Total parenteral nutrition and hematopoietic stem cell transplantation: an expensive placebo?

A majority of patients undergoing hematopoietic stem cell transplantation (HSCT) suffer from severe mucositis and enteritis due to cytotoxic therapy and immune dysregulation, resulting in prolonged decreased oral intake, nausea, vomiting and diarrhea. While total parenteral nutrition (TPN) is often given to patients in order to maintain their nutritional status during the peritransplant period, there is conflicting evidence to support its routine use. We evaluated the small number of prospective randomized and nonrandomized controlled trials that assessed important clinical outcomes such as time to engraftment, rates of infection, overall survival and length of hospitalization. We believe that the data do not support the routine use of parenteral nutrition as first-line therapy but should be reserved for those patients who are unable to tolerate enteral feedings. We also believe that glutamine supplementation cannot be recommended to all HSCT recipients as it has been shown to increase morbidity and mortality rates in autologous transplant patients. Further investigations that test accurate monitoring assessments and incorporate specific substrates such as lipids with parenteral and enteral nutrition are warranted. Novel therapies such as recombinant human keratinocyte growth factor and glucagon-like peptide show future promise in modulating the severity and duration of mucositis, minimizing further the need for TPN.