Daily Anesthesiology Research Analysis
Three impactful anesthesiology-related studies emerged today: (1) a large multicenter cohort identified modifiable operating room practice variation associated with postoperative acute kidney injury after cardiac surgery; (2) a meta-analysis found inconsistent effects of intraoperative dexmedetomidine on cancer outcomes, with RCTs suggesting improved recurrence-free survival but retrospective studies showing reduced overall survival; (3) a nationwide claims study showed no clinically meaningful
Summary
Three impactful anesthesiology-related studies emerged today: (1) a large multicenter cohort identified modifiable operating room practice variation associated with postoperative acute kidney injury after cardiac surgery; (2) a meta-analysis found inconsistent effects of intraoperative dexmedetomidine on cancer outcomes, with RCTs suggesting improved recurrence-free survival but retrospective studies showing reduced overall survival; (3) a nationwide claims study showed no clinically meaningful reduction in chronic opioid use with peripheral nerve blocks after total knee arthroplasty.
Research Themes
- Perioperative kidney protection in cardiac surgery
- Onco-anesthesiology and perioperative immunomodulation
- Opioid stewardship and regional anesthesia outcomes
Selected Articles
1. Hospital and Clinician Practice Variation in Cardiac Surgery and Postoperative Acute Kidney Injury.
In a 23,389-patient multicenter cohort, hospital- and clinician-level operating room practices varied substantially. Higher hospital inotrope infusion rates were associated with increased AKI, while higher clinician-level RBC transfusion rates were associated with lower AKI; other practice variations showed no association.
Impact: Identifies modifiable intraoperative practice patterns linked to AKI after cardiac surgery, providing actionable targets for quality improvement.
Clinical Implications: Standardizing intraoperative hemodynamic strategies, particularly cautious inotrope use, and reassessing transfusion thresholds may reduce AKI risk. Multilevel benchmarking across hospitals and clinicians can guide targeted interventions.
Key Findings
- Substantial variation in inotrope, vasopressor, transfusion, and fluid practices across hospitals and clinicians (ICCs up to 44.5%).
- Higher hospital-level inotrope infusion rates associated with increased AKI (AOR 1.98, 95% CI 1.18-3.33).
- Higher clinician-level RBC transfusion rates associated with lower AKI (AOR 0.89, 95% CI 0.79-0.99).
Methodological Strengths
- Large multicenter cohort with integrated clinical and registry data (n=23,389).
- Multilevel mixed-effects modeling adjusting for patient-level confounders and quantifying variation via ICCs.
Limitations
- Observational design cannot establish causality; residual confounding may persist.
- Practice measures are proxies (e.g., duration thresholds) and may not capture dose-response or timing nuances.
Future Directions: Prospective interventional trials and implementation studies should test standardized inotrope strategies and transfusion protocols to reduce AKI.
IMPORTANCE: Approximately 30% of US patients develop acute kidney injury (AKI) after cardiac surgery, which is associated with increased morbidity, mortality, and health care costs. The variation in potentially modifiable hospital- and clinician-level operating room practices and their implications for AKI have not been rigorously evaluated. OBJECTIVE: To quantify variation in clinician- and hospital-level hemodynamic and resuscitative practices during cardiac surgery and identify their associations with AKI. DESIGN, SETTING, AND PARTICIPANTS: This cohort study analyzed integrated hospital, clinician, and patient data extracted from the Multicenter Perioperative Outcomes Group dataset and the Society of Thoracic Surgeons Adult Cardiac Surgical Database. Participants were adult patients (aged ≥18 years) who underwent cardiac surgical procedures between January 1, 2014, and February 1, 2022, at 8 geographically diverse US hospitals. Patients were followed up through March 2, 2022. Statistical analyses were performed from October 2024 to February 2025. EXPOSURES: Hospital- and clinician-level variations in operating room hemodynamic practices (inotrope infusion >60 minutes and vasopressor infusion >60 minutes) and resuscitative practices (homologous red blood cell [RBC] transfusion and total fluid volume administration). MAIN OUTCOMES AND MEASURES: The primary outcome was consensus guideline-defined AKI (any stage) within 7 days after cardiac surgery. Hospital- and clinician-level variations were quantified using intraclass correlation coefficients (ICCs). Associations of hospital- and clinician-level practices with AKI were analyzed using multilevel mixed-effects models, adjusting for patient-level characteristics. RESULTS: Among 23 389 patients (mean [SD] age, 63 [13] years; 16 122 males [68.9%]), 4779 (20.4%) developed AKI after cardiac surgery. AKI rates varied across hospitals (median [IQR], 21.7% [15.5%-27.2%]) and clinicians (18.1% [10.1%-23.7%]). Significant clinician- and hospital-level variation existed for inotrope infusion (ICC, 6.2% [95% CI, 4.2%-8.0%] vs 17.9% [95% CI, 3.3%-31.9%]), vasopressor infusion (ICC, 11.7% [95% CI, 8.3%-14.9%] vs 44.5% [95% CI, 11.7%-63.5%]), RBC transfusion (ICC, 1.7% [95% CI, 0.9%-2.6%] vs 4.5% [95% CI, 1.2%-9.4%]), and fluid volume administration (ICC, 2.1% [95% CI, 1.3%-2.7%] vs 23.8% [95% CI, 2.7%-39.9%]). In multilevel risk-adjusted models, the AKI rate was higher for patients at hospitals with higher inotrope infusion rates (adjusted odds ratio [AOR], 1.98; 95% CI, 1.18-3.33; P = .01) and lower among clinicians with higher RBC transfusion rates (AOR, 0.89; 95% CI, 0.79-0.99; P = .03). Other practice variations were not associated with AKI. CONCLUSIONS AND RELEVANCE: This cohort study of adult patients found that hospital- and clinician-level variation in operating room practices was associated with AKI after cardiac surgery, suggesting possible targets for intervention.
2. Effect of intraoperative dexmedetomidine on prognosis in patients with cancer undergoing surgical procedures: a systematic review and meta-analysis.
This meta-analysis of 12 studies found discordant signals: RCTs suggested improved recurrence-free survival with intraoperative dexmedetomidine, whereas retrospective studies indicated reduced overall survival and no RFS benefit. Evidence remains insufficient to guide practice change.
Impact: Addresses a critical onco-anesthesiology question with direct implications for intraoperative drug selection and long-term cancer outcomes.
Clinical Implications: Given conflicting evidence, routine use of dexmedetomidine solely to improve oncologic outcomes is not supported. Clinicians should individualize its use based on hemodynamic and analgesic benefits while awaiting definitive RCTs.
Key Findings
- Included 12 studies: 6 RCTs and 6 retrospective cohorts.
- RCTs: no significant effect on overall survival (OR 0.87) but improved recurrence-free survival (OR 0.65).
- Retrospective studies: decreased overall survival (post-matching HR 1.52) and no significant effect on recurrence-free survival.
Methodological Strengths
- Comprehensive search across major databases with dual-review extraction.
- Study design-specific quality assessment (Cochrane for RCTs, NOS for retrospectives).
Limitations
- Heterogeneity across tumor types, perioperative protocols, dosing, and follow-up.
- Mixing RCTs and observational studies with differing biases complicates inference; potential confounding by indication in retrospective data.
Future Directions: Large, tumor-specific, pre-registered RCTs with standardized dosing and long-term follow-up should evaluate oncologic outcomes and mechanistic biomarkers under dexmedetomidine.
BACKGROUND: Cancer places a significant burden on patients and healthcare systems. Dexmedetomidine, an α METHODS: We conducted a comprehensive search of PubMed, Web of Science, Embase, and the China National Knowledge Infrastructure up to April 2024. Two researchers extracted data including authors, year, country, study design, follow-up, patient characteristics, and hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival and recurrence-free survival. Quality assessment was conducted using the Cochrane tool for randomised controlled trials (RCTs) and the Newcastle-Ottawa Scale for retrospective studies. RESULTS: The review identified 12 studies: six RCTs and six retrospective studies. In the RCTs, intraoperative dexmedetomidine showed no significant effect on overall survival (odds ratio [OR] 0.87, 95% CI 0.67-1.13, P=0.29) but improved recurrence-free survival (OR 0.65, 95% CI 0.47-0.91, P=0.01). Retrospective studies indicated that dexmedetomidine was associated with decreased overall survival (post-matching HR 1.52, 95% CI 1.15-2.00, P=0.003), and had no significant effect on recurrence-free survival (post-matching HR 1.29, 95% CI 0.96-1.72, P=0.09). CONCLUSIONS: Meta-analysis reveals inconsistent evidence regarding impact of intraoperative dexmedetomidine on cancer outcomes after surgery. RCTs suggest improved recurrence-free survival, whereas retrospective studies suggest potential reductions in overall survival. The limited and contradictory data highlight the necessity for more high-quality RCTs to clarify the effects of dexmedetomidine on survival and prognosis in this population.
3. Impact of peripheral nerve blocks on chronic opioid use after elective total knee arthroplasty from a large US claims database.
In 126,860 TKAs, peripheral nerve blocks—single-shot or continuous—did not reduce chronic opioid dependence and were associated with only trivial increases in chronic opioid use. No clinically meaningful differences were observed between PNB modalities.
Impact: Provides large-scale, real-world evidence informing expectations of regional anesthesia on long-term opioid outcomes after TKA.
Clinical Implications: Peripheral nerve blocks should continue to be used for perioperative analgesia, but clinicians should not expect reductions in chronic opioid use; comprehensive multimodal strategies and prescribing stewardship remain essential.
Key Findings
- Among 126,860 TKAs, chronic opioid dependence rates were 0.7% (no PNB), 0.8% (single-shot), 0.9% (continuous).
- Chronic opioid use between days 90–180 was 12.6% (no PNB), 13.8% (single-shot), 14.3% (continuous).
- Multivariable models showed no association with chronic opioid dependence and only marginally higher odds of chronic opioid use with PNB (OR 1.01).
Methodological Strengths
- Very large, contemporary nationwide claims dataset with clear operational definitions for outcomes.
- Adjustment for confounders using multivariable modeling and comparison across PNB modalities.
Limitations
- Claims data lack granular clinical details (e.g., pain scores, block quality, adjuvants) and may have coding biases.
- Residual confounding and selection bias (indication for PNB) cannot be fully excluded.
Future Directions: Prospective registries integrating patient-reported outcomes, prescription data, and block characteristics should evaluate long-term analgesic trajectories.
BACKGROUND: Peripheral nerve blocks (PNBs), either single-shot injection or continuous catheter infusion, are increasingly used in total knee arthroplasties (TKAs). Although recent data show equivalence between both modalities in immediate perioperative analgesia, comparative data on longer-term outcomes such as chronic opioid use are scarce. METHODS: Using US Merative MarketScan commercial claims data (2018-22; n=126 860 TKAs), we compared: (1) patients receiving PNB vs those who did not; and (2) single-shot vs continuous catheter infusion PNB. Primary outcomes were: (1) 'chronic opioid dependence' (>120 pills of opioids prescribed or >10 prescriptions between postoperative day 90 and 180); and (2) 'chronic opioid use' (any opioid refill between postoperative day 90 and 180). Multivariable models measured associations between PNB modalities and outcomes. RESULTS: Incidence of 'chronic opioid dependence' was 0.7%, 0.8%, and 0.9% among patients without PNB, with single-shot PNB, and with continuous PNB, respectively. For 'chronic opioid use', this was 12.6%, 13.8%, and 14.3%. Multivariable analyses indicated no association between PNB (yes/no and modality) utilisation and 'chronic opioid dependence'. However, single-shot (OR 1.01, 95% CI 1.01-1.02; P<0.001) and continuous PNB (OR 1.01, 95% CI 1.01-1.02; P<0.001) compared with no PNB use were associated with slightly higher odds of 'chronic opioid use'. DISCUSSION: Our results did not show any clinically meaningful differences in postoperative chronic opioid use or dependence across patients receiving single-shot PNB or continuous PNB treatment. Future prospective registry data might be indicated to further address this question.