Aetiology and factors affecting outcome in patients admitted to medical intensive care unit with delirium in a tertiary care teaching hospital

Background: Delirium, a common manifestation in critically ill patients is a strong predictor of prolonged intensive care unit (ICU) stay, higher morbidity and mortality. Methods: One hundred patients admitted to medical ICU (MICU) at our tertiary care teaching hospital with delirium were evaluated using confusion assessment method. Their Simplified Acute Physiology score II (SAPS II) at presentation, socio-demographic details, risk factors for development of delirium were recorded; aetiology and factors affecting outcome were identified. Results: Their mean age was 48.1 ± 16.6 years; there were 63 males. Most of them (87%) belonged to lower socioeconomic status. Infections (65%) followed by intentional poisonings (19%), metabolic causes (10%) and substance abuse (6%) were the important aetiological causes. Hyperactive delirium (48%) was the most common, followed by mixed (27%) and hypoactive delirium (25%). Univariate analysis showed that non-survivors had a significantly higher SAPS II (p<0.001) and a higher burden of chronic kidney disease (p<0.001) compared to survivors. Conclusion: Knowledge of the factors influencing delirium will increase our ability for early detection and prevention of delirium.