Association between early ondansetron administration and in-hospital mortality in critically ill patients: analysis of the MIMIC-IV database

While ondansetron (OND) is widespread availability, the contribution of OND to improve patient outcomes among intensive care unit (ICU) patients has not been examined. This study aimed to illustrate the association between early OND use and in-hospital mortality in critically ill patients and investigate whether this association differed according to OND dose.The MIMIC-IV database was employed to identify patients who had and had not received OND. Statistical approaches included multivariate logistic regression, propensity score matching (PSM), and propensity score-based inverse probability of treatment weighting (IPTW) models to ensure the robustness of our findings.In total, 51,342 ICU patients were included. A significant benefit in terms of in-hospital mortality was observed in the OND patients compared to the non-OND group in the early stage [odds ratio (OR) = 0.75, 95% CI 0.63-0.89, p < 0.001]. In the circulatory system group, the early OND administration was associated with improved in-hospital mortality in ICU patients (OR 0.48, 95% CI 0.34-0.66; P < 0.001). The risk of in-hospital mortality was also lower in early OND users than in non-OND users both in the medical admission group and the surgical ICU admission group, and ORs were 0.57 (95% CI 0.42-0.76; P < 0.001) and 0.79 (95% CI 0.62-0.91; P < 0.001), respectively. A positive role of daily low- and moderate-dose OND treatment in early-stage was showed on the in-hospital mortality in PSM cohort, and the ORs were 0.75 (95% CI 0.62-0.90; P < 0.001) and 0.63 (95% CI 0.43-0.91; P < 0.001), respectively. The relationship between the daily low- and moderate-dose of OND and in-hospital mortality was also significant in ICU patients with cardiovascular diseases, and ORs were 0.51(95% CI 0.36-0.73; P < 0.001), and 0.26(95% CI 0.11-0.65; P < 0.001), respectively. Daily low-to-moderate dose of OND was also associated with in-hospital mortality in ICU entire cohort.Early OND use is closely associated with lower in-hospital mortality in ICU patients. Daily low-to-moderate dose of OND application is protective against in-hospital mortality. This association is more evident in the circulatory system group.