Objectives: To examine the accuracy of inferences about critical care patients' pain based on physiological and behavioral indicators and to assess the relationship between registered nurse and patient pain scores and doses of opioids administered. Design: Descriptive, comparative analysis. Setting: Three intensive care units and two postanesthesia care units in two hospitals. Subjects: Fourteen critical care nurses who conducted 114 pain assessments on 31 surgical patients. Interventions: Nurses used a pain assessment and intervention notation algorithm that contained lists of behavioral and physiological indicators of pain to make inferences about a patient's pain intensity. Fourteen registered nurses completed up to five pain assessments on each patient over a 4-hr period. Following both the physiological and behavioral ratings, nurses rated the patients' pain intensity, using a 0 to 10 numeric rating scale, and they asked patients to provide a self-report of pain intensity, using a similar numeric rating scale. Nurses then administered an intravenous dose of an opioid from a sliding scale prescription. Measurements and Main Results: Moderate-to-strong correlations were found between the number of behavioral indicators at times 1 through 5 and between the number of physiological indicators and nurses' ratings of the patients' pain intensity at times 1 through 4 (p < .05). Although nurses' pain ratings were consistently lower than patients' pain ratings across the five time points, these differences were not significant. The amount of opioid analgesic administered by the nurse correlated more frequently with nurses' pain ratings than with patients' self-reports of pain intensity. Conclusions: The use of a detailed, standardized pain assessment and intervention notation algorithm that incorporates behavioral and physiological indicators-may assist healthcare professionals in making relatively accurate assessments of a patient's pain intensity. Further research is needed to determine the specific decision-making processes and criteria that healthcare professionals use to choose doses of analgesics to administer to critically ill patients.
