Validation of a Behavioral Pain Scale in Critically Ill, Sedated, and Mechanically Ventilated Patients

Abstract

Assessing pain in critically ill patients, particularly in nonverbal patients, is a great challenge. In this study, we validated a behavioral pain scale (BPS) in critically ill, sedated, and mechanically ventilated patients. The BPS score was the sum of 3 subscales that have a range score of 1-4: facial expression, upper limb movements, and compliance with mechanical ventilation. Two assessors observed and scored pain simultaneously with the BPS at rest and during painful procedures. The psychometric properties of the BPS that were studied were reliability, validity, and responsiveness. We achieved 360 observations in 30 patients. The BPS was internally reliable (Cronbach alpha = 0.72). The intraclass correlation coefficient to evaluate inter-rater reliability was high (0.95). Validity was demonstrated by the change in BPS scores, which were significantly higher during painful procedures, with averages of 3.9 +/- 1.1 at rest and 6.8 +/- 1.9 during procedures (P < 0.001), and by the principal components factor analysis, which revealed a large first-factor accounting for 65% of the variance in pain expression. The BPS exhibited excellent responsiveness, with an effect size ranging from 2.2 to 3.4. This study demonstrated that the BPS can be valid and reliable for measuring pain in noncommunicative intensive care unit patients.

Analgesia e sedação em unidade de terapia intensiva

“…Pain and sedation assessment is particularly complex in an ICU, as the patients are very often incapable or unable to verbally communicate with the professionals 4,11,13-15 . The patient cannot establish communication with the professionals due to several reasons: tracheal intubation, alteration of consciousness, sedation, and effect of medications 11 .…”

“…However, these alterations have little specificity at the ICU and can be caused by vasopressors, betaadrenergic blockers, anti-arrhythmic drugs, sedatives and pathological conditions (sepsis, shock, hypoxemia and fear) 11 .…”

“…The facial expression is the item that contributes the most to pain assessment, followed by limb movement and acceptance of ventilation 11 . The following are pain behaviors: grimacing, frowning, rigidity, tightly closed eyelids, wrinkling the nose, elevated upper lip, verbalization, and closed fists 11 .…”

“…The following are pain behaviors: grimacing, frowning, rigidity, tightly closed eyelids, wrinkling the nose, elevated upper lip, verbalization, and closed fists 11 . The acceptance of the mechanical ventilation can be affected by hypoxemia, bronchospasm and secretion 11 .…”

Measuring facial grimacing for quantifying patient agitation in critical care

“…Furthermore, in the case of paraplegic patients [16], whole body movement is not available, significantly hindering the use of [9,10]. Facial expression is also particularly important for measuring pain in pediatrics [17][18][19][20], is one of the key elements of Behavioural Pain Assessment [21] and is a significant part of pain measurement in general [22][23][24][25].…”