Daily Anesthesiology Research Analysis
Three impactful anesthesiology-related studies stood out: a multicentre pediatric ICU trial showing inhaled isoflurane is non-inferior to intravenous midazolam for sedation, a large externally validated nomogram predicting intraoperative transfusion in major abdominal surgery, and an RCT showing no difference between pre- vs postoperative adductor canal block timing for total knee arthroplasty. Together, they inform pediatric ventilation sedation strategy, perioperative blood management, and pra
Summary
Three impactful anesthesiology-related studies stood out: a multicentre pediatric ICU trial showing inhaled isoflurane is non-inferior to intravenous midazolam for sedation, a large externally validated nomogram predicting intraoperative transfusion in major abdominal surgery, and an RCT showing no difference between pre- vs postoperative adductor canal block timing for total knee arthroplasty. Together, they inform pediatric ventilation sedation strategy, perioperative blood management, and pragmatic regional anesthesia workflow.
Research Themes
- Pediatric ICU inhaled sedation vs IV sedation
- Perioperative transfusion risk prediction and blood management
- Regional anesthesia workflow optimization (ACB timing)
Selected Articles
1. Inhaled isoflurane for sedation of mechanically ventilated children in intensive care (IsoCOMFORT): a multicentre, randomised, active-control, assessor-masked, non-inferiority phase 3 trial.
In this multicentre, assessor-masked non-inferiority RCT in ventilated children, inhaled isoflurane achieved a non-inferior proportion of time within target sedation (COMFORT-B) compared with intravenous midazolam. Serious adverse events were similar across groups and not attributed to study drugs, with no treatment-related deaths.
Impact: This is the first multicentre phase 3 RCT to establish non-inferiority of inhaled sedation versus IV midazolam in pediatric ICU ventilation, potentially broadening sedative options and workflows in PICU.
Clinical Implications: Isoflurane can be considered as an alternative to midazolam for maintaining target sedation in ventilated children, enabling centers with vaporizer capability to adopt inhaled sedation without compromising efficacy or safety.
Key Findings
- Non-inferiority met: least-squares mean difference in target COMFORT-B time 6.57 percentage points (95% CI -8.99 to 22.13) favoring isoflurane within the non-inferiority margin.
- Target sedation time: 68.94% (isoflurane) vs 62.37% (midazolam).
- Serious adverse events occurred in 31% (isoflurane) vs 24% (midazolam), none judged related; one severe hypotension per group; no treatment-related deaths.
Methodological Strengths
- Multicentre, randomized, active-controlled, assessor-masked design with pre-specified non-inferiority margin.
- Standardized sedation assessment every 2 hours using COMFORT-B with intention-to-treat analysis.
Limitations
- Sedation period limited to up to 48±6 hours; long-term outcomes were not assessed.
- Sample size modest (n=96), with 2:1 randomization leading to smaller control group.
Future Directions: Evaluate longer sedation courses, compare with other IV sedatives (e.g., propofol, dexmedetomidine), and assess outcomes including ventilation duration, delirium, and neurodevelopment.
2. Development and validation of a predictive model for transfusion in major abdominal surgery: a multicentre retrospective study.
Using 128,749 development cases with two large external validations (71,590 and 3,701), a seven-variable preoperative nomogram accurately predicted intraoperative RBC transfusion in major abdominal surgery (C-statistics ~0.85 with good calibration). Predictors included age, ASA status, ESC surgical risk, hemoglobin, platelets, INR, and albumin.
Impact: Provides a scalable, externally validated tool for preoperative blood planning, potentially reducing unnecessary crossmatches and enabling targeted patient blood management.
Clinical Implications: Hospitals can implement the nomogram to triage blood product preparation and optimize patient blood management pathways before major abdominal surgery.
Key Findings
- Development cohort n=128,749; external validations n=71,590 and n=3,701 across tertiary hospitals and an open dataset.
- Seven preoperative variables (age, ASA, ESC surgical risk, hemoglobin, platelets, INR, albumin) yielded strong discrimination: C-statistics 0.857, 0.847, 0.848.
- Good calibration across predicted risk spectrum; intraoperative RBC transfusion rates were 6.0%, 4.5%, and 7.3% in development and validation sets.
Methodological Strengths
- Extremely large sample size with two external validations enhancing generalizability.
- Transparent variable selection via LASSO with discrimination and calibration assessment.
Limitations
- Retrospective design with potential residual confounding and institutional practice variability.
- Model limited to major abdominal surgeries; performance in other surgical domains remains to be tested.
Future Directions: Prospective impact studies to assess clinical and economic benefits, integration into EHR for real-time decision support, and adaptation to other surgical specialties.
3. Preoperative Versus Postoperative Adductor Canal Block for Total Knee Arthroplasty: A Randomized Controlled Trial.
In a blinded RCT of TKA patients comparing pre- versus immediate postoperative adductor canal block (20 mL 0.2% ropivacaine), there were no differences in pain scores, opioid consumption, nausea/vomiting, or length of stay at 2 and 24 hours. Timing can be chosen based on logistical considerations.
Impact: Provides randomized evidence that ACB timing does not affect early outcomes, enabling workflow flexibility without compromising analgesia.
Clinical Implications: Clinicians can place ACB either pre- or postoperatively in TKA without affecting early pain or opioid use, potentially improving operating room throughput and scheduling.
Key Findings
- Randomized comparison of preoperative (n=47) vs postoperative (n=37) ACB using 20 mL 0.2% ropivacaine with blinded clinical staff.
- No between-group differences in pain (VAS), opioid consumption (MME), nausea/vomiting at 2 and 24 hours postoperatively.
- Length of stay metrics (hours, nights, same-day/next-day discharge) were similar between groups.
Methodological Strengths
- Randomized design with blinded clinical staff and predefined outcomes.
- Standardized block technique and consistent perioperative protocols.
Limitations
- Single-institution with two surgeons and modest sample size limits generalizability and power to detect small differences.
- Outcomes limited to early postoperative period (up to 24 hours); functional recovery not assessed.
Future Directions: Larger multicentre trials assessing longer-term pain, function, and rehabilitation milestones; exploration of interactions with adjuncts (e.g., dexamethasone) and continuous catheters.