Pain Measurement in Critically Ill Non-Verbal Patients With Brain Injury: A Systematic Review.

Pain management in critically ill patients with brain injury is a clinical and ethical concern in critical care settings that is complicated by altered consciousness and communication barriers. To identify, synthesise and categorise methods for effective pain assessment in critically ill, non-verbal patients with brain injury in critical care settings. A systematic review following PRISMA guidelines, registered in PROSPERO, included 13 articles that examined pain among those patients. Validated assessment tools, such as the Critical Care Pain Observation Tool and the Behavioural Pain Scale, remain the gold standard for pain assessment in patients with brain injury. The most universal behavioural indicators of pain in these patients are frowning, sudden eye opening and limb flexion. However, behavioural indicators are often blunted by the level of consciousness, sedation or severity of injury. Conversely, physiological parameters lack diagnostic specificity and might be confounded by autonomic nervous system instability or medications. Emerging advanced technologies offer an objective approach to the nociception process. Clinicians should be cautious while assessing pain in brain-injured patients; a low pain score may be a false negative caused by the inability to react rather than an actual absence of pain. It is recommended to adopt a multi-modal approach for pain assessment in critically ill patients with brain injury. The findings may inform pain assessment protocols in critically ill non-verbal patients with brain injury, suggesting that using an isolated approach is inadequate and inaccurate.