Pain measurement techniques: spotlight on mechanically ventilated patients

BACKGROUND: Procedural pain is a frequent problem in intensive care units (ICUs). For that, pain assessment has been increasingly introduced to the ICU professional’s routine, and studies have been developed to show the relevance of measuring pain in critically ill patients. OBJECTIVE: This review aimed to describe pain measurement techniques for mechanically ventilated adult patients based on evidence and already published. METHOD: Systematic literature search was performed on PubMed and Google Scholar. Keywords “pain”, “pain measurement”, “intensive care units” and “respiration, artificial” were combined to the Boolean operator AND. No language or publication year was limited in this search. The purpose and method of all papers were analyzed and only studies which described pain assessment in mechanically ventilated patients were included in this review. RESULTS: Objective methods were found in the literature to assess pain in mechanically ventilated adults. Behavioral scales were the most used method for pain measurement in noncommunicative patients. Vital signs were used, but the reliability of this method was questioned. Pupillometry, bispectral index and skin conductance were found and described as pain assessment methods. CONCLUSION: This review showed that objective measures, as behavioral scales, are the gold standard tools to measure pain intensity in noncommunicative subjects. These data contribute to professionals’ knowledge about ICU pain measurement and emphasize its importance and consequences for adequate pain management.