Development and preliminary validation of the Neonatal Infant Acute Pain Assessment Scale (NIAPAS).

Background: Several pain scales are available for neonates, but, unfortunately they are only rarely used in clinical practice. To help with the current situation of unrecognized and under-treated pain in neonatal intensive care units (NICUs), we developed an assessment tool in close collaboration with clinical staff.

Objectives: To develop a multidimensional scale, NIAPAS (the Neonatal Infant Acute Pain Assessment Scale), that is sensitive to the needs of infants in neonatal intensive care units, and to test the validity, reliability, feasibility and clinical utility of the scale for this population.

Design: Instrument development and psychometric analysis.

Methods: Pain assessments (n=180) were made of 34 neonates born between 23 and 42 weeks gestational age who were undergoing 60 painful procedures (heel lance 77%, tracheal suctioning 23%) in the NICU. Using bedside video recordings, each neonate was observed through three phases of the procedure: 1 min before the procedure, during the procedure (lasting from 0.6 to 11.2 min, mean 2.6), and 1 min after the procedure. In addition, an expert panel (n=5) and nurses (n=26) participated in the validation of the scale.

Results: A pool of 8 pain indicators (5 behavioral and 3 physiological indicators), including the gestational age of neonates as a contextual factor, was identified based on the nurses' expertise in neonatal intensive care. Scores on the NIAPAS changed significantly across the phases (p<0.001), indicating a good construct validity of the scale. Correlations between the NIAPAS and NIPS (the Neonatal Infant Pain Score) were high (0.751-0.873). The study also demonstrated high coefficients for inter-rater (r=0.991-0.997) and intra-rater reliability (r=0.992-1.00), with an internal consistency of 0.723. The content validity was very good (Mean I-CVI 1.00), as evaluated by the expert group. The nurses agreed that the scale was easy to administer and that it helped decision-making in the pain management of infants.

Conclusions: The NIAPAS was shown to be a valid and reliable scale for assessing acute pain in preterm and full-term infants in the NICU. It allows nurses to evaluate infants' acute pain especially during painful procedures and help to provide pain relief for the infants.