Incidence and mortality of refeeding syndrome in critically ill patients: a systematic review and meta-analysis

To systematically review the literature and to synthesize evidence regarding the incidence and mortality of refeeding syndrome in critically ill patients. This study was registered on the PROSPERO database. We performed a systematic review on the Medline, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials databases. Randomized clinical trials (RCT) and observational studies including critically ill adult, pediatric, and neonatal patients that reported the incidence and/or mortality of refeeding syndrome were eligible. Two reviewers independently screened studies , extracted data, and assessed risk of bias using the Newcastle-Ottawa scale for cohort studies and the Cochrane Collaboration tool for RCT. The pooled effect estimates for binary and continuous variables are shown using proportions, odds ratio (OR), or mean differences (MD) with 95% confidence intervals (CI). Certainty of the evidence was assessed using the GRADE approach. Twenty-eight studies including 10,412 patients were analyzed. The reported incidence of refeeding syndrome ranged from 0% to 88%, with a pooled incidence of 23% (95% CI 15–33), showing substantial heterogeneity (I2 = 99%). In sensitivity analyses stratified by age, the pooled incidence was 29% (95% CI 19–41) in adults, 5% (95% CI 3–9) in pediatric patients, and 25% (95% CI 17–35) in neonates. No consistent association between refeeding syndrome and mortality was observed in the overall population (OR 1.51, 95% CI 0.79–2.88), nor in adult or pediatric subgroups. Evidence regarding neonatal mortality was limited to a single study. Refeeding syndrome was frequently observed among critically ill patients and showed substantial variability across age groups and study definitions. In this meta-analysis, refeeding syndrome was not statistically associated with mortality; however, the certainty of evidence was low and heterogeneity was high. These findings highlight the need for standardized definitions and higher-quality studies to better clarify the clinical implications of refeeding syndrome in critically ill populations.