Phase Angle for Nutritional Risk Screening in Cardiac Critically Ill Patients

Introduction: The phase angle has been listed as a nutritional marker and its useful role in critically ill patients, but its role as a patient-to-patient tool has not yet been tested. This study sought to evaluate the phase angle as a proposal to determine nutritional risk in critically ill patients hospitalized in cardiac intensive care units. Methods: Transversal study, coupled to a prospective analysis variable (hospitalization outcome) and involving adult and elderly male and female patients in cardiac intensive care units. The nutritional risk was determined by using the NUTRICscore, the phase angle was obtained through bioelectrical impedance analysis and other data, through the clinical record. A significance level of p <0.05 was used for all statistical analysis. Results: 79 patients were included and resulted in homogeneous distribution among the sexes and an average age of 67.2 ± 13.7 years. Most of the sample had malnutrition according to the body mass index (BMI) (46.7%; CI: 36.0-57.8) and due to the adequacy of the arm circumference (40.8%; CI: 34.0-52.0). According to the NUTRIC score, 59.5% (CI: 48.5-69.3) had a high nutritional risk, and 68.4% (CI: 57.4-77.6) had a low phase angle (≤5.5 °). Correlation between the phase angle and age (p = 0.010) and BMI (p = 0.023) was verified. A good sensitivity (72%; CI: 55.6-81.9) and specificity (68%; CI: 42.5-77.5) of the low phase angle were obtained to detect nutritional risk by NUTRIC. Conclusions: The PhA had good results of sensitivity and specificity but should be used with caution to determine the nutritional risk in critically ill cardiac patients.