The Critical-Care Pain Observation Tool (CPOT) and the Behavioral Pain Scale (BPS) may not be optimal tools to assess pain levels in agitated or sedated patients in intensive care units (ICU) but may be useful in a regular clinical setting, according to an observational prospective cohort study published in the Journal of Cardiothoracic and Vascular Anesthesia.
The CPOT is used for intubated and non-intubated critically ill patients who are unable to report level of pain (range 0-8 points).
The BPS is a validated tool to assess pain in unconscious ventilated patients and is the sum of scores evaluating upper limb movements, facial expression, and ventilation compliance, ranging from 3 points (no pain) to 12 points (maximal pain).
In the current study, 2 nurses evaluated independently CPOT and BPS scores in 72 patients admitted to the ICU in 4 situations: at rest, before a non-painful procedure (eg, oral care), during a second period of rest before a painful procedure, and during a painful procedure (eg, repositioning the patient). The first evaluations occurred at an average of 223 minutes after admission.
BPS scores increased between the first rest period (3 points) and the non-painful procedure (3.5 points; P =.001) for one nurse. This increase was the result of higher scores in facial expression and upper limb movement. The other nurse did not report an increase in BPS score, and CPOT scores remained unchanged between those 2 periods. Both BPS and CPOT scores increased by 2 points between rest before the painful procedure and the painful procedure.
The overall intraclass correlation coefficient used to assess interrater reliability was 0.74 for CPOT and BPS, indicating a fair-to-good agreement. During turning, the Cronbach coefficient α was 0.62 and 0.59 for BPS and 0.65 and 0.58 for COPT for nurses 1 and 2, respectively, indicating poor internal consistency for both tools.
Considering the 2 nurses in this study had prior knowledge of the pain associated with each procedure, they may have reported greater behavior changes during turning, thus affecting scores. In addition, there may have been possible selection bias in this study because of the small number of patients included in the final analysis.
“The discriminant validation of both [CPOT and BPS] scores seemed less satisfactory in sedated or agitated patients [than in a daily clinical setting],” concluded the investigators.
Rijkenberg S, Stilma W, Bosman RJ, van der Meer NJ, van der Voort PHJ. Pain measurement in mechanically ventilated patients after cardiac surgery: comparison of the Behavioral Pain Scale (BPS) and the Critical-Care Pain Observation Tool (CPOT). J Cardiothorac Vasc Anesth. 2017;31(4):1227-1234.