Dogma and the Renal Patient

Abstract

Nutrition care of the patient with renal disease is relatively complex, given the significant number of potential metabolic derangements seen in this population. Many clinicians describe a high level of uncertainty regarding care for patients with either acute or chronic renal failure. Professionals attempting to care for these patients should be able to turn to the medical literature for guidance in making rational, appropriate decisions regarding this care. Unfortunately, the nephrology literature is rife with articles purporting to represent evidence-based recommendations, when in fact the conclusions made are the opinion of the author(s). The initial fault in the nephrology literature is a lack of controlled trials of significant size and design to allow for conclusions regarding patient care to be drawn. This deficiency was most apparent in the publication of the Kidney Disease Outcomes Quality Initiative (K/DOQI) by the National Kidney Foundation. This initiative represented an exhaustive review of the nephrology literature in a number of areas of care of the renal patient, including nutrition. However, the result of this review was both a dearth of evidence-based guidelines and the repeated request for more research to be performed. The K/DOQI guidelines for nutrition, for example, contained 22 of 27 guidelines that were, at least in part, opinion based. Given the lack of a literature basis for evidencebased nephrologic practice, authors of review articles will have a tendency to pursue 1 of 2 approaches. One approach results in the presentation of as complete a description of the disease process as possible, with a rational approach to evaluation or treatment offered as an option. The alternative is a presentation fostering a specific opinion as the only interpretation, regardless of the evidence or lack thereof. In this issue of Nutrition in Clinical Practice, we provide an overview of issues and controversies associated with provision of nutrition support to patients with acute and chronic renal failure. An expert panel of authors provides the reader with information pertinent to everyday care of these complex patients. There is still so much that we don’t know about the impact of our nutrition interventions on outcomes in acute renal failure (ARF). We know that nutritional status is an important prognostic indicator in maintenance hemodialysis (MHD), but we still don’t have the definitive standards to determine nutritional status. It’s time to reevaluate the paradigms now entrenched in practice. Is albumin the definitive marker of nutritional status in MHD patients? Is intradialytic parenteral nutrition (IDPN) safer and more effective than enteral nutrition, or are we treating a clinician bias against enteral feeding? What is the optimum protein intake for ARF, and do we need to consider specific amino acids as being essential for these very sick patients? Finally, is carnitine deficiency widespread in this population, or can these patients synthesize adequate amounts?