RESUMO
BACKGROUND: Thiamine plays a critical role in energy metabolism. Critically ill patients may have thiamine deficiency and increased mortality due to potentially irreversible consequences. The aim of this study was to show the impact of thiamine deficiency in a series of patients and the rapid response to thiamine replacement, showing the changes in clinical and metabolic conditions over time. METHODS: We described 3 cases of hospitalized patients who had received parenteral nutrition (PN) without vitamin supplementation. All the patients were admitted to the ICU between 2010 and 2011 with a severe form of lactic acidosis, an unstable circulatory state, and a different neurological disorder (a lethargic state, a severe form of impaired near-coma consciousness, and Wernicke encephalopathy). RESULTS: Intravenous (IV) administration of thiamine was associated with a rapid and marked restoration of acid-base balance, hemodynamic stability and the disappearance of neurological disturbances, and normalization of the clinical and biochemical conditions of all the patients within the following hours. CONCLUSIONS: The 3 cases demonstrated the rapidity of the reversal of severe thiamine deficiency, achieved by appropriate replacement in different hospitalized patients. The regression of clinical and biochemical disorders requires a prompt diagnosis and treatment based on the IV administration of thiamine and magnesium sulfate. In hospitalized patients at risk, thiamine deficiency is prevented by the integration of thiamine supplementation into PN and other forms of nutrition support.