Pain assessment in the critically ill adult: Recent evidence and new trends.

Pain assessment in the critically ill adult remains a daily clinical challenge. Position statements and practice guidelines exist to guide the ICU care team in the pain assessment process. The patient's self-report of pain remains the gold standard measure for pain and should be obtained as often as possible. When self-report is impossible to obtain, observational pain scales including the Behavioural Pain Scale (BPS) and the Critical-Care Pain Observation Tool (CPOT) have been recommended for clinical use in the critically ill adult. However, their adaptation and validation in brain-injured and burn ICU patients is required. Family caregivers may help in the identification of pain-related behaviours and should be more involved in the ICU pain assessment process. Fluctuations in vital signs should only be considered as cues for further assessment of pain with appropriate tools, and may better represent adverse events of severe pain. Other physiologic measures of pain should be explored in the ICU, and pupillometry appears as a promising technique to further study. Implementation of systematic pain assessment approaches using tools adapted to the patient's ability to communicate and condition has shown positive effects on ICU pain practices and patient outcomes, but randomised control trials are needed to confirm these conclusions.