Daily Anesthesiology Research Analysis
Analyzed 93 papers and selected 3 impactful papers.
Summary
Across perioperative care, three high-impact studies advance actionable strategies. A meta-regression of 99 RCTs shows exercise prehabilitation likely reduces postoperative complications and length of stay, with inspiratory muscle training emerging as a credible effect modifier. An instrumental variable analysis of 1.5 million joint arthroplasties associates perioperative dexamethasone with fewer major complications, and a network meta-analysis finds noninvasive respiratory support for preoxygenation improves oxygenation during emergency intubation versus conventional oxygen.
Research Themes
- Perioperative optimization and enhanced recovery
- Bias-resistant real-world evidence for anesthetic adjuncts
- Airway management and preoxygenation in critical care
Selected Articles
1. Pooled Efficacy and Exploration of Effect Modifiers of Exercise Prehabilitation: A Systematic Review and Meta-regression Analysis of Randomized Controlled Trials.
This registered systematic review and meta-regression of 99 RCTs (n=8,222) found that exercise prehabilitation likely reduces postoperative complications (OR 0.54) and length of stay (−0.90 days). Inspiratory muscle training was the only consistent effect modifier enhancing both outcomes. The authors call for multicenter IPD meta-analyses to refine optimal program, participant, and procedural characteristics.
Impact: Provides high-level evidence across procedures that supports incorporating structured exercise prehabilitation—especially inspiratory muscle training—into perioperative pathways. It bridges heterogeneous literature with a rigorous meta-regression to inform program design.
Clinical Implications: Integrate exercise prehabilitation—prioritizing inspiratory muscle training—into ERAS pathways to reduce complications and hospital stay, while standardizing reporting and aiming for multicenter implementation. Tailored programs should be considered, but routine bridging across surgeries is reasonable.
Key Findings
- Across 99 RCTs (n=8,222), prehabilitation likely reduced postoperative complications (OR 0.54, 95% CI 0.44–0.67; moderate certainty).
- Length of stay decreased by a pooled mean of 0.90 days (95% CI −1.23 to −0.58; low certainty; I2=78%).
- Inspiratory muscle training was the only consistent effect modifier enhancing both complication reduction (OR 0.65) and LOS reduction (MD −1.04 days).
Methodological Strengths
- Registered protocol with a priori hypotheses (CRD42023487683) and duplicate screening
- Random-effects meta-analysis with meta-regression to explore effect modifiers
Limitations
- Heterogeneity for length of stay (I2=78%) and variable trial reporting quality
- Overall certainty ranged from low to moderate; potential publication and performance bias
Future Directions: Conduct well-reported multicenter RCTs and IPD meta-analyses to pinpoint optimal prehabilitation components, timing, and patient subgroups; evaluate implementation and cost-effectiveness.
BACKGROUND: Low certainty evidence supports exercise prehabilitation's efficacy in reducing complications and length of stay in specific populations. Identification of procedural, participant, and program characteristics associated with greater prehabilitation efficacy is required to optimize effective application of prehabilitation programs. Our objectives were to (1) estimate the pooled efficacy of all approaches to exercise prehabilitation across all procedures, participants, and programs in reducing postoperative complications and length of stay, and (2) identify program, participant, and procedural characteristics associated with greater efficacy of exercise prehabilitation. METHODS: A peer-reviewed search strategy was applied to Ovid Medline, Embase, CINAHL, PsycINFO, Web of Science, and the Cochrane CENTRAL Register of Controlled Trials (inception to March 1, 2022, and updated on October 25, 2023, and April 10, 2024). Randomized controlled trials addressing a population of adults (≥18 years) undergoing major elective surgery where participants were allocated to an exercise prehabilitation intervention were included. A multistage review of 6675 citations and 1220 full texts was completed independently in duplicate using DistillerSR. Data were pooled using random effects pairwise meta-analyses and meta-regression. Certainty of evidence and credibility of effect modifiers were evaluated. Critical outcomes were postoperative length of stay and the incidence of postoperative complications. Effect modifiers and hypotheses were identified a priori and published in the study's registered protocol (CRD42023487683). RESULTS: Across 99 included trials (n = 8222), pooled data suggested that exercise prehabilitation likely reduces complication rates (odds ratio [OR] = 0.54; 95% confidence interval [CI], 0.44-0.67; P < .01; I2 = 45%; moderate certainty) and length of stay (mean difference = -0.90 days; 95% CI, -1.23 to -0.58; P < .01; I2 = 78%; low certainty). Inspiratory muscle training was the only significant effect modifier for greater efficacy of exercise prehabilitation in reducing both complications (OR = 0.65; 95% CI, 0.44-0.97; low certainty) and length of stay (MD = -1.04; 95% CI, -1.75 to -0.32; low certainty). No other prespecified procedural, participant, or program factors were consistent or credible effect modifiers. CONCLUSIONS: Exercise prehabilitation may reduce complications and LoS; however, well-reported multicenter trials synthesized using individual participant data are required to identify procedural, participant, and program factors associated with optimal exercise prehabilitation efficacy.
2. Association of Perioperative Dexamethasone With Postoperative Complications After Primary Total Joint Arthroplasty: An Instrumental Variable Analysis.
Using surgeon- and hospital-level prescribing as instruments in 1,525,844 primary TJAs, perioperative dexamethasone exposure was associated with a ~1.2% absolute reduction in 90-day major medical complications. Results were robust across instruments with strong F-statistics and significant Hausman tests; mortality effects were not supported.
Impact: Delivers bias-resistant real-world evidence supporting a common anesthetic adjunct with broad perioperative relevance, reconciling prior inconsistent RCT findings by focusing on composite outcomes and high-risk subgroups.
Clinical Implications: Consider routine perioperative dexamethasone in primary TJA pathways to reduce composite medical complications, while monitoring for context-specific risks. Future trials should target high-risk cohorts and composite endpoints to validate causal effects.
Key Findings
- Instrumental variable analyses (surgeon- and hospital-level instruments) showed ~1.2% absolute reduction in 90-day major medical complications after TKA and THA.
- Robustness supported by high F-statistics and significant Hausman tests; findings aligned with multivariable and bivariate results.
- No consistent effect on mortality; secondary outcomes (infection, readmission) generally mirrored primary findings.
Methodological Strengths
- Use of two independent instruments (surgeon and hospital prescribing patterns) with strong instrument strength
- Very large national cohort and LASSO-informed covariate selection to mitigate confounding
Limitations
- Observational design with residual confounding possible despite IVA
- Generalizability outside TJA and dosing/timing heterogeneity not fully captured
Future Directions: Prospective multicenter RCTs focusing on high-risk subgroups and composite outcomes, with standardized dexamethasone dosing to confirm causality and optimize protocols.
BACKGROUND: Retrospective studies suggest that dexamethasone may provide benefits that extend beyond its antiemetic properties, including a reduction in postoperative complications. However, results from randomized controlled trials have not consistently shown there to be a reduction in composite major adverse events. This discrepancy may be due to confounding factors, measurement error, or simultaneity bias among retrospective investigations. This study used instrumental variable analysis (IVA) to help address potential sources of bias and better estimate treatment effects in patients undergoing total joint arthroplasty (TJA). METHODS: Patients who underwent primary elective TJA between 2016 and 2021 were identified using diagnosis and procedural codes. Bivariate regression, multivariable regression, and IVA were conducted. The primary end point was a 90-day composite (any versus none) of major postoperative medical complications. Secondary outcomes were infection, readmission, and death. Two distinct instruments-the frequency of dexamethasone use by surgeon and by hospital-were used to evaluate the robustness of our IVA. Patient demographics, hospital factors, and comorbidities were reported using descriptive statistics. Instrumental variable covariates were selected using the least absolute shrinkage and selection operator with 3 regularization parameter strategies. RESULTS: 1525,844 TJAs performed between 2015 and 2021 were identified (976,996 knees [total knee arthroplasty {TKA}]; 548,848 hips [total hip arthroplasty {THA}]). Major postoperative medical complications were observed in 31,299 (3.43%) dexamethasone-exposed patients compared to 31,266 (4.87%) unexposed patients. Surgeon-based IVA yielded results comparable to the multivariable and bivariate analysis (local average treatment effect [LATE]: TKA: -1.20% [95% confidence interval [CI], -1.33% to -1.08%]; THA: -1.14% [95% CI, -1.30% to -0.99%]). Hospital-based IVA produced similar findings (LATE: TKA: -1.23% [95% CI, -1.38% to -1.09%]; THA: -1.18% [95% CI, -1.35% to -1.00%]). Both instruments demonstrated high F-statistics and significant Hausman tests. Secondary outcomes mirrored these results, except for mortality, which did not meet endogeneity criteria across analyses. CONCLUSIONS: The findings of this study support that dexamethasone exposure is associated with a reduction in composite major postoperative complications after TJA. The observed moderate treatment effect, in conjunction with a low baseline incidence of adverse events, may explain the inconsistent outcomes reported in previous randomized trials. Future prospective studies should incorporate composite end points and target high-risk patient populations or procedural subgroups.
3. Noninvasive respiratory support for preoxygenation in emergency intubation: a systematic review and network meta-analysis.
In 15 RCTs (n=2,939), noninvasive respiratory support strategies for preoxygenation (HFOT/NIV) improved nadir oxygen saturation compared with conventional oxygen therapy during emergency intubation. Although certainty was low, findings consistently favored NRS.
Impact: Addresses a high-stakes airway management question with a comparative effectiveness framework, supporting broader adoption of NRS preoxygenation to mitigate periprocedural desaturation.
Clinical Implications: Prefer HFOT or NIV for preoxygenation in emergency intubation of critically ill adults to improve nadir SpO2 versus conventional oxygen, with local protocols addressing device availability, staff proficiency, and monitoring.
Key Findings
- Network meta-analysis of 15 RCTs (n=2,939) showed all NRS modalities improved lowest recorded SpO2 compared with conventional oxygen therapy.
- Benefits were consistent across trials despite overall low certainty of evidence.
- Findings support NRS as preferred preoxygenation strategies in emergency intubation of critically ill adults.
Methodological Strengths
- PROSPERO-registered systematic review with network meta-analysis enabling indirect comparisons
- Restriction to randomized trials enhances internal validity
Limitations
- Overall low certainty and potential heterogeneity in patient severity, devices, and preoxygenation protocols
- Incomplete reporting across some trials limits granular subgroup inference
Future Directions: Head-to-head multicenter RCTs comparing HFOT versus NIV, standardized protocols, and patient-centered outcomes (hypoxemia, intubation success, safety) to refine best practice.
BACKGROUND: The benefits of preoxygenation with noninvasive respiratory support (NRS), including high-flow oxygen therapy (HFOT) and noninvasive ventilation (NIV), compared to conventional oxygen therapy (COT) during emergency endotracheal intubation (ETI) remain unclear. This network meta-analysis aims to evaluate whether preoxygenation with NRS is more effective than COT in minimising the lowest recorded peripheral capillary oxygen saturation ( METHODS: A comprehensive literature search was conducted (PROSPERO-CRD42024606842) across Medline, Embase and Scopus. The PICOS criteria were: P: critically ill adult patients requiring emergency ETI; I: randomisation for receiving preoxygenation with NRS; C: randomisation for COT; O: the lowest recorded RESULTS: 15 RCTs (2939 patients) met the inclusion criteria. Compared to COT, all NRS methods improved the lowest INTERPRETATION: During emergency ETI in critical care areas, despite a low certainty of evidence, preoxygenation with NRS overperformed COT in maintaining