Exploring the validity of the bispectral index, the Critical-Care Pain Observation Tool and vital signs for the detection of pain in sedated and mechanically ventilated critically ill adults: a pilot study.

This pilot study aimed to explore the validity of the bispectral (BIS) index, the Critical-Care Pain Observation Tool (CPOT) score, and vital signs (mean arterial pressure, heart rate) during rest and painful procedures in sedated and mechanically ventilated ICU adults. A convenience sample of nine patients with various diagnoses participated in this observational repeated measures study. Patients were observed during 2 minute periods at rest (baseline), and during procedures known to be painful: turning and endotracheal suctioning. Both the BIS index and the CPOT score were found to increase when patients were exposed to procedures compared with rest, and were found to be more sensitive to procedures compared with vital signs. Indeed, vital signs remained quite stable during procedures in this sample. Results from this study support the recommendation that behavioural indicators (i.e. in this case, the use of a behavioural pain scale called the CPOT) be used for the detection of pain in nonverbal ICU patients. However, in some situations (e.g. deep sedation, use of blocking agents), behavioural indicators may no longer be observable, and all that is left are physiologic signs. The BIS seems to be an interesting technique and further research is required in order to establish if it could be used to guide clinicians for the detection of pain in this vulnerable population.