Nutritional status and hyperglycemia in the peritransplant period: a review of associations with parenteral nutrition and clinical outcomes.

Hematopoietic stem cell transplantation is an established treatment option for various hematological diseases. This therapy involves complex procedures and is associated with several systemic complications. Due to the toxic effects of the conditioning regimen used in allogeneic transplantations, patients frequently suffer from severe gastrointestinal complications and are unable to feed themselves properly. This complex clinical scenario often requires specialized nutritional support, and despite the increasing number of studies available, many questions remain regarding the best way to feed these patients. Parenteral nutrition has been traditionally indicated when the effects on gastrointestinal mucosa are significant; however, the true benefits of this type of nutrition in reducing clinical complications have been questioned. Hyperglycemia is a common consequence of parenteral nutrition that seems to be correlated to poor transplantation outcomes and a higher risk of infections. Additionally, nutrition-related pre-transplantation risk factors are being studied, such as impaired nutritional status, poorly controlled diabetes mellitus and obesity. This review aims to discuss some of these recent issues. A real case of allogeneic transplant was used to illustrate the scenario and to highlight the most important topics that motivated this literature review.