Daily Anesthesiology Research Analysis

BACKGROUND: Opioid-induced respiratory depression remains a critical public safety concern. Prior clinical findings demonstrated decreased hypercapnic ventilation after 5 days when paroxetine, a Selective Serotonin Reuptake Inhibitor (SSRI), was administered alone or with oxycodone. However, uncertainty remained whether chronic use of SSRIs could cause similar respiratory effects. This study investigated whether chronic use of paroxetine and another SSRI, escitalopram, lead to a similar decrease in ventilatory response to hypercapnia. METHOD: In this randomized, double-blind, 3-period crossover trial, healthy participants were administered one of the following: paroxetine 40 mg from days 1 to 6 and 60 mg from days 7 to 21, escitalopram 20 mg from days 1 to 6 and 30 mg from days 7 to 21, and placebo from days 1 to 21. Oxycodone 10 mg was co-administered on days 6, 12, and 21. Hyperoxic-hypercapnic ventilation was measured using Duffin's rebreathing. RESULTS: Of the 27 participants, 22 (81%) completed the trial. Paroxetine and escitalopram both significantly decreased hyperoxic-hypercapnic ventilation when co-administered with oxycodone compared to oxycodone alone on day 21 (paroxetine mean difference, -6.5 L/min [1-sided 97.5% CI, -∞ to -3.1] P<0.001, escitalopram mean difference, -5.5 L/min [1-sided 97.5% CI, -∞ to -2.1] P=0.001) and when administered alone compared to placebo on day 20 (paroxetine mean difference, -6.5 L/min [1-sided 97.5% CI, -∞ to -2.1] P=0.003, escitalopram mean difference, -6.9 L/min [1-sided 97.5% CI, -∞ to -2.5] P=0.002). CONCLUSIONS: Both paroxetine and escitalopram, alone and co-administered with oxycodone, decrease hypercapnic ventilation after 21 days suggesting that selective serotonin reuptake inhibitors may have a class effect on hypercapnic ventilation that persists with chronic use.

BACKGROUND: Neuraxial block failure in obese parturients is a significant clinical challenge, leading to inadequate pain relief and increased maternal risk. Novel techniques such as the Combined Spinal-Epidural (CSE) and Dural Puncture Epidural (DPE) have emerged as promising alternatives to standard epidural, but their comparative efficacy and safety have not been systematically evaluated in a comprehensive network. This systematic review and network meta-analysis aimed to determine the optimal neuraxial technique for preventing analgesia and anesthesia failure in obese parturients, with specific attention to morbidly obese subgroups and procedural efficiency. METHODS: Following Preferred Reporting Items for a Systematic Review and Meta-analysis (PRISMA) guidelines, we systematically searched PubMed, Embase, the Cochrane Library, and Web of Science for relevant studies published up to October 2025. We included randomized controlled trials (RCTs) that evaluated different neuraxial techniques in adult obese parturients (Body Mass Index ≥ 30 kg/m²). The methodological quality was assessed using the Cochrane Risk of Bias 2 tool. A frequentist random-effects network meta-analysis was used to calculate pooled Odds Ratios (ORs) and their 95% Confidence Intervals (CIs). The hierarchy of interventions was determined by P-scores. RESULTS: Eleven RCTs comprising a total of 1,178 patients were included in the final analysis. For the primary outcome of preventing block failure, CSE ranked highest (P-score 0.88), followed by DPE (P-score 0.74). Compared with the standard epidural technique, both CSE (Odds Ratio [OR] 0.41; 95% CI 0.19-0.93) and DPE (OR 0.50; 95% CI 0.31-0.82) significantly reduced the risk of failure. In the subgroup analysis of morbidly obese parturients (BMI ≥ 40 kg/m²), DPE and CSE remained the top-ranked interventions. Regarding safety, CSE was associated with a higher risk of hypotension compared to standard epidural, while DPE showed a comparable safety profile. Procedure times were generally similar across techniques, though heterogeneity existed. CONCLUSION: CSE and DPE appear to be the most effective neuraxial techniques for preventing block failure in obese parturients. While CSE ranks highest in efficacy, it carries an increased risk of hypotension. DPE offers a favorable balance of high efficacy and safety, particularly in morbidly obese populations. The choice of technique represents a clinical trade-off, where DPE may offer a more balanced efficacy and safety profile for labor analgesia. The optimal technique for cesarean delivery in this high-risk population remains uncertain due to a lack of direct comparative evidence, highlighting a critical area for future research. TRIAL REGISTRATION: The protocol for this systematic review was prospectively registered with the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD420251244336.

BACKGROUND: It remains unclear whether to continue or withdraw angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors (ACEI) before noncardiac surgery to reduce perioperative morbidity. This systematic review and meta-analysis aimed to analyze the consequences of continuing ARB or ACEi in the incidence of intraoperative hypotension and postoperative complications. METHODS: This systematic review and meta-analysis followed the PRISMA 2020 guidelines and was registered in the PROSPERO database. We conducted a comprehensive search in several bibliographic databases for studies comparing continuing versus withholding renin angiotensin aldosterone system antagonists before noncardiac surgery. Primary outcomes included the incidence of intraoperative hypotension, while secondary outcomes covered the intraoperative use of the vasoactive agent, the incidence of severe hypotension, intraoperative and postoperative hypertension, the incidence of acute kidney injury (AKI), 30-day postoperative all-cause mortality, and the incidence of major cardiocerebral events (MACCE). RESULTS: Five randomized controlled trials, three nonrandomized controlled trials, and four retrospective case-control studies were included that involved 50184 patients. Meta-analysis revealed that continuing ACEI or ARBs before surgery increased the incidence of intraoperative hypotension (OR = 1.96, 95%CI [1.30, 2.96] p=0.001). Heterogeneity was substantial across studies but was significantly reduced in subgroup analyses. Furthermore, the use of vasoactive agents and the incidence of severe hypotension were significantly higher in the continuing group. No significant differences in intraoperative hypertension and the incidence of AKI and MACCE at 30 days after the operation. CONCLUSIONS: Continued ACEI or ARBs before non-cardiac surgery increases the incidence of intraoperative hypotension, without reducing the incidence of both AKI and MACCE postoperatively. More research is necessary to explore the appropriate perioperative management of ACE-I and ARB.