Comparison of Two Pain Assessment Tools, "Facial Expression" and "Critical Care Pain Observation Tool" in Intubated Patients After Cardiac Surgery.

BACKGROUND: Critical-care patients are at higher risk of untreated pain, because they are often unable to communicate owing to altered mental status, tracheal intubation and sedation.

OBJECTIVES: This study compared two pain assessment tools on tracheal intubated critically ill patients in a cardiac post-anesthesia care unit, who were unable to communicate verbally. The studied tools were "critical-care pain observation tool (CPOT)" and "facial expression (FE)".

PATIENTS AND METHODS: This was a prospective study based on diagnostic test evaluation. A sample of 91 intubated patients was selected from cardiac post-anesthesia care unit. Collected data were demographic characteristics, vital signs, FE and CPOT tools' scale. Pain was assessed with CPOT and FE scores five times. The first assessment was performed in at least 3 hours after admission of patients to ICU. Then, the pain intensity was reassessed every 30 minutes. In addition, blood pressure, heart rate, respiratory rate and oxygen saturation were measured simultaneously.

RESULTS: At the first period, the frequency of "severe" pain intensity using the CPOT was 58.2% and with the FE tool was 67% (P = 0.001). Both tools demonstrated reduction in severity of pain on second and third assessment times. Significantly increasing level of pain and blood pressure due to nursing painful procedures (endo-tracheal suctioning, changing patient's position, etc.), were obtained by CPOT in fourth assessment. FE was not able to detect such important findings (κ = 0.249). In the fifth step, pain intensity was reduced. The most agreement between the two tools was observed when the reported pain was "severe" (κ = 0.787, P < 0.001) and "mild" (κ = 0.851, P < 0.001).

CONCLUSIONS: The sensitivity of CPOT was higher for detection and evaluation of pain in intubated postoperative patients compared with "Facial Expression". Best agreement between these tools was observed in two extremes of pain intensity.