Daily Anesthesiology Research Analysis
Analyzed 29 papers and selected 3 impactful papers.
Summary
The most impactful studies addressed individualized anesthetic risk stratification, weight-adjusted sedative dosing, and environmentally sustainable anesthesia delivery. A large multicenter pediatric registry identified underweight status as a marker for desaturation and difficult first-pass intubation, while a randomized trial found that ideal-body-weight remimazolam dosing reduced respiratory depression compared with total-body-weight dosing.
Research Themes
- Pediatric airway safety and risk stratification
- Weight-adjusted sedative dosing and respiratory safety
- Environmental sustainability in inhalational anesthesia
Selected Articles
1. Comparison of total versus ideal body weight-based remimazolam dosing for sedation in overweight and obese patients undergoing knee arthroplasty under spinal anesthesia: a randomized controlled trial.
In a patient- and outcome assessor-blinded randomized trial of 110 overweight or obese patients, total-body-weight-based remimazolam caused more respiratory depression than ideal-body-weight-based dosing. Among 102 analyzed patients, respiratory depression occurred in 45.1% versus 25.5%, and recovery was prolonged by a median of 5 minutes with total-body-weight dosing.
Impact: This study directly addresses a common dosing problem in procedural sedation and provides randomized evidence supporting ideal-body-weight dosing to reduce respiratory compromise in patients with overweight or obesity. The findings are clinically actionable but require confirmation across procedures, sedation depths, and dosing protocols.
Clinical Implications: For overweight and obese patients receiving remimazolam sedation under spinal anesthesia, clinicians should consider ideal body weight rather than total body weight for initial dosing and infusion calculations, with enhanced respiratory monitoring and cautious titration. Further dose-finding studies are needed before defining a universal regimen.
Key Findings
- Respiratory depression occurred more frequently with total-body-weight dosing than with ideal-body-weight dosing: 45.1% versus 25.5% (relative risk 1.77, P = .038).
- Total-body-weight dosing was associated with a median 5-minute prolongation of recovery.
- Total-body-weight dosing, older age, and male sex were independent risk factors for respiratory depression.
- Pharmacokinetic/pharmacodynamic simulations generally underestimated sedation depth, supporting cautious clinical titration.
Methodological Strengths
- Patient- and outcome assessor-blinded randomized controlled design.
- Assessment of both clinical outcomes and pharmacokinetic/pharmacodynamic simulations.
Limitations
- The analyzed sample included 102 patients from a specific surgical and sedation context.
- The estimated safer loading dose was exploratory and was not prospectively validated.
Future Directions: Prospective dose-finding studies should evaluate ideal-body-weight algorithms across BMI ranges, age groups, procedural settings, and sedation targets, while incorporating continuous respiratory monitoring and pharmacokinetic validation.
BACKGROUND: Obesity poses sedation challenges owing to altered pharmacokinetics. However, the optimal weight scalar for remimazolam administration in overweight and obese patients remains controversial. This study compared the efficacy and safety of total body weight (TBW)- vs. ideal body weight (IBW)-based remimazolam dosing. METHODS: In this patient- and outcome assessor-blinded randomized trial, 110 patients of body mass index (BMI) ≥ 25 kg/m2 undergoing elective knee arthroplasty under spinal anesthesia received TBW- or IBW-based remimazolam.
2. Association Between Extreme Weight-for-Age and Airway-Related Adverse Events During Anesthesia Induction: An Analysis Using the J-PEDIA Registry Data.
This multicenter retrospective cohort study analyzed 18,835 pediatric airway encounters from 12 tertiary hospitals. Although no weight category was associated with airway-related adverse events overall, obesity and underweight status were associated with oxygen desaturation, and underweight status was associated with lower first-attempt tracheal intubation success.
Impact: The study provides unusually large, multicenter pediatric anesthesia data that distinguish overall airway adverse events from clinically important desaturation and first-pass intubation success. It supports extreme body weight, particularly underweight status, as a practical pre-induction risk marker rather than assuming obesity is the only high-risk phenotype.
Clinical Implications: Pediatric patients with underweight or obesity may warrant enhanced preoxygenation, continuous pulse oximetry vigilance, preparation for difficult airway management, and individualized intubation planning. Underweight children may particularly benefit from first-pass optimization and early escalation strategies, although the observational design does not establish causality.
Key Findings
- The analysis included 18,835 airway management encounters from 12 tertiary hospitals.
- Airway-related adverse events occurred in 2.8% of underweight, 2.0% of normal-weight, 1.9% of obese, and 1.6% of overweight encounters, with no evidence of an overall weight-category association.
- Obesity and underweight status were associated with oxygen desaturation of at least 10%: adjusted odds ratios 2.12 and 1.31, respectively.
- Underweight status was associated with lower first-attempt tracheal intubation success: adjusted odds ratio 0.69.
Methodological Strengths
- Large multicenter registry-based cohort with 18,835 pediatric encounters.
- Multilevel mixed-effects regression accounted for potential confounding and clustering by institution.
Limitations
- The retrospective observational design permits association but not causal inference.
- The registry analysis may not capture all airway-management practices, operator-level factors, or unmeasured illness severity.
- The study assessed induction encounters rather than longer-term clinical outcomes.
Future Directions: Prospective studies should validate weight-based risk prediction models, examine mechanisms underlying desaturation in underweight children, and test whether targeted preoxygenation, equipment selection, or first-pass optimization improves outcomes.
BACKGROUND: Children are particularly vulnerable to hypoxia during airway management, which can lead to life-threatening complications. However, pediatric evidence quantifying the association between body weight range and airway management-related adverse events (ARAEs) during anesthesia induction remains limited. This study aimed to evaluate the association between body weight and incidence of adverse events during general anesthesia induction. METHODS: This multicenter retrospective cohort study used data from the Japanese Pediatric Difficult Airway Registry from June 2022 to February 2025 across 12 tertiary care hospitals. All airway management encounters (from the initiation of preoxygenation to successful tracheal intubation) during the initial induction of general anesthesia in children aged <18 years who underwent tracheal intubation during the study period were included.
3. Utilization and Estimation of Environmental Impact of End-Tidal Control in a Multisite Academic Health System: A Retrospective Observational Cross-Sectional Study.
In 12,818 adult general anesthetics across a multisite academic health system, end-tidal control was used in 52.7% of cases. Compared with nonuse, end-tidal control was associated with a 1.14 L/min lower median fresh gas flow, 5.23 mL/h lower sevoflurane consumption, and 1.06 kg lower carbon dioxide-equivalent emissions per hour of maintenance.
Impact: This study translates sustainability benefits from smaller trials into real-world, large-scale anesthesia practice and identifies substantial clinician-level variation in adoption. It links a specific anesthesia technology with measurable reductions in volatile anesthetic use and greenhouse-gas emissions without requiring new operating-room infrastructure.
Clinical Implications: End-tidal control can be considered as part of institutional strategies for low-flow anesthesia and environmental sustainability. Implementation should include clinician education, standardized protocols, monitoring of patient selection and safety, and attention to workflow factors that appear to drive substantial variation in use.
Key Findings
- End-tidal control was used in 6,755 of 12,818 anesthetics (52.7%).
- In-room clinicians explained 38.5% of the variation in end-tidal control use, compared with 3.9% attributable to the attending anesthesiologist.
- End-tidal control was associated with a 1.14 L/min reduction in median fresh gas flow and a 5.23 mL/h reduction in sevoflurane consumption.
- Carbon dioxide-equivalent emissions decreased by 1.06 kg per hour of anesthesia maintenance, and median fresh gas flow was reduced by 62.3%.
Methodological Strengths
- Large real-world dataset spanning multiple sites within an academic health system.
- Multilevel mixed-effects modeling quantified both clinical utilization factors and environmental outcomes.
Limitations
- The retrospective observational design cannot establish that end-tidal control caused the observed reductions.
- The study was conducted within one academic health system and may not generalize to other institutions or anesthesia machines.
- Patient outcomes and potential safety trade-offs were not the primary focus.
Future Directions: Prospective implementation studies should evaluate patient safety, anesthetic performance, cost, clinician training, and emissions across diverse hospitals. Cluster-randomized or stepped-wedge designs could clarify causal environmental and operational benefits.
BACKGROUND: End-tidal control (ETC) is a technology new to the United States that enables automated titration of anesthetic gases while using low-flow anesthesia. Although previous, smaller clinical trials have demonstrated that ETC use leads to reductions in fresh gas flow (FGF), anesthetic agent consumptions, and carbon dioxide equivalents (CO2 equivalents) per hour of maintenance, there is limited information about large-scale deployment of ETC including detailed case information and real-world impact in a large academic health system. We sought to describe the utilization of ETC and quantify the impact of ETC utilization on FGF, sevoflurane consumption, and CO2 equivalents per hour of maintenance of anesthesia. METHODS: Data were obtained from an electronic health record-derived registry for adult patients receiving general anesthesia between April 1, 2023, and September 30, 2024, on an anesthesia machine with ETC available at University of Michigan Health-Ann Arbor locations.