An Overview of Type B Lactic Acidosis Due to Thiamine (B1) Deficiency

Type B lactic acidosis can occur secondary to several factors, including thiamine deficiency, and is not as common as type A. Recognizing thiamine deficiency–associated lactic acidosis is challenging because serum thiamine concentrations are not routinely obtained, and a thorough and specific history is necessary for clinicians to suspect thiamine deficiency as a root cause. Furthermore, the appropriate dose and duration of thiamine treatment are not well defined. Untreated thiamine deficiency–associated lactic acidosis can lead to critical illness requiring lifesaving extracorporeal therapies. Additionally, if thiamine and glucose are not administered in an appropriate sequence, Wernicke encephalopathy or Korsakoff syndrome may occur. This review aims to summarize therapeutic treatment for thiamine deficiency–associated lactic acidosis, based on case reports/series and nutritional guidance. After a literature search of the PubMed database, 63 citations met inclusion criteria, of which 21 involved pediatric patients and are the focus of this review. ­Citations describe dosing regimens ranging from 25 to 1000 mg of intravenous (IV) thiamine as a single dose, or multiple daily doses for several days. Specific guidance for critically ill adults recommends a thiamine range of 100 mg IV once daily to 400 mg IV twice daily. Although there are no specific recommendations for the pediatric population, given the relative safety of thiamine administration, its low cost, and our review of the literature, treatment with thiamine 100 to 200 mg IV at least once is supported, with ongoing daily doses based on clinical response of the patient, regardless of age.