Background: Infants during neonatal intensive care are invariably exposed to various procedural and environmental stimuli in which the pain-like responses may vary depending on the nature of the stimuli and the infants' condition.
Aim: To examine firstly the pain-like responses to frequent stimulants in the neonatal intensive care unit (NICU) using CRIES, FLACC and PIPP, and secondly the clinical feasibility and validity of using these pain measurements for high-risk infants.
Study design and subjects: In a correlational study of 110 premature infants receiving neonatal intensive care, the pain-like responses to 274 observations of 8 types of frequently applied stimulant, classified into three categories according to the degree of invasiveness, were observed using CRIES, FLACC and PIPP.
Results: There was a significant difference in response scores among the three categories for CRIES and PIPP. In post-hoc Scheffé test, category A had the highest response scores. The response scores from CRIES and FLACC were lower for the premature infants than for the full-term infants in both categories A and B, whereas the PIPP scores were higher for the premature infants than for the term infants in category C.
Conclusions: Full-term infants tended to express more distinct pain-like responses to invasive procedures or direct contacts than premature infants did. However, PIPP may be more sensitive to evaluate the negative effects of environmental auditory stimulants, particularly for premature infants receiving neonatal intensive care. Further study to refine these instruments may increase the clinical feasibility of pain measurements in high-risk infants.