Related Experiment Video
Updated: Jan 20, 2026

Cutoff Value of Phase Angle by Bioelectrical Impedance Analysis at Admission as a Prognostic Factor in Patients with Acute Heart Failure
Published on: June 10, 2025
Parameters of Bioelectrical Impedance Are Good Predictors of Nutrition Risk, Length of Stay, and Mortality in
Elisa Loch Razzera1, Aline Marcadenti2,3,4, Susane Worlfarth Rovedder1
1Porto Alegre Federal University of Health Sciences, Porto Alegre, Brazil.
Background:
Assessment of nutrition risk in the intensive care unit (ICU) is limited by characteristics of critically ill patients, and new methods have been investigated for their applicability and predictive validity. The aim of the present study was to evaluate the validity of bioelectrical impedance analysis (BIA) parameters as predictors of nutrition risk and clinical outcomes in critically ill patients.
Methods:
This was a prospective cohort study of patients admitted to an ICU. The modified Nutrition Risk in the Critically Ill score was used for assessment of nutrition risk, and BIA was performed in the first 72 hours of admission. Phase angle (PA) measurements were obtained, and bioelectrical impedance vector analysis (BIVA) was used to classify patients by hydration status (BIVA >70%). Patients were followed until hospital discharge and evaluated for hospital mortality, ICU length of stay, length of hospitalization, and duration of mechanical ventilation.
Results:
Eighty-nine patients were included (62.5 ± 14.1 years, 50.6% female). A PA <5.5o showed an accuracy of 79% (95% CI 0.59-0.83) in identifying patients at high nutrition risk and was associated with nearly 2 times greater risk for an ICU length of stay longer than 5 days (relative risk = 2.18 [95% CI 1.39-3.40]). Hyperhydration was a significant predictor of mortality (hazard ratio = 2.24 [95% CI 1.07-4.68]). Higher resistance and reactance values, adjusted for height, were found in survivors compared with nonsurvivors.
Conclusion:
The predictive validity of BIA was satisfactory for the assessment of nutrition risk, ICU length of stay, and mortality in critically ill patients.
Related Concept Videos
The Roles of Bacteria and Fungi in Plant Nutrition
Parentral Nutrition: Centeral and Peripheral Parental Nutrition
PN can be administered through two primary routes:
1. Central Parenteral Nutrition (CPN):
CPN involves delivering a high concentration of nutrients through a large vein. This is typically achieved using a Peripherally Inserted Central Catheter (PICC) or,...
Microbial Nutrition
Critical Region, Critical Values and Significance Level
In hypothesis testing, a sample statistic is converted to a test statistic using z, t, or chi-square distribution. A critical region is an area under the curve in probability distributions demarcated by the critical value. When the test statistic falls in this region, it suggests that the null hypothesis must be rejected. As this region contains all those values of the...
Key Elements for Plant Nutrition
Critical Values

