Daily Anesthesiology Research Analysis
Analyzed 28 papers and selected 3 impactful papers.
Summary
Today's most impactful studies addressed opioid-sparing regional anesthesia, interpretable machine-learning prediction of unplanned perioperative admissions, and the neurocognitive safety profile of remimazolam in older surgical patients. The strongest evidence came from a registered randomized non-inferiority trial and a meta-analysis of 15 randomized controlled trials, while the large machine-learning cohort demonstrated clinically relevant predictive performance but requires prospective validation.
Research Themes
- Opioid-sparing and respiratory-sparing regional anesthesia
- Interpretable machine learning for perioperative risk prediction
- Neurocognitive outcomes and hemodynamic safety of remimazolam
Selected Articles
1. Ultrasound-Guided Infraspinatus-Teres Minor Interfascial Block versus Interscalene Brachial Plexus Block for Analgesia After Arthroscopic Shoulder Surgery: A Randomized Non-Inferiority Clinical Trial
In 82 randomized patients, ITMB achieved non-inferior 24-hour postoperative oxycodone consumption compared with ISB. ITMB reduced the incidence of early hemidiaphragmatic paralysis, although ISB provided greater analgesia immediately after surgery and ITMB showed more sustained later analgesic effects.
Impact: This trial provides prospective comparative evidence for a potentially phrenic-sparing alternative to interscalene block, a standard technique associated with hemidiaphragmatic paralysis. The registered non-inferiority design and intention-to-treat analysis strengthen its relevance to opioid-sparing and respiratory-risk reduction strategies.
Clinical Implications: ITMB may be considered when adequate shoulder analgesia is needed but preservation of diaphragmatic function is important, particularly in patients with limited pulmonary reserve. Clinicians should recognize that analgesic timing differs from ISB and plan rescue analgesia accordingly.
Key Findings
- The mean 24-hour oxycodone consumption was 10.92 mg with ITMB and 11.26 mg with ISB; the between-group difference was 0.34 mg, with a 95% confidence interval of -1.42 to 2.11 mg, supporting non-inferiority.
- ITMB reduced the incidence of early hemidiaphragmatic paralysis compared with ISB.
- ISB provided stronger early postoperative analgesia, whereas ITMB had more sustained analgesic effects later in the postoperative period.
Methodological Strengths
- Randomized two-arm non-inferiority design with blinded participants and outcome assessors
- Prespecified primary outcome, registered protocol, and both per-protocol and intention-to-treat analyses
Limitations
- The sample size was small and the study was conducted in a single clinical setting, limiting generalizability.
- Two ITMB participants were excluded from the per-protocol analysis, and the study was not powered to assess uncommon complications or long-term functional outcomes.
Future Directions: Larger multicenter trials should confirm respiratory benefits, evaluate patients with pulmonary disease, compare different local anesthetic volumes, and assess recovery, patient satisfaction, and persistent postoperative pain.
BACKGROUND: This randomized non-inferiority trial was designed to verify whether ultrasound-guided infraspinatus-teres minor interfascial block (ITMB) could produce non-inferior postoperative analgesia in adult patients undergoing arthroscopic shoulder surgery compared with ultrasound-guided interscalene brachial plexus block (ISB), while also comparing the early respiratory safety profiles and postoperative adverse events of the two techniques. METHODS: This trial adopted a two-arm parallel-group design with blinding for participants and all outcome assessors. A total of 82 eligible patients were randomly assigned 1:1 to receive either ITMB (n=41) or ISB (n=41) with 25 mL 0.375% ropivacaine for each nerve block. Two participants in the ITMB group were excluded from the per-protocol (PP) analysis due to intraoperative conversion to open surgery and unplanned intensive care unit admission, leaving 39 ITMB patients and 41 ISB patients for primary PP analysis; intention-to-treat (ITT) analysis covering all 82 randomized patients was additionally conducted to validate robustness. The primary prespecified outcome was 24-hour postoperative total oxycodone consumption, with a predefined non-inferiority margin of -5 mg.
2. Predicting patient care pathway deviations and their consequences in anaesthesia using machine learning
Among 51,112 ambulatory anesthesia procedures, unplanned admission occurred in 9.08% of patients. The explainable boosting machine achieved the best discrimination and precision-recall performance, with an area under the receiver operating characteristic curve of 0.826 and average precision of 0.472, while maintaining interpretability; however, risk probabilities required recalibration.
Impact: The study demonstrates that interpretable machine learning can identify patients at risk of deviating from an intended day-case pathway using routinely collected preoperative data. Its emphasis on precision-recall performance and calibration addresses practical issues often overlooked in perioperative prediction studies.
Clinical Implications: A validated model could support preoperative triage, staffing, bed planning, and shared decision-making for ambulatory anesthesia. It should not yet be used autonomously because prospective external validation and recalibration are still required.
Key Findings
- Unplanned admission occurred in 9.08% of 51,112 ambulatory anesthesia procedures.
- The explainable boosting machine achieved the highest area under the receiver operating characteristic curve at 0.826, compared with 0.595 for logistic regression.
- The explainable boosting machine had the highest average precision at 0.472 and remained stable between validation and test datasets, although all models overestimated risk and required recalibration.
Methodological Strengths
- Very large consecutive clinical dataset with separate training, validation, and test sets
- Comparison of seven algorithms using discrimination, precision-recall, and calibration metrics, with class-imbalance correction applied only to the training data
Limitations
- The retrospective design and data from one Belgian network may limit causal interpretation and external generalizability.
- All models overestimated risk, and prospective external validation, recalibration, and assessment of clinical utility were not performed.
Future Directions: Future studies should perform multicenter prospective external validation, recalibrate predicted probabilities, evaluate fairness across patient subgroups, and test whether model-guided interventions reduce unplanned admissions without causing unnecessary cancellations.
Deviation from the intended perioperative care pathway, particularly unplanned admission after day-case surgery, affects patient safety and the efficient organisation of care. We aimed to develop and compare interpretable machine-learning models predicting such deviations from information available before surgery. In this retrospective study, 51,112 consecutive ambulatory anaesthesia procedures from a Belgian network were analysed, with unplanned admission as the outcome. Data were partitioned into training, validation, and test sets; class imbalance was addressed with SMOTENC on the training data alone. Seven algorithms: logistic regression, decision tree, random forest, XGBoost, LightGBM, histogram-based gradient boosting, and explainable boosting machine (EBM) were compared using discrimination, precision-recall, and calibration metrics at two operating points.
3. The impact of remimazolam on postoperative neurocognitive disorder in elderly surgical patients: a systematic review and meta-analysis
This meta-analysis of 15 randomized controlled trials involving 2,226 elderly patients found no statistically significant reduction in postoperative delirium with remimazolam. Remimazolam may reduce early postoperative cognitive dysfunction, remifentanil consumption, and perioperative hypotension or bradycardia, but additional well-designed trials are needed.
Impact: The study separates the effects of remimazolam on postoperative delirium from those on early postoperative cognitive dysfunction, preventing an overly broad interpretation of neurocognitive benefit. Its negative delirium result is clinically important because it challenges assumptions that favorable hemodynamics automatically translate into lower delirium risk.
Clinical Implications: Remimazolam may be a reasonable anesthetic option for older patients at risk of hypotension or bradycardia and may reduce opioid requirements. It should not currently be selected specifically for prevention of postoperative delirium, and cognitive outcomes should be monitored using standardized assessments.
Key Findings
- Fifteen randomized controlled trials involving 2,226 patients were included.
- Remimazolam was not associated with a statistically significant reduction in postoperative delirium on postoperative days 1 or 3, or in delirium duration or subtype.
- Remimazolam may reduce early postoperative cognitive dysfunction, intraoperative remifentanil consumption, and perioperative hypotension and bradycardia.
Methodological Strengths
- Systematic review and meta-analysis restricted to randomized controlled trials
- Assessment of multiple clinically relevant outcomes, including delirium, cognitive dysfunction, opioid consumption, and hemodynamic complications
Limitations
- The included trials may have differed in anesthetic protocols, delirium assessment methods, cognitive testing, and follow-up timing.
- The possible reduction in early postoperative cognitive dysfunction requires confirmation because the pooled evidence may be affected by study heterogeneity and limited long-term follow-up.
Future Directions: Future multicenter randomized trials should use standardized delirium and cognitive assessments, prespecified long-term follow-up, and stratification by baseline frailty, preexisting cognitive impairment, and surgical risk.
BACKGROUND: Postoperative neurocognitive disorder (PND), including postoperative delirium (POD) and postoperative cognitive dysfunction (POCD), are prevalent and debilitating complications in elderly surgical patients. Remimazolam, a novel ultra-short-acting benzodiazepine with favorable hemodynamic and sedative properties, has not been fully evaluated for its impact on PND. METHOD: This systematic review and meta-analysis included studies retrieved from PubMed, Embase, Web of Science, and Cochrane library up to February 2026. Eligible studies compared remimazolam with other sedatives in elderly surgical patients and reported POD or POCD incidence. The primary outcome was the incidence of POD/POCD; secondary outcomes included postoperative MMSE scores, intraoperative opioids consumption, duration of post-anesthesia care unit (PACU) and hospital stay, and perioperative complications. RESULTS: Fifteen randomized controlled trials (RCTs) involving 2,226 patients were analyzed. Remimazolam was not statistically associated with reduction in POD incidence on postoperative days 1 or 3, nor did it affect delirium subtypes or duration. However, remimazolam may be associated with a reduced risk of early POCD on days 1, 3, and 5. Remimazolam reduced intraoperative remifentanil consumption and the incidence of perioperative hemodynamic complications.