PAIN EVALUATION IN THE INTENSIVE-CARE UNIT - OBSERVER-REPORTED FACES SCALE COMPARED WITH SELF-REPORTED VISUAL ANALOG SCALE

Background and Objectives. The visual analog scale (VAS) is a simple a nd sensitive mean of pain assessment. The faces scale is also a simple , self-reporting method for children. Facial signs of pain have not be en used to assess pain in postoperative adult patients in the intensiv e care unit (ICU). Methods. Fifty patients undergoing esoph ageal canc er surgery by a thoracoabdominal procedure were studied. Epidural opio ids, such as morphine or buprenorphine, combined with bupivacaine were administered during and after surgery. Pain measurement was performed by a physician in the ICU using the self-reported VAS 0.5, 1, 2, 4, a nd 6 hours after tracheal extubation and thereafter every 4 hours duri ng the stay in the ICU. A nurse who was unaware of the patients' VAS s cores assessed facial expression as a measure of pain intensity using a five-grade faces scale immediately before pain evaluation by VAS. Th e VAS was rescaled into five discrete units that would match the five faces scale scores. Weighted kappa statistics were used to establish a relative level of agreement between the five-grade VAS and faces scal e. Results. Good agreement was found between the five-grade VAS and th e faces scale 30 minutes and 1 hour after tracheal extubation (weighte d kappa values .67 and .62, respectively). The VAS and faces scales we re measured 7-13 times per patient during the stay in the ICU, and 518 observations were collected. Although moderate agreement was found be tween the ave-graded VAS and faces scale for all pairs of observation: (weighted kappa values .54), less agreement was found between them in patients with moderate pain. In addition, the calculated mean differe nces between the five-graded VAS and faces scale differed significantl y between patients. Conclusion. The faces scale may be useful for pain evaluation in the ICU.