Daily Anesthesiology Research Analysis
A large multicenter randomized trial found that Bispectral Index (BIS)-guided anesthesia did not reduce 1-year mortality or 30-day complications in older adults undergoing noncardiac surgery, challenging routine BIS use for outcome improvement. Two high-quality observational studies highlighted rapidly increasing perioperative use of medications for opioid use disorder (MOUD) and the strong association between socioeconomic deprivation and worse postoperative outcomes, emphasizing the need for g
Summary
A large multicenter randomized trial found that Bispectral Index (BIS)-guided anesthesia did not reduce 1-year mortality or 30-day complications in older adults undergoing noncardiac surgery, challenging routine BIS use for outcome improvement. Two high-quality observational studies highlighted rapidly increasing perioperative use of medications for opioid use disorder (MOUD) and the strong association between socioeconomic deprivation and worse postoperative outcomes, emphasizing the need for guideline development and equity-focused preoperative optimization.
Research Themes
- Depth-of-anesthesia monitoring and hard outcomes
- Perioperative management of patients on MOUD
- Social determinants of surgical outcomes
Selected Articles
1. Bispectral Index-guided Anesthesia for Older Patients Having Noncardiac Surgery: A Randomized Multicenter Trial.
In 6,982 older adults undergoing elective noncardiac surgery, BIS-guided titration did not reduce 1-year mortality or 30-day complications versus routine care, and average BIS values were nearly identical between groups. Findings suggest clinicians already titrate anesthetic depth adequately without BIS guidance for outcome improvement.
Impact: This is a large, double-blind, multicenter RCT addressing a long-standing question about depth-of-anesthesia monitoring and hard outcomes, with direct implications for guideline recommendations and resource use.
Clinical Implications: Routine BIS monitoring to improve mortality or major complications in older adults undergoing noncardiac surgery is not supported; BIS may be reserved for specific indications (e.g., TIVA awareness risk, paralyzed cases) rather than universal use for outcome improvement.
Key Findings
- One-year all-cause mortality was 10.2% (BIS-guided) vs 10.0% (routine); HR 1.02 (95% CI 0.88–1.17; P=0.812).
- 30-day moderate-to-severe complications were 10.4% vs 10.6%; RR 0.99 (95% CI 0.85–1.16; P=0.938).
- Mean BIS values were similar (47 vs 46), indicating comparable hypnotic depth despite protocolized BIS guidance.
Methodological Strengths
- Multicenter, double-blind randomized design with robust primary endpoint (1-year mortality).
- Large sample size (n=6,982) with CONSORT-style reporting and clinically relevant secondary outcomes.
Limitations
- Conducted in a single country; generalizability to other health systems and practices may vary.
- Minimal separation in achieved BIS values between groups may limit the ability to detect effects of deeper/light anesthesia targets.
Future Directions: Identify subgroups (e.g., high frailty, cognitive vulnerability) that may benefit from EEG-guided strategies; evaluate alternative EEG metrics (e.g., burst suppression control) targeting delirium or cognitive outcomes.
2. Trends in Use of Medications for Opioid Use Disorder among Commercially Insured U.S. Surgical Patients, 2016 to 2022.
In 8.1 million surgical admissions, MOUD use nearly doubled between 2016 and 2022, with buprenorphine accounting for 84% of MOUD prescriptions. Procedures with the highest MOUD prevalence were debridement and several orthopedic procedures, underscoring the urgency of perioperative management guidance for this growing population.
Impact: The scale and temporal trend analysis define the size and distribution of perioperative MOUD exposure, providing essential infrastructure for evidence-based perioperative guidelines and care pathways.
Clinical Implications: Develop and disseminate procedure-specific protocols on MOUD continuation vs. modification, analgesic multimodal strategies, and collaboration with addiction medicine—particularly for orthopedic services where MOUD prevalence is highest.
Key Findings
- Adjusted MOUD prevalence rose from 55.2 to 99.8 per 100,000 procedures (2016–2022), adjusted annual change 16.9/100,000 (95% CI 14.0–19.8).
- Among MOUD users (n=15,701 admissions), buprenorphine comprised 84.0% of agents.
- Highest MOUD rates by procedure: debridement (719.0/100,000), shoulder arthroplasty (579.4/100,000), lower extremity amputation (529.6/100,000), hip/pelvis open fracture repair (497.6/100,000).
Methodological Strengths
- Very large national commercial claims database with adjusted logistic models for temporal trends.
- Procedure-level prevalence estimates across 1,083 surgical categories.
Limitations
- Restricted to commercially insured adults; generalizability to Medicare/Medicaid/uninsured is limited.
- Claims-based data may misclassify MOUD exposure and lack clinical granularity (dose, continuation perioperatively).
Future Directions: Prospective and pragmatic studies comparing continuation vs. temporary hold strategies for MOUD, integration with multimodal analgesia, and inclusion of public payer populations.
3. Social deprivation and morbidity and mortality after surgery: a UK national observational cohort study.
In a UK-wide prospective surgical cohort (n=18,901), higher socioeconomic deprivation (IMD1–2) was associated with increased day-7 morbidity and 30-day in-hospital mortality versus least deprived (IMD5), although associations attenuated after adjusting for preoperative fitness/comorbidity. Findings point to prehabilitation and risk modification opportunities.
Impact: Provides robust, contemporary, national evidence linking deprivation to postoperative outcomes using standardized IMD and mixed-effects modeling, informing equity-focused perioperative policy and resource allocation.
Clinical Implications: Incorporate deprivation-informed risk stratification and targeted preoperative optimization (e.g., prehabilitation, comorbidity control) to mitigate excess risk among deprived populations; consider health-system level interventions to address structural drivers.
Key Findings
- Day-7 postoperative morbidity occurred in 13.7%; IMD1 and IMD2 associated with higher odds vs IMD5 (OR 1.32 and 1.26, respectively).
- 30-day in-hospital mortality was 1.3%; higher in IMD1 and IMD2 (OR 1.90 and 1.75 vs IMD5).
- Associations attenuated after adjusting for preoperative physical status and comorbidities, indicating mediation by baseline health.
Methodological Strengths
- Prospective national cohort (SNAP-2) with standardized deprivation measure (IMD).
- Multivariable mixed-effects logistic modeling adjusting for key confounders.
Limitations
- Observational design limits causal inference; residual confounding likely.
- UK-specific socioeconomic context may limit generalizability to other settings.
Future Directions: Test targeted prehabilitation and optimization pathways for deprived patients; integrate social risk into perioperative risk calculators; evaluate system-level interventions to reduce inequities.