N-PASS: Neonatal Pain, Agitation and Sedation Scale Reliability and Validity


Patricia A. Hummel, Mary L. Puchalski, Steven D. Creech, Marc G. Weiss.
Pediatrics/Neonatology, Loyola University Medical Center, Maywood, IL Perinatal Center, Oncology Institute

Vol. 2, N. 6, Novembre 2004



BACKGROUND: Pain and sedation assessment are an important aspect of medical care of the hospitalized patient of all ages. Inadequate pain assessment contributes to sub-optimal pain management leading to morbidity and mortality. A clinically useable, reliable, and valid pain and sedation tool is needed to improve patient care and clinical outcomes. The currently available Premature Infant Pain Profile (PIPP) was created for procedural pain. The N-PASS: Neonatal Pain, Agitation and Sedation Scale was developed in response to the need for a clinically useable, consistent, age appropriate assessment and documentation methodology for ongoing infant pain and also sedation in the neonatal intensive care unit (NICU) of Ronald McDonald Children's Hospital of Loyola University Medical Center.

OBJECTIVE: To establish the inter-rater and internal consistency as measures of reliability of the N-PASS instrument as well as the convergent and concurrent validity.

DESIGN/METHODS: NICU nurses were trained in the N-PASS and the PIPP. Invants 0-100 days of age were selected for assessment if receiving mechanical ventilation or were in the immediate post-operative period. Assessments were made by two nurses, one using both tools and one using the N-PASS alone, immediately before and one hour after pharmacologic intervention. Subjects were studied on up to 5 different occasions. Results were analyzed using Spearman's rank correlation coefficient, Intra-class Correlation Coefficient, ICC (1,2), Cronbach alpha, and Wilcoxon rank-sum test; p<0.05 was considered significant.

RESULTS: Assessments were made on 72 subjects. Inter-rater reliability was 0.95 for pain and 0.90 for sedation N = 32, p<0.0001 for both). Internal consistency for pain varied from 0.31 at low pain scores, to 0.82 at high pain scores. Consistency was more constant for sedation, 0.87-0.91. Concurrent validity of pain assessment between N-PASS and PIPP was 0.83 at high pain scores and 0.61 at low scores. There was good discriminate validity, pre-intervention pain score 4.26 ±3.6, post-intervention pain score 1.81 ±1.5 (p<0.0001). Discriminate validity for sedation was significant with scores from -0.85 ±1.7 pre-sedation to -2.78 ±2.8 post-sedation (p<0.0001).

CONCLUSIONS: The N-PASS is a reliable assessment tool for neonatal pain and sedation. It is a valid assessment tool for ongoing pain and sedation for the term and preterm infant. Internal consistency was high except at lower pain scores. Stratification of the data by gestational age may clarify the low internal consistency at low pain scores.


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