Measurement of Acute Pain in Infants: A Review of Behavioral and Physiological Variables

Background: The use of non-validated pain measurement tools to assess infant pain represents a serious iatrogenic threat to the developing neonatal nervous system. One partial explanation for this practice may be the contradictory empirical data from studies that use newborn pain management tools constructed for infants of different developmental stages or exposed to different environmental stressors. Purpose: The purpose of this review is to evaluate the evidence regarding the physiologic and behavioral variables that accurately assess and measure acute pain response in infants. Methodology: A literature search was conducted using PUBMED and CINAHL and the search terms infant, neonate/neonatal, newborn, pain, assessment, and measurement to identify peer-reviewed studies that examined the validity and reliability of behavioral and physiological variables used for investigation of infant pain. Ten articles were identified for critical review. Principal findings: Strong evidence supports the use of the behavioral variables of facial expressions and body movements and the physiologic variables of heart rate and oxygen saturation to assess acute pain in infants. Conclusion: It is incumbent upon researchers and clinical nurses to ensure the validity, reliability, and feasibility of pain measures, so that the outcomes of their investigations and interventions will be developmentally appropriate and effective pain management therapies.