OBJECTIVES - 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 its 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.
DESIGN - Convenience cohort, nested within two ongoing randomized trials.
SETTING - Single academic medical center in Nashville, TN.
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 and the Bush Francis Catatonia Rating Scale mapped to Diagnostic Statistical Manual 5 criterion A for catatonia. Of 136 patients, 58 patients (43%) had only delirium, four (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 greater than or equal to three Diagnostic Statistical Manual 5 symptoms (75th percentile) had, on average, 27.8 times the odds (interquartile range, 12.7-60.6) of having delirium compared with patient assessments with zero Diagnostic Statistical Manual 5 criteria (25th percentile) present (p < 0.001). A cut-off of greater than or equal to 4 Bush Francis Catatonia Screening Instrument items was both sensitive (91%; 95% CI, 82.9-95.3) and specific (91%; 95% CI, 87.6-92.9) for Diagnostic Statistical Manual 5 catatonia.
CONCLUSIONS - Given that about one in three patients had both catatonia and delirium, these data prompt reconsideration of Diagnostic Statistical Manual 5 criteria for "Catatonic Disorder Due to Another Medical Condition" that preclude diagnosing catatonia in the presence of delirium.