A Pilot Study on Pain Assessment Using the Japanese Version of the Critical-Care Pain Observation Tool.

BACKGROUND

Critically ill patients experience various types of pain that are difficult to assess because patients cannot communicate verbally due to artificial airways and sustained sedation. The Critical-Care Pain Observation Tool (CPOT) objectively evaluates patients' pain.

AIMS

This study aimed to re-assess the reliability and validity of the Japanese version (CPOT-J) and to reveal limitations of behaviors specific to mechanically ventilated patients.

DESIGN

Secondary analysis of observational pilot study and case report.

PARTICIPANTS

METHODS: We obtained consent preoperatively from 40 cardiovascular surgery patients. CPOT-J scores were evaluated immediately before, immediately after, and 20 minutes after painful stimulation. Inter-rater reliability was determined by the researcher and 18 ICU nurses (minimum one-year ICU experience). Validity was examined by comparing CPOT-J with vital sign values and patients' self-reports of pain. Two cases revealed the tool's characteristics: one score was consistent with patient reports while the other was not.

RESULTS

We evaluated pain in 34 patients (26 men, 8 women; mean age = 66.8 years). Weighted kappa scores ranged from 0.48 to 0.94. The tool only correlated with changes in systolic blood pressure and pulse pressure. Case studies indicated that the tool effectively evaluated mid-sternum-wound pain, but not back pain at rest.

CONCLUSIONS

The CPOT-J can assess pain in mechanically ventilated patients, but being immobile results in a score of 0 for body movement (e.g., being immobile while feeling back pain) and is a limitation of the scoring.