Association between serum lactate levels and refeeding syndrome in critical Ill patients.

Aim: To analyze the relationship between blood lactate levels and the development of refeeding syndrome (RFS) in critically ill patients. Methods: This prospective cohort study enrolled patients aged 18 years and older who were admitted to the intensive care unit (ICU) of the Hospital Clínica San Francisco for at least 48 hours between January and June 2019. RFS was defined as a 30% decrease in serum phosphorus within 48 hours after the initiation of nutritional support. Serum lactate, SOFA, APACHE II, nutritional risk, and nutritional status were measured upon ICU admission. Statistical analyses were conducted using Student's t-test, Mann-Whitney U test, and Wilcoxon test. Results: A total of 141 patients were selected, with 53.8% (n = 83) being male, and 34.8% (n = 49) develped RFS. The primary diagnoses were sepsis and neurocritical conditions, with an overall mortality rate of 18.4%. Among patients with RFS, 85.7% (n = 41) were identified as having a nutritional risk at admission, and 53.1% (n = 26) had moderate malnutrition. Patients with RFS experienced longer ICU stays (12 vs. 7 days, p = 0.006) and longer hospital stays (22 vs. 15 days, p = 0.007) compared to those without RFS. Patients with RFS had significantly higher serum lactate levels compared to those without RFS (1.62 vs. 2.14 mmol/l; p=0.002). Conclusions: In the present study, serum lactate level is associated with the development of RFS in critically ill patients.