Daily Anesthesiology Research Analysis
Three impactful studies in anesthesiology span mental health prevention, global pharmacoepidemiology, and ventilation physiology. A single-center randomized clinical trial shows intraoperative esketamine reduces postpartum depression after cesarean delivery. A 20-million–pregnancy multinational cohort maps global opioid use in pregnancy, and a post hoc analysis of three trials clarifies how respiratory rate and pressures drive mechanical power in ventilated, non-ARDS patients.
Summary
Three impactful studies in anesthesiology span mental health prevention, global pharmacoepidemiology, and ventilation physiology. A single-center randomized clinical trial shows intraoperative esketamine reduces postpartum depression after cesarean delivery. A 20-million–pregnancy multinational cohort maps global opioid use in pregnancy, and a post hoc analysis of three trials clarifies how respiratory rate and pressures drive mechanical power in ventilated, non-ARDS patients.
Research Themes
- Peripartum mental health prevention with anesthetic adjuncts
- Global opioid utilization patterns in pregnancy
- Mechanical power optimization in protective ventilation
Selected Articles
1. Intraoperative Esketamine and Postpartum Depression Among Women With Cesarean Delivery: A Randomized Clinical Trial.
In a single-center RCT of 308 cesarean deliveries, a single 0.25 mg/kg intraoperative esketamine infusion halved the 6-week postpartum depression incidence versus saline. The effect was assessed by the Edinburgh Postnatal Depression Scale using an intention-to-treat analysis.
Impact: This pragmatic RCT links an intraoperative anesthetic intervention to a meaningful mental health outcome, potentially redefining peripartum care pathways.
Clinical Implications: Intraoperative esketamine may be considered for PPD prevention in cesarean deliveries, with attention to safety, dosing, and patient selection. Larger, multicenter trials should confirm efficacy and assess neonatal and breastfeeding outcomes.
Key Findings
- Esketamine reduced 6-week postpartum depression incidence: 10.4% vs 19.5% (RR 0.53; 95% CI 0.30–0.93; P=.02).
- Intervention: single intraoperative infusion 0.25 mg/kg over 20 minutes versus saline control.
- Randomization 1:1, cesarean population, intention-to-treat analysis at a tertiary center.
Methodological Strengths
- Randomized, controlled, intention-to-treat design with prespecified primary outcome.
- Clinically relevant endpoint (PPD) assessed by a validated scale at a fixed time point.
Limitations
- Single-center study in China may limit generalizability across diverse health systems.
- Short follow-up (6 weeks) and limited safety/neonatal outcomes reporting.
Future Directions: Multicenter, pragmatic RCTs comparing dosing strategies and timing; evaluation of maternal-infant bonding, breastfeeding, neonatal neurobehavior, and cost-effectiveness.
IMPORTANCE: Esketamine has been found to reduce the incidence of postpartum depression (PPD) in randomized clinical trials. However, current evidence from randomized clinical trials does not reflect esketamine's efficacy in clinical settings. OBJECTIVE: To assess the clinical efficacy of intraoperative esketamine administration for preventing PPD among women who underwent cesarean delivery. DESIGN, SETTING, AND PARTICIPANTS: This randomized clinical trial was conducted at The First Affiliated Hospital of Chongqing Medical University in Chongqing, China, from March 2023 to February 2024. Pregnant patients admitted for cesarean delivery were included, while those with intellectual dysfunction or contraindications to esketamine were excluded. All participants were assigned randomly to either the esketamine group or control group in a 1:1 ratio. Data analysis was based on the intention-to-treat principle. INTERVENTIONS: Patients in the esketamine group received an infusion of 0.25 mg/kg esketamine in 20 mL of saline over 20 minutes, whereas patients in the control group received 20 mL saline over 20 minutes. MAIN OUTCOMES AND MEASURES: The primary outcome was the incidence of PPD at 6 weeks post partum. PPD was assessed using the Edinburgh Postnatal Depression Scale. RESULTS: A total of 308 pregnant women were randomly assigned to 1 of 2 groups: esketamine (n = 154; mean [SD] patient age, 31.57 [4.26] years) and control (n = 154; mean [SD] patient age, 32.53 [7.74] years). Incidence of PPD was significantly lower in the esketamine group compared with the control group at 6 weeks post partum (10.4% [16] vs 19.5% [30]; relative risk, 0.53; 95% CI, 0.30-0.93; P = .02). CONCLUSIONS AND RELEVANCE: This randomized clinical trial demonstrated esketamine's advantage in reducing the incidence of PPD at 6 weeks post partum in patients who underwent cesarean delivery. The efficacy and safety of esketamine in preventing PPD warrant further investigation in clinical practice. TRIAL REGISTRATION: Chinese Clinical Trial Registry Identifier: ChiCTR2200065494.
2. Global Trends in Analgesic Opioid Use in Pregnancy: A Retrospective Cohort Study.
Across 20,306,228 pregnancies in 14+ jurisdictions using a harmonized protocol, at least one analgesic opioid prescription/dispensing occurred in 55 per 1,000 pregnancies, with wide geographic variation (UK 4/1,000; US publicly insured 191/1,000). Trends were stable or declining in most settings; codeine and tramadol predominated.
Impact: Provides the most comprehensive, harmonized multinational picture of opioid exposure in pregnancy, informing obstetric anesthesia, prescribing stewardship, and regulatory policy.
Clinical Implications: Clinicians should recognize stark regional differences and prioritize non-opioid analgesia when feasible, especially in high-prevalence contexts. Findings can guide targeted stewardship, counseling, and risk-benefit discussions.
Key Findings
- Among 20,306,228 pregnancies, 55 per 1,000 had at least one opioid dispensing/prescription; UK 4/1,000 vs US publicly insured 191/1,000.
- Largest relative decrease: Hong Kong (PR 0.2; 95% CI 0.1–0.2, 2005–2020); largest increase: Iceland (PR 4.4; 95% CI 3.7–5.2, 2004–2017).
- Codeine and tramadol were among the three most used opioids across most populations; sensitivity analysis (≥2 events) yielded 17 per 1,000.
Methodological Strengths
- Harmonized, common protocol applied across diverse, population-based and payer-linked datasets.
- Very large sample enabling robust estimation of trends and subgroup patterns.
Limitations
- Retrospective dispensing/prescription data lack clinical indication, dosing, and adherence details.
- Heterogeneity across data sources and potential misclassification; no linkage to maternal-fetal outcomes.
Future Directions: Link utilization data to maternal and neonatal outcomes; evaluate stewardship interventions; assess drivers of cross-country variation including policy and payer effects.
BACKGROUND: Pain is common during pregnancy, yet there are few contemporary studies of opioid use in pregnancy. This study aimed to describe prescription analgesic opioid use during pregnancy across four regions: Oceania (New South Wales, Australia, and New Zealand), North America (Ontario, Canada, and United States), Northern Europe (Denmark, Finland, Iceland, Norway, Sweden, and United Kingdom), and East Asia (Hong Kong, South Korea, and Taiwan). METHODS: A common protocol was applied to population-based data to measure analgesic opioid dispensing or prescriptions during pregnancy before birth in 2000 to 2020. The populations captured included those with public and private insurance in the United States, a sample of primary care practices in the United Kingdom, and whole-of-population cohorts in the remainder of the locations. This study examined prevalence of use, defined as at least one dispensing or prescribing and estimated trends over time. Use by sociodemographic and pregnancy characteristics is described. RESULTS: Among a total of 20,306,228 pregnancies, 1,115,853 (55 per 1,000) had at least one analgesic opioid dispensing or prescription, ranging from 4 per 1,000 in the United Kingdom to 191 per 1,000 in the U.S. publicly insured population. The greatest relative decrease in prevalence was observed in Hong Kong (prevalence ratio, 0.2; 95% CI, 0.1 to 0.2 between 2005 and 2020), and the greatest increase was in Iceland (prevalence ratio, 4.4; 95% CI, 3.7 to 5.2 between 2004 and 2017). Codeine and tramadol were among the three most prevalent opioids in most populations. In a sensitivity analysis defining opioid use as two or more opioid -dispensing or -prescribing events, the prevalence of opioid use across populations was 17 per 1,000. CONCLUSIONS: In this large multinational study, wide global variation in the prevalence of analgesic opioid use in pregnancy was observed, yet patterns of use by sociodemographic and pregnancy characteristics were relatively consistent. Analgesic opioid use remained stable or downward trending over time in most, but not all, countries.
3. Association of ventilation volumes, pressures and rates with the mechanical power of ventilation in patients without acute respiratory distress syndrome: exploring the impact of rate reduction.
Using individual patient data from three RCTs in non-ARDS patients (n=1,732), post hoc analyses showed mechanical power had a median of 12.3 J/min and was most strongly driven by pressures and respiratory rate. Rate reduction emerged as a practical lever to reduce mechanical power.
Impact: Clarifies actionable ventilator settings that dominate mechanical power, informing strategies to minimize ventilator-induced lung injury beyond tidal volume alone.
Clinical Implications: When targeting lower mechanical power in non-ARDS patients, prioritize careful respiratory rate and pressure adjustments (with permissive hypercapnia considerations) over tidal volume alone, balancing gas exchange and lung protection.
Key Findings
- Median mechanical power was 12.3 J/min (IQR 9.3–17.1; range 3.7–50.1) across 1,732 non-ARDS patients.
- Respiratory rate and pressure were the strongest determinants of mechanical power in regression and mediation analyses.
- Rate reduction identified as an attractive ventilator adjustment to lower mechanical power.
Methodological Strengths
- Individual patient data across three randomized trials, enabling robust multivariable and mediation analyses.
- Double stratification to test consistency across subgroups.
Limitations
- Post hoc observational analysis; causality cannot be inferred.
- Findings limited to non-ARDS populations and may not generalize to severe lung injury.
Future Directions: Prospective interventional trials testing respiratory rate-targeted strategies to reduce mechanical power and clinical outcomes, including VILI and mortality.
INTRODUCTION: High mechanical power is associated with mortality in patients who are critically ill and require invasive ventilation. It remains uncertain which components of mechanical power - volume, pressure or rate - increase mechanical power the most. METHODS: We conducted a post hoc analysis of a database containing individual patient data from three randomised clinical trials of ventilation in patients without acute respiratory distress syndrome. The primary endpoint was mechanical power. We used linear regression; double stratification to create subgroups of participants; and mediation analysis to assess the impact of changes in volumes, pressures and rates on mechanical power. RESULTS: A total of 1732 patients were included and analysed. The median (IQR [range]) mechanical power was 12.3 (9.3-17.1 [3.7-50.1]) J.min DISCUSSION: In this cohort of patients without acute respiratory distress syndrome, pressure and respiratory rate were the most important determinants of mechanical power. The respiratory rate may be the most attractive ventilator setting to adjust when targeting a lower mechanical power.