The neonatal intensive care unit (NICU) is synonymous with multiple invasive procedures that result in pain and stress in the neonate [1-3]. Inadequately managed pain from repeated painful events during a critical period of infant brain development can compromise neuronal and synaptic organization permanently [4,5] and predispose the infant to significant immediate neurophysiologic adverse events (eg, intraventricular hemorrhage) and long-term neurobehavioral and cognitive sequelae throughout the developmental spectrum of childhood [6-9]. Furthermore, both noxious and non-noxious stimuli during this highly vulnerable period may result in persistent or chronic pain [4]. Therefore, preventing or minimizing pain associated with the NICU experience and its immediate and long-term consequences is of paramount importance to the development and quality of life in these vulnerable infants and their families. In the past decade, impressive advances have been realized in the development of pain assessment in infants. In excess of three dozen measures have been developed for assessing pain in term and preterm neonates and older infants and have been evaluated in several recent reviews [10-12]. Although the number of measures with established reliability and validity is constantly increasing, the majority of these instruments have been developed and used primarily for research purposes. In addition, following the determination of beginning levels of content and face validity and inter-rater reliability, most instrument developers abandon this often-thought "tedious task" of establishing the more complex properties such as construct validity, feasibility, and clinical utility. Therefore, very few infant pain measures have established these properties, with the least attention being paid to clinical utility. Similar to the advances in pain assessment, great strides have been made in the evaluation of pharmacologic [13], behavioral, and environmental strategies [14] for managing acute procedural and postoperative pain in infants. Although many of these interventions have been reported to be statistically superior to a control/placebo or no-treatment group, the clinical significance or importance of the research results has not been delineated. Many of these strategies have been systematically reviewed in terms of their safety, efficacy, and effectiveness [15,16] and included in evidence-based clinical guidelines, standards, and statements from professional organizations [17] and expert consensus groups [18]. These guidelines and standards are meant to form the basis for improving clinical practice in regard to infant pain and, ultimately, infant outcomes. Despite these accomplishments in advancing knowledge on pain assessment and management in infants, the results of this research have not been effectively translated into practice [19,20]. Clinicians frequently do not possess adequate quantitative or qualitative information about the infant's pain to make informed decisions regarding the intervention that will have the most clinical benefit. The reasons for this inadequacy are multifaceted and include factors related to the individual implementing the intervention, the environment into which the intervention is being introduced, and the intervention itself [2 1]. Insufficient attention to (1) the establishment of psychometric properties (ie, reliability and validity), feasibility, and clinical utility for infant pain measures to accurately assess pain; (2) the use of these measures to determine the effectiveness of interventions; and (3) the determination of the clinical significance of research results from intervention studies also contribute to the research-practice gap. Furthermore, understanding the clinical importance of relieving pain in infants is highly relevant for attaining successful outcomes in vulnerable neonates and infants. In this article, two major issues of relevance to clinicians-clinical utility of measures and clinical significance of pain-relieving interventions-are explored in relation to infant pain assessment and management. The issue of clinical importance in reducing pain and stress in neonates is also addressed.
