Is there a role for intradialytic parenteral nutrition? A review of the evidence.

Protein-energy wasting (PEW) is highly prevalent in people with stages 4 and 5 chronic kidney disease, particularly in maintenance dialysis patients, and many indicators of PEW correlate strongly with mortality. Consequently, the causes, prevention, and treatment of PEW are active areas of investigation. A major cause of PEW is insufficient intake of nutrients, especially protein and energy (calories). Standard methods for increasing nutritional intake in patients with chronic kidney disease with PEW include dietary counseling and use of food supplements. If nutrient intake does not increase sufficiently, tube feeding and total parenteral nutrition may be considered. For maintenance hemodialysis patients, intradialytic parenteral nutrition (IDPN), an intravenous infusion of essential nutrients during hemodialysis treatments, may be used. Many studies have evaluated the effectiveness and safety of IDPN and show that IDPN has a good safety profile and also may improve protein-energy status. However, most studies have limitations in experimental design, such as small numbers of patients, lack of adequate controls, inclusion of patients without PEW, uncontrolled or unmonitored oral intake, nonrandomized design, or short duration. Additionally, most studies used nutritional or inflammatory indicators, rather than the more important outcomes of morbidity, mortality, or quality of life. Thus, although IDPN may partially satisfy the nutritional needs of maintenance hemodialysis patients who have or are at risk of PEW and who have substantial, but not adequate, protein and/or energy intake, longer term randomized prospective clinical trials with appropriate control groups are necessary to more definitively evaluate the clinical effectiveness and indications for IDPN.