Purpose: The purpose of this study was to describe behavioral and physiologic indicators to a nociceptive procedure in conscious and unconscious mechanically ventilated adults and to examine their association with the patients' self-reports of pain.
Materials and methods: A total of 257 intensive care unit patients (144 conscious and 113 unconscious) from 4 clinical settings in Canada participated. Patients were observed at rest, during a nociceptive procedure, and 20 minutes postprocedure. Behavioral indicators were measured with the Critical Care Pain Observation Tool (CPOT), and physiologic indicators were documented from the available monitoring.
Results: Conscious patients showed more intense behaviors and a more elevated mean arterial pressure compared with unconscious patients at all measurements. Conscious patients who self-reported being in pain during the procedure showed more intense behaviors compared with patients without pain. Only the CPOT score could predict the presence or the absence of pain on the basis of the patient's self-report during the procedure.
Conclusions: The use of behaviors is strongly recommended for pain assessment in unconscious patients, and results from this study support this clinical guideline. Vital signs should be used with caution for the detection of pain as they can be influenced by other factors besides pain.