Sedation-Ventilation Dyssynchrony Early After Cardiac Surgery Is Associated With Reintubation and Postoperative Complications: A Retrospective Cohort Study With Mediation Analysis.

OBJECTIVES: To evaluate whether early intensive care unit (ICU) sedation-ventilation dyssynchrony (SVD) is associated with reintubation and postoperative complications after cardiac surgery-delirium, postoperative atrial fibrillation, acute kidney injury (AKI), renal replacement therapy, and 30-day mortality-and to explore what proportion of the SVD-AKI association is compatible with mediation by reintubation. DESIGN: Retrospective single-center cohort study with inverse probability of treatment weighting (IPTW), Fine-Gray competing-risk regression, multiple imputation, and exploratory counterfactual mediation analysis. SETTING: Cardiac surgical ICU of a tertiary referral hospital, January 2021 to December 2025. PARTICIPANTS: A total of 3,124 consecutive adult patients undergoing cardiac surgery and admitted intubated to the ICU. INTERVENTIONS: None (observational). The exposure-SVD-was classified within the first 12 hours of ICU stay using the standardized Richmond Agitation-Sedation Scale, Confusion Assessment Method for the ICU, arterial blood gas, and ventilator variables and stratified into 3 mutually exclusive phenotypes: SVD-Deep only, SVD-Light only, and both. MEASUREMENTS AND MAIN RESULTS: The primary outcome was reintubation within 72 hours of planned extubation. SVD occurred in 780 of 3,124 (25.0%); reintubation occurred in 157 of 3,124 (5.0%). In IPTW-adjusted analyses, SVD was associated with reintubation (adjusted odds ratio [aOR], 3.4; 95% confidence interval [CI], 2.5-4.6), noninvasive ventilation/high-flow nasal cannula rescue (aOR, 2.2), delirium (aOR, 2.6), postoperative atrial fibrillation (aOR, 2.1), AKI (aOR, 2.9), renal replacement therapy (aOR, 3.2), and 30-day mortality (aOR, 2.4); the Fine-Gray subdistribution hazard ratio for reintubation was 3.1 (2.3-4.3). In an exploratory mediation analysis, an estimated 41% (95% CI, 28%-54%) of the SVD-AKI association was compatible with mediation through reintubation; the E-value for the primary association was 6.1. CONCLUSIONS: Early ICU SVD was independently associated with a 3-fold higher adjusted risk of reintubation and with consistent increases across organ-specific complications after cardiac surgery. SVD is identifiable with routinely available bedside variables and warrants prospective multicenter validation before clinical implementation.