A prospective cohort study on predictors of mortality of delirium in an emergency observational unit

Delirium is often an underdiagnosed and underestimated neuropsychiatric syndrome, especially in low- and middle-income countries.

To document the prevalence and clinical profile of delirium and to detect the baseline parameters associated with in-hospital mortality.

A prospective cohort study conducted between January 2016 to December 2016 at an adult medical emergency observational unit of an academic hospital in north India.

Confusion Assessment Method for the intensive care unit was used for screening and diagnosis of delirium. Subtypes of delirium and severity were defined with the Richmond agitation-sedation scale and Delirium Rating Scale-Revised-98 (DRS-R-98).

Out of 939 screened patients, 312 (33.2%) had delirium, including 73.7% unrecognized cases. The mean age was 49.1 ± 17.3 years (range 17-90), and only 33.3% of the patients were above 60 years. The prevalence of hypoactive, mixed and hyperactive delirium was 39.1, 33.7 and 27.2%, respectively. Usual predisposing factors were alcohol use disorder (57.4%) and hypertension (51.0%), and infections remain the most common precipitating factors (42.0%). In total, 96.1% of patients received midazolam before delirium onset, and physical restraints were used in 73.4%. Mortality was higher in delirium (19.9% vs. 6.4%). The independent predictors of death in delirium were low diastolic blood pressure (P-value = 0.000), Glasgow coma scale score <15 (P = 0.026), high Acute Physiology and Chronic Health Evaluation II score (P = 0.007), high DRS-R-98 severity score (P = 0.000) and hyperactive delirium (P = 0.024).

Rapid screening with Confusion Assessment Method for the intensive care unit detected a high prevalence of delirium (even in young patients), and it associated with high mortality.