–3 pain. Standardize block level, volume, timing, and consider continuous catheter vs single-shot based on resources and patient needs.
Key Findings
- No significant difference in 24-hour cough pain, but significant reductions at 48 h and 72 h (MD −0.60 and −0.67).
- 24-hour morphine consumption decreased (MD −2.04) and mechanical ventilation duration shortened by ~26.5 minutes.
- No differences in ICU or hospital length of stay; substantial heterogeneity and variable ESPB techniques.
Methodological Strengths
- Focus on randomized controlled trials in a single surgical domain
- Comprehensive assessment of pain, opioid consumption, and ventilation metrics
Limitations
- High heterogeneity (I² >50%) and moderate-to-low GRADE certainty
- Variability in ESPB techniques (level, volume, single-shot vs continuous) and co-analgesics
Future Directions: Standardized, adequately powered RCTs comparing continuous vs single-shot ESPB with uniform protocols; incorporate functional recovery, pulmonary complications, and patient-reported outcomes.