A simultaneous comparison of three neonatal pain scales during common NICU procedures.

Objective: This study evaluated neonatal pain scales during procedures commonly performed in a neonatal intensive care unit.

Design: Evaluated were the Neonatal Infant Pain Scale (NIPS), the Comfort scale, and a new scale known as the Scale for Use in Newborns (SUN). Four procedures were scored: intubation, intravenous catheter insertion, endotracheal tube suctioning, and diaper changes. Scoring was done before, during, and after each procedure. Thirty-three patients were tested during 68 procedures with 1,428 scale scores.

Results: All scales demonstrated significant changes. In before-versus-during for each procedure, the increase in pain scale score was significant for the NIPS, Comfort scale, and SUN. All three scales also demonstrated a return to baseline (before-vs.-after) for the four procedures, except for the Comfort scale, which remained elevated (p < .05) following diaper change. The NIPS had a significantly larger coefficient of variation (CV, 188% +/- 99%), whereas the Comfort scale and SUN had small CVs (27% +/- 5% and 33% +/- 8%, respectively). In evaluating potential confounding influences, it was found that infants > 2.5 kg on sedative or analgesic medications appeared to have procedure-related accentuation and sustained elevation in scale scores, whereas swaddling seemed to provide little added benefit.

Conclusions: The pain scale scores identify changes in an infant's behavior/physiologic state. It is unclear whether these changes are totally "pain specific." In comparing the three scales, the SUN overall was a preferable tool because of its ease of use, scale symmetry, and scoring consistency.