Discriminative ability of the Behavioural Indicators of Pain Scale-Brain Injury (Escala de Conductas Indicadoras de Dolor-Daño Cerebral) according to level of sedation in critically ill patients with acquired brain injury and disorders of consciousness: A multicentre observational study

BACKGROUND: Appropriate assessment of pain is essential to ensure effective treatment. OBJECTIVES: The objective of this study was to determine the discriminative ability of the Behavioural Indicators of Pain Scale-Brain Injury (Escala de Conductas Indicadoras de Dolor-Daño Cerebral [ESCID-DC]) under different sedation levels (deep vs. light-to-moderate) and procedures in critically ill patients with acquired brain injury and disorders of consciousness. METHODS: A multicentre, observational study was conducted involving critically ill patients with acquired brain injury and an artificial airway unable to self-report. Patients with prior brain injuries, cognitive impairment, or any condition (clinical or pharmacological) affecting motor response were excluded. The ESCID-DC was administered 5 min before, during, and 15 min after performing painful procedures (tracheal suctioning, right/left nail bed pressure) and a nonpainful procedure (gauze pad rubbing). All assessments were repeated under deep and light-to-moderate sedation. RESULTS: A total of 418 patients (284 men; 68%) were enrolled. The mean (standard deviation) age was 56.2 (16.3) years. Pain was assessed in 369 patients under deep sedation and in 346 under light-to-moderate sedation. Median (interquartile range) Glasgow Coma Scale scores were 6 (4-7) and 8.5 (7-9) in the deep and light-to-moderate sedation groups, respectively. Under deep sedation, median pain scores during the suctioning and pressure procedures were, respectively, 3 (2-5) and 0 (0-2). Median ESCID-DC scores under light-to-moderate sedation during suctioning and right and left nail bed pressure were 6 (4-7), 3 (1-4), and 3 (1-5), respectively. The ESCID-DC score during the nonpainful procedure was 0. During tracheal suctioning, the discriminative ability of the ESCID-DC was adequate (area under the curve = 0.88; 95% confidence interval: 0.84-0.93), even in patients with very low levels of consciousness. For the pressure procedures, discriminative ability was adequate only when the Glasgow Coma Scale score was ≥5. CONCLUSIONS: The discriminative ability of the ESCID-DC depends on the level of consciousness and type of procedure. In patients with a low level of consciousness, the scale has a limited capacity to detect pain during less painful procedures.