Poincaré Plot Indices as a Marker for Acute Pain Response in Newborns

Abstract

Traditional views on neonatal pain neglected long neglected the neonates’ capability of feeling pain. Newborn infants experience at least one painful procedure during their frst days of life, but with a lower gestational age, invasive procedures become more frequent and invasive. The modulation of the autonomic nervous system (ANS) is signifcantly changed during painful procedures. The analysis of the heart rate variability is shown to be a reliable tool in analyzing the ANS. In this study, the dynamic of the system has been examined by applying the Poincare plot analysis, a primer of nonlinear methods used in the analysis of the ANS. The aim of this study is to assess the occurrence of changes in linear heart rate variability parameters, to determine the changes in the Poincare plot indices and to evaluate the correlation between their diferences in healthy newborns. The results have shown a signifcant increase in the heart rate, a reduction of the duration of RR intervals, and the square root of the mean squared diferences between successive RR intervals (RMSSD), as well as a decrease in the short-term variability (SD1) of the Poincare plot. Te results highlight the need for studying the application of nonlinear analyses of the HRV on the efects of pain on the ANS and its long-term efects on the infant.