The relationship between behavioral states and pain responses to various NICU procedures in premature infants

An explanatory observational study was conducted to assess the behavioral state before and during various procedures in the neonatal intensive care unit (NICU) and to investigate the relationship between the behavioral state measured by Anderson Behavioral State Scoring System (ABSS) and the degree of pain responses as measured using CRIES (Crying, Requires O(2) for oxygen saturation above 95, Increased vital signs, Expression, and Sleeplessness.) and PIPP (Premature Infants' Pain Profile). Ninety-one observations in 6 NICU procedures were made from 54 infants with a mean gestational age (GA) of 30(+4) weeks and a mean body weight (BW) of 1484.87 g. A positive relationship was identified between ABSS and CRIES, both before (r=0.244, p=0.020) and during (r=0.745, p=0.000) the procedures, and between CRIES and PIPP (r=0.447, p=0.000) during the procedures. However, no correlation was identified between PIPP and ABSS before (r=-0.055, p=0.651) and during (r=0.214, p=0.074) the procedures. This study concluded that relatively healthy, premature infants are in a state of quiet or active sleep and can adequately express pain-related responses to the NICU procedures that are appropriate with the nature of stimulation. However, it was observed that clinicians tend to pay little attention to the state of premature infants before performing the procedures, regardless of their invasive and stimulatory nature. Further research needs to be conducted on the pain responses in physiologic and behavioral expression of critically ill infants who possibly have alteration and developmental limitations in response.