Safety and adverse events associated with dexmedetomidine for sedation in adult ICU patients: a systematic review and meta-analysis.

Background: Dexmedetomidine (DEX) is increasingly used for sedation in critically ill adults due to its favorable pharmacokinetic profile and potential benefits over traditional sedatives. However, concerns persist regarding its cardiovascular safety. This meta-analysis comprehensively evaluates the incidence and nature of adverse events associated with DEX sedation in adult intensive care unit (ICU) patients. Methods: We conducted a systematic review and meta-analysis according to PRISMA 2020 guidelines. A meta-analysis search of PubMed, Embase, and Cochrane Library was conducted from database inception to June 18, 2025 for randomized controlled trials (RCTs), prospective/retrospective cohort studies, or descriptive studies with a comparator group, reporting safety outcomes in adults receiving DEX for ICU sedation. Primary outcomes were hemodynamic adverse events including hypotension, bradycardia, tachycardia. Data were pooled using fixed-effects models, calculating odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was assessed using I2 statistics. Risk of bias was evaluated using Cochrane RoB 2.0 for RCTs and Newcastle-Ottawa Scale (NOS) for observational studies. GRADE assessed evidence certainty. Results: Ten studies (7 randomized controlled trials, 3 cohorts; total n = 1,456 patients) were included. Meta-analysis demonstrated a significantly increased risk of bradycardia with dexmedetomidine versus controls (9 studies, n = 1,590; pooled OR = 2.38, 95% CI [1.77, 3.21], p < 0.00001; I2 = 0%; high certainty evidence). No significant increase in overall hypotension risk was observed (9 studies, n = 1,422; OR = 1.15, 95% CI [0.91, 1.47], p = 0.25; I2 = 44%; moderate certainty), though subgroup analyses indicated elevated risks in vulnerable populations. A modest but significant increase in tachycardia risk was found (4 studies, n = 1,084; OR = 1.38, 95% CI [1.03, 1.83], p = 0.03), with substantial heterogeneity (I2 = 93%; low certainty) suggesting context-dependent effects. Risk of bias was generally low for RCTs, while observational studies demonstrated good quality but limited confounding adjustment. Conclusion: Dexmedetomidine use for ICU sedation is consistently associated with a significantly increased risk of bradycardia. While the overall risk of hypotension was not significantly elevated, specific patient populations may be vulnerable. Tachycardia risk appears modest but highly variable. These findings underscore the necessity for careful patient selection, continuous hemodynamic monitoring particularly heart rate, and cautious titration when using DEX in critically ill adults. Future research should focus on high-risk subgroups and standardize adverse event definitions.