Objective
Catatonia, a condition characterized by motor, behavioral and emotional changes, can occur during critical illness and appear as clinically similar to delirium, yet its management differs from delirium. Traditional criteria for medical catatonia preclude it’s diagnosis in delirium. Our objective in this investigation was to understand the overlap and relationship between delirium and catatonia in ICU patients and determine diagnostic thresholds for catatonia.
Setting
Convenience cohort, nested within 2 ongoing randomized trials at a single institution.
Patients
We enrolled 136 critically ill patients on mechanical ventilation and/or vasopressors, randomized to two usual care sedation regimens.
Measurements and Main Results
Patients were assessed for delirium and catatonia by independent and masked personnel using Confusion Assessment Method for the ICU (CAM-ICU) and the Bush Francis Catatonia Rating Scale (BFCRS) mapped to DSM-5 criterion A for catatonia. Of 136 patients, 58 (43%) patients had only delirium, 4 (3%) had only catatonia, 42 (31%) had both and 32 (24%) had neither. In a logistic regression model, more catatonia signs were associated with greater odds of having delirium. For example, patient assessments with ≥3 DSM-5 symptoms (75th percentile) had, on average, 27.8 times the odds (IQR 12.7, 60.6) of having delirium compared with patient assessments with 0 DSM-5 criteria (25th percentile) present (p< 0.001). A cut-off of ≥4 Bush Francis Catatonia Screening Instrument (BFCSI) items was both sensitive (91%) 95% CI (82.9 – 95.3) and specific (91%) 95% CI (87.6 – 92.9) for DSM-5 catatonia.
Conclusions
Given that about 1 in 3 patients had both catatonia and delirium, these data prompt reconsideration of DSM-5 criteria for “Catatonic Disorder Due to Another Medical Condition” that preclude diagnosing catatonia in the presence of delirium.