CONTRIBUTION OF RECURRENCE GRAPHS IN THE PROGNOSTIC ASSESSMENT OF INTENSIVE CARE UNIT PATIENTS

Abstract

This study evaluated heart rate variability (HRV) in patients admitted to the intensive care unit with the aid of recurrence charts. This is a quantitative, qualitative, prospective and longitudinal study and the selected patients were divided into survivors group and death group. Time series of heart pulses were used with the Polar Advanced RS800CX frequency meter for 30 minutes. The analysis of the recurrence data used the following selected parameters: dimension = 2, delay = 2, radius = 70, line = 2 and as color scheme the Volcano. The classic variables of the recurrence plots were selected: ApEn, SamPEn, Alpha 1, % Recurrence, Det%, Laminarity, TT and LDmax. The continuous quantitative variables with Gaussian distribution were treated with the aid of Fischer's exact test and unpaired Student t test, and p values < 0.05 were considered significant. The time series data of heart pulses were filtered and later analyzed with the software Kubios HRV Analysis.and the software Visual Recurrence Analysis. A total of 92 patients were considered, with the group of deaths consisting of 32 patients and the group of survivors by 60. indicating greater linearity (greater impairment of homeostasis). The analysis of HRV with the aid of recurrence charts allowed the differentiation of health states, and may act as a marker of severity and death.