A review of objective pain measures for use with critical care adult patients unable to self-report.

UNLABELLED: Critically ill patients experience significant levels of pain and discomfort from multiple intrinsic and extrinsic sources while in the intensive care unit (ICU). The use of objective pain measures in nonverbal patients is an essential alternative approach for pain assessment when self-reports are unavailable. This paper provides a critical review of the psychometric properties of 6 objective pain measures that were developed to assess pain in nonverbal adult patients in the ICU. The strengths and weaknesses of these objective measures are evaluated, as well as their applicability for use with this patient population. Although 2 of the 6 objective pain measures showed good evidence of validity and reliability, none has undergone vigorous validation or has been accepted as a standardized measure. Findings from the available studies of objective pain measures provide useful information to direct future research to develop and validate clinically useful pain measures for use with critically ill patients unable to self-report. PERSPECTIVE: This review provides clinicians with a summary of the psychometric properties of 6 objective pain measures and discusses their applicability for use to assess pain in critically ill adult patients unable to self-report.