Observational pain scales in critically ill adults.

Pain is a common and distressing symptom in critically ill patients. Uncontrolled pain places patients at risk for numerous adverse psychological and physiological consequences, some of which may be life-threatening. A systematic assessment of pain is difficult in intensive care units because of the high percentage of patients who are noncommunicative and unable to self-report pain. Several tools have been developed to identify objective measures of pain, but the best tool has yet to be identified. A comprehensive search on the reliability and validity of observational pain scales indicated that although the Critical-Care Pain Observation Tool was superior to other tools in reliably detecting pain, pain assessment in individuals incapable of spontaneous neuromuscular movements or in patients with concurrent conditions, such as chronic pain or delirium, remains an enigma.