WERNICKE-KORSAKOFF SYNDROME AS A NEGLECTED CAUSE OF DELIRIUM IN THE INTENSIVE CARE UNIT: PATHOPHYSIOLOGY OF ALCOHOL AND THIAMINE DEFICIENCY IN DELIRIUM IN CRITICALLY ILL PATIENTS

Abstract

Introduction: Delirium in the Intensive Care Unit (ICU) is an acute brain dysfunction with a high impact on mortality. Wernicke-Korsakoff Syndrome (WKS), resulting from thiamine (vitamin B1) deficiency, is a frequently neglected and underdiagnosed cause in this setting. Objective: To analyze WKS as a cause of delirium in critically ill patients, investigating the pathophysiology of thiamine deficiency and the influence of alcohol. Methods: An integrative literature review was conducted using the PubMed, SciELO, LILACS, BVS, and UpToDate databases, encompassing publications between 2020 and 2026. Forty-five records were selected for analysis. Results: The prevalence of thiamine deficiency in critically ill patients reaches 30%, being exacerbated by sepsis and chronic alcoholism, which alters brain transporters (THTR-2). Doses lower than 500 mg IV three times a day are insufficient in the presence of neuroinflammation. The use of glucose without prior thiamine replacement poses a serious iatrogenic risk. Discussion: SWK should be treated as a metabolic emergency. The low sensitivity of the classic clinical triad requires a high index of suspicion and empirical treatment. Early supplementation presents an excellent cost-benefit ratio and neuroprotective safety. Conclusion: Mitigating nutritional delirium requires aggressive replacement protocols and integration between nutrition and intensive care medicine to prevent permanent neurological sequelae and post-ICU dementia.