Thiamine supplementation in the critically ill

PURPOSE OF REVIEW: To summarize the properties of thiamine and evaluate current evidence on thiamine status and supplementation, for different populations of critically ill patients. RECENT FINDINGS: Thiamine, in the form of thiamine pyrophosphate, is a critical co-factor in the glyocolysis and oxidative decarboxylation of carbohydrates for energy production. Different studies have shown that critical illness in adults and children is characterized by absolute or relative thiamine depletion, which is associated with an almost 50% increase in mortality. Thiamine deficiency should be suspected in different clinical scenarios such as severe sepsis, burns, unexplained heart failure or lactic acidosis, neurological disorder in patients with previous history of alcoholism, starvation, chronic malnutrition, long-term parenteral feeding, hyperemesis gravidarum, or bariatric surgery. Nonetheless, thiamine supplements are not routinely given to critically ill patients. Clinicians should be able to suspect and recognize risk factors for the occurrence of severe neurological disorders secondary to thiamine deficiency, as early treatment can prevent the appearance of permanent neurological damage. SUMMARY: Symptoms and signs associated with thiamine deficiency lack sensitivity and specificity in critically ill patients. Consequently, depletion is frequently unrecognized and underdiagnosed by clinicians. Potentially deleterious consequences of thiamine depletion should be avoided by early and appropriate supplementation.