Determinants of premature infant pain responses to heel sticks.

The exposure of premature infants to stressors, such as pain intended to ensure their survival, may instead alter their brain development and contribute to several learning and behavioral difficulties observed in later childhood. The objective of this descriptive, cross-sectional study was to compare the pain responses of 72 preterm infants to a heel stick procedure taking into consideration a variety of factors, including the use of opioids and sedatives. The pain scores assessed on the Preterm Infant Pain Profile (PIPP) scale were highest for the lowest gestational age (GA) group. Multiple linear regression analysis with the four predictor variables noted to be correlated with the PIPP scores (GA, type of needle, severity of illness, and behavioral state) indicated a significant overall relationship (F [5/66] = 5.62, p < 0.01) and accounted for 44% of the variance. All but severity of illness did not add significantly to the variance. Gender, postnatal age, amount, opioids, and sedatives used were not correlated to the PIPP scores. It was concluded that sick premature infants and those who have been exposed to a variety of painful procedures may not manifest behavioral or physiological signs of pain, but may be the most to benefit from precise pain assessment and prudent management.