Low phase angle is associated with 60-day mortality in critically ill patients with COVID-19

Malnutrition status, body composition indicators, and bioelectrical impedance analysis (BIA) parameters have been associated with increased risk of death in several pathologies. The aim of this study was to describe the associations between phase angle (PhA) indicators obtained by BIA with length of hospital stay, days on mechanical ventilation, and 60-day mortality in critically ill patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

This is a prospective cohort of mechanically ventilated patients with coronavirus disease 2019 (COVID-19). We assessed nutrition risk and body composition with BIA within 48 h from intensive care unit admission. Logistic and linear regression models were used to analyze the association between variables and clinical outcomes. Survival analysis by PhA value was performed using Kaplan-Meier curves.

Sixty-seven patients were included. PhA (odds ratio [OR], 0.36; P = .002), standardized PhA (SPA) (OR, 0.45; P = .001), and extracellular water/total body water ratio (OR, 3.25; P = .002) were significant predictors of 60-day mortality. PhA <3.85° in females and <5.25° in males showed good and fair discrimination, respectively, for mortality prediction. Using cutoff values, low PhA was associated with a significantly increased risk of 60-day mortality (hazard ratio, 3.08; 95% CI, 1.12-8.41; P = .02). No association was detected for SPA.

Low PhA values could be a predictor of 60-day mortality in critically ill patients with COVID-19. This biological marker could be incorporated as part of nutrition and mortality risk assessment in this population.