Temporal assessment of neonatal pain after airway aspiration

To temporally assess a painful stimulus in premature infants using 3 neonatal pain scales.

A total of 83 premature infants were observed during airway aspiration by 3 evaluators (E1, E2 and E3) using 3 pain assessment scales (Neonatal Facial Coding System - NFCS; Neonatal Infant Pain Scale - NIPS; and Premature Infant Pain Profile - PIPP) at 5 time points: T1 (before airway aspiration), T2 (during airway aspiration), T3 (1 minute after airway aspiration), T4 (3 minutes after airway aspiration), and T5 (5 minutes after airway aspiration). Light's Kappa (agreement among examiners and among scales at each time point) and the McNemar test (comparison among time points) were used considering p < 0.05.

There was a significant difference between the 3 examiners for T1 and T2 using the 3 scales. In T3, pain was observed in 22.9%/E1, 28.9%/E2, and 24.1%/E3 according to the NFCS; 22.9%/E1, 21.7%/E2, and 16.9%/E3 according to the NIPS; and 49.4%/E1, 53.9%/E2, and 47%/E3 according to the PIPP. There was a difference between T1 and T3 using the 3 scales, except for 2 examiners for the PIPP (E2: p = 0.15/E3: p = 0.17). Comparing T4 and T5 to T1, there was no difference in the 3 scales.

Premature infants required at least 3 minutes to return to their initial state of rest (no pain).