Thiamine Administration and Prevalence of Delirium in the Intensive Care Unit: A Before-after Study

Delirium is a very common condition among ICU-admitted patients, and its prevalence is estimated between 30-40%. Delirium is associated with increased morbidity and mortality and future cognitive decline, along with increased ventilation-dependency and other complications. There are multiple risk factors for delirium, including deficiencies of micronutrients. Thiamine deficiency is associated with specific neurological syndromes, including Wernicke and Korsakoff syndromes and Delirium Tremens. Several studies demonstrated significant thiamine deficiency among ICU-admitted patients (prevalence of 30-70%) without known risk factors, such as alcohol dependency. Thiamine deficiency may cause delirium in those patients. Intravenous thiamine had been safely used for decades, for several indications. Lately, thiamine has been advocated for therapy in patients with septic shock, and its use in intensive care units has increased worldwide. Since 2016, thiamine has been routinely administered in our intensive care unit. Considering the theoretical association between thiamine deficiency and ICU-related delirium, the investigators aim to investigate whether the routine use of thiamine has been associated with decreased prevalence of delirium among ICU patients when compared to the pre-routine thiamine administration era.