CPOT-Neuro

The CPOT-Neuro is an adaptation of the original CPOT. The original tool [3] includes five behavioral items: (a) facial expression, (b) body movements, (c) compliance with ventilator (mechanically ventilated patients) or (d) vocalization (non-intubated patients), and (e) muscle tension. Each item is scored from 0 to 2 for a possible total score from 0 to 8. A higher score reflects more intense behavioral reactions, and a cut-off score ≥  2 indicates the presence of pain [10, 11, 23, 29].

In the adaptation process, each item and score of the original CPOT were reviewed in accordance with observational data of pain-related behaviors in brain-injured ICU patients [17, 18, 30]. Evaluations of the behaviors’ relevance for pain assessment in this population were also made by 61 ICU nurses, 13 physicians, and 3 physiotherapists [31].

Modifications were made to all items of the tool. Scores of 0 remained unchanged for facial expression, body movements, muscle tension, compliance with the ventilator, and vocalization. For the facial expression item, the score of 1 was modified to only include brow lowering. Brow lowering was identified as a frequent reaction to a painful procedure in brain-injured ICU patients no matter their LOC [17, 18], and considered relevant by ICU clinicians [31]. A score of 2 was modified to include at least two contractions in the patient’s upper face (e.g., brow lowering + eye tightening) or grimace. Grimace is the strongest predictor of pain intensity in this patient group [17] and rated as highly relevant by ICU clinicians [31]. In regard to body movements, scores of 1 and 2 were also operationalized a bit differently. A score of 1 was modified to include non-purposeful movements such as cautious movements or limb flexion. A score of 2 was related to protection or purposeful movements such as trying to reach or touching the pain site which was rated as highly relevant by ICU clinicians [31]. These descriptions of body movements better reflect what was observed in brain-injured ICU patients [17]. In the ventilator compliance item, only the description of score of 1 was modified for activation of alarms. Coughing was removed as it was rated as irrelevant by ICU clinicians [31]. For vocalization, verbal complaints of pain were added in the score of 2 as it was considered relevant by ICU clinicians for brain-injured patients who are conscious or with an altered LOC [31]. The score of 2 (very tense) for muscle tension was removed as it can be confounded with spasticity as a consequence of brain injury as highlighted by ICU clinicians [31]. Autonomic responses related to tearing and face flushing were newly described in brain-injured ICU patients [17, 19]. Autonomic responses were also rated as relevant by clinicians for brain-injured ICU patients who are conscious or with an altered LOC [31]. A score of 1 was assigned in the presence of at least one of these autonomic responses. The total score of CPOT-Neuro may vary from 0 to 8 and remains consistent with the original CPOT total score.

The CPOT-Neuro was initially adapted in French-Canadian from the original CPOT French-Canadian version [32] and then translated into English using a forward–backward translation method. Both the French-Canadian and the English versions of the CPOT-Neuro were validated simultaneously in this study. Description of the CPOT-Neuro can be found in Additional file 1.