Enteral branched-chain amino acid delivery and weaning outcomes in critically ill patients with hypoalbuminemia: a cohort study.

OBJECTIVES

Optimizing protein intake is crucial in critical care, but the specific role of branched-chain amino acids (BCAAs) from standard enteral nutrition (EN) in preserving respiratory muscle function is unclear. The aim of this study was to determine whether estimated enteral BCAA delivery is independently associated with weaning outcomes in mechanically ventilated, hypoalbuminemic patients.

METHODS

This single-center retrospective cohort study included 198 adult ICU patients with hypoalbuminemia (serum albumin <30 g/L) requiring mechanical ventilation for >48 h. Daily BCAA intake (g/kg/d) from standard EN over the first 7 ICU days was calculated from formula amino acid profiles. The primary outcome was weaning failure, defined as failed spontaneous breathing trial, reintubation within 48 h, or death within 48 h of ventilation withdrawal. Multivariable logistic regression and restricted cubic spline analyses were performed, adjusting for total protein and energy intake, disease severity, and other confounders.

RESULTS

Higher mean daily BCAA intake was independently associated with lower weaning failure (adjusted odds ratio per 0.1 g/kg/day increase: 0.62; 95% confidence interval: 0.41-0.93). Compared to the lowest intake quartile (<0.18 g/kg/d), the highest quartile (≥0.31 g/kg/d) had significantly reduced weaning failure (16.3% vs. 42.9%). Restricted cubic spline analysis revealed a non-linear, l-shaped relationship, with the benefit plateauing above approximately 0.25 g/kg/d.

CONCLUSION

Higher estimated enteral BCAA delivery is independently associated with successful weaning from mechanical ventilation in hypoalbuminemic critically ill patients. A potential threshold of 0.25 g/kg/d for BCAA intake warrants prospective investigation as a modifiable component of individualized nutrition therapy.