Incidence, risk factors and outcomes of refeeding syndrome in critically ill patients receiving enteral nutrition: a prospective observational study.

OBJECTIVE: Refeeding syndrome (RFS) is a serious metabolic complication that may increase mortality in patients receiving enteral nutrition (EN). This study aims to investigate the incidence, risk factors of RFS within the ASPEN-defined 5-days window in critically ill patients receiving EN, and to evaluate its association with prolonged ICU length of stay and ICU mortality. METHODS: A single-center prospective observational study was conducted in the emergency intensive care unit. Electrolyte and biochemical analysis were collected at admission and on days 3 and 5 of EN. Data on ICU length of stay and ICU mortality were collected. Univariate and multivariate Firth's penalized logistic regression analyses were used to identify risk factors for RFS. RESULTS: A total of 294 patients were enrolled. The incidence of RFS was 62.9% (185/294) on day 3 and 71.4% (210/294) on day 5 of EN (P < 0.001). Overall ICU mortality was 12.9% (38/294). Moderate/severe RFS was associated with significantly higher ICU mortality compared with the combined mild/no-RFS group on day 3 (OR = 2.14, 95% CI: 1.06-4.28, P = 0.036) and day 5 (OR = 2.47, 95% CI: 1.22-4.99, P = 0.014). Multivariate analyses identified baseline serum magnesium, phosphate, and potassium as independent risk factors of RFS. CONCLUSION: Refeeding syndrome incidence in critically ill patients receiving EN remains high, with progressive elevation during the first 5 days. Patients who developed moderate/severe RFS on days 3 and 5 had significantly higher ICU mortality than those mild/no-RFS patients. Baseline serum phosphorus, potassium, and magnesium were risk factors of RFS.