Psychiatric-Medical ComorbidityDelirium in patients admitted to a cardiac intensive care unit with cardiac emergencies in a developing country: incidence, prevalence, risk factor and outcome

AimTo assess the incidence, prevalence, risk factors and outcome of delirium in patients admitted to a cardiac intensive care unit (ICU) of a tertiary care hospital.MethodsThree hundred nine consecutive patients admitted to a 22-bed coronary care unit were screened for presence of delirium by using Confusion Assessment Method for Intensive Care Unit (CAM-ICU), and those found positive on CAM-ICU were further evaluated by a psychiatrist to confirm the diagnosis of delirium as per DSM-IV-TR criteria. Patients were also evaluated for the risk factors for delirium and outcome of delirium.ResultsIncidence rate of delirium was 9.27%, and prevalence rate was 18.77%. The risk factors identified for delirium in binary logistic regression analysis were hypokalemia, Sequential Organ Failure Assessment score, presence of cognitive deficits, receiving more than three medications, sepsis, hyponatremia, presence of cardiogenic shock, having undergone coronary artery bypass grafting, left ventricular ejection fraction < 30, currently receiving opioids, age more than 65years, presence of diabetes mellitus, presence of uncontrolled diabetes mellitus, history of seizures, presence of congestive cardiac failure, having undergone angioplasty, presence of atrial fibrillation, ongoing depression, currently receiving/taking benzodiazepines, warfarin, ranitidine, steroids, non-steroidal anti-inflammatory drugs, higher total number of medications, presence of raised creatinine, anaemia, hypoglycemia, Acute Physiology and Chronic Health Evaluation II score and Charlson Comorbidity Index score. About one fourth (n= 22; 27%) of the patients who developed delirium died during the hospital stay in contrast to 1% mortality in the non-delirious group. Those with delirium also had longer stay in the ICU.ConclusionsDelirium is highly prevalent in the cardiac ICU setting and is associated with presence of many modifiable risk factors. Development of delirium increases the mortality risk and is associated with longer cardiac ICU stay.