Low phase angle in critically ill older patients is associated with late mortality: A prospective study

Objectives: The aim of this study was to ascertain the accuracy of phase angle (PhA) as a predictor of mortality during intensive care unit (ICU) stay (MICU) and at 28 (M28) and 60 d (M60) after ICU admission among patients aged >60 y.Methods: Patients aged >60 y who were under mechanical ventilation (MV) >48 h were included once they were hemodynamically stable. PhA was measured by single-frequency bioelectrical impedance analysis up to 48 h after admission. ICU prognostic scores, functional scale, and nutritional assessments were performed in the first 24 h. Patients were followed for 60 d after ICU admission.Results: We enrolled 102 patients into the present study. PhA was significantly higher (P < 0.001) in survivors at MICU, M28, and M60. Areas under the receiving operator characteristic curves for MICU, M28, and M60 were 0.77 (95% confidence interval [CI], 0.67-0.86), 0.71 (95% CI, 0.60-0.82), and 0.71 (95% CI, 0.60-0.81), respec-tively. The PhA cutoff to predict mortality was 3.29 degrees for males at MICU, M28, and M60 and lower for females at M28 (2.63 degrees) and M60 (3.01 degrees). PhA better discriminated M60 than conventional prognostic scores. Logistic regression showed that even after controlling for other factors, PhA was a protective factor against late mor-tality. Survival analysis at 60 d revealed that low PhA was associated with lower median survival (18 versus 58 d; log-rank P < 0.001).Conclusions: Low PhA values are associated with higher late mortality and a short survival time at 60 d in crit-ically ill older adults. Low PhA values can be considered a useful ICU prognostic score in similar populations.(c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Phase angle (PhA) is associated with mortality in critically ill older adults during intensive care unit stay and at 28 and 60 days after ICU admission. Lower PhA values are associated with higher late mortality and shorter survival time.