Evaluation of the usefulness of two established pain assessment tools in a burn population

Evaluation of burn pain and its successful treatment has proven challenging for all staff who care for burn patients. As successful pain relief is important for full physical and psychological recovery, accurate assessment of burn pain is essential. The authors sought to prospectively evaluate two previously validated pain scales, the Critical Care Pain Observation Tool (CCPOT) and the Adult Nonverbal Scale (ANVS), in our burn population and compare them with patients' reports of pain. Both scales include nonverbal behaviors that are numerically scored and can be used in communicative as well as noncommunicative patients. Thirty-eight patients underwent 225 paired pain assessments. Assessments were compared with patients' self-reports of pain using the numeric rating scale (NRS) and the visual analog scale (VAS). Performance of the scales was evaluated by psychometric analysis. Logistic regression was used to compare pain scores with patient demographics, burn demographics, and administered analgesia. Both CCPOT and ANVS were internally consistent and able to discriminate pain intensity. However, these scales had poor interrater reliability. Furthermore, they correlated poorly with patients' self-reports of pain per the NRS and VAS pain scale scores. By logistic regression, all the pain scales showed a decrease in patient pain corresponding to the length of time after the burn. Otherwise, pain was not related to any patient demographics or evaluator experience. The size of burn was the only burn-related variable significantly associated with the pain scores, and this was only for the scores obtained with the CCPOT scale. In addition, only CCPOT and ANVS scales correlated with administered analgesia during hospitalization. The authors conclude that CCPOT and ANVS do not accurately assess pain in burn patients. However, it seems that the staff may administer analgesia based on several nonverbal clues encompassed in these scales. Future studies should address nonverbal signs of pain in burn patients. These signs could then be used in pain scales to target burn patient pain more effectively.