No abstract

End-stage renal disease patients displayed increases in resting energy expenditure over the predicted values derived using normal populations. Resting energy expenditure was significantly higher in patients receiving dialysis, regardless of the modality, than patients with chronic renal failure. Daily energy intake was substantially less than required in all patient groups studied, suggesting that patients with renal failure could develop protein-calorie malnutrition because of increased resting energy expenditure, which is exacerbated by dialysis.

The decision to initiate dialysis in a patient with progressive renal disease often depends on the physician's assessment of the patient's subjective symptoms of uremia. There is an increasing need to identify objective criteria for such a decision. Recent evidence suggests that malnutrition at the initiation of dialysis is a strong predictor of subsequent increased relative risk of death on dialysis. In this context, the role of prescribed protein restriction as well as the influence of the progression of renal disease on spontaneous dietary protein intake is examined. It is proposed that the indices of malnutrition such as progressive weight loss, serum albumin levels below 4.0 g/dL, serum transferrin levels below 200 mg/dL, and spontaneous dietary protein intake (using 24-hr urinary nitrogen measurement) below 0.8 to 0.7 g/kg per day be considered as objective criteria for the initiation of dialysis. Studies that have examined the role of "early" versus "late" dialysis have consistently shown a better outcome in the patients starting dialysis early. Other studies also suggest that early referral to nephrologists results in improved morbidity and mortality as well as hospitalization costs. An adequate vascular access, as well as social and psychological preparation of the patient, is an important early step in the process.

No abstract

The immune response requires the coordinated release of a network of cytokines including interleukin-1 (IL-1), tumor necrosis factor (TNF), and IL-2. The potential role of the dialysis membrane on the elaboration of these cytokines by peripheral blood mononuclear cells (PBMNC) harvested from hemodialysis patients was investigated in a prospective crossover study. Eight hemodialysis patients, chronically dialyzed with a biocompatible membrane, were sequentially dialyzed for 2 wk with new cuprophane membranes (Phase I), 2 wk with a low-flux, low-complement-activating membrane (Phase II), and then switched back for a further 2 wk of dialysis with a cuprophane membrane (Phase III). At the end of 2 wk of exposure to the cuprophane membrane, during both Phase I and Phase III, the ability of PBMNC to elaborate IL-1 beta, tumor necrosis factor-alpha, and IL-2, as well as soluble IL-2 receptors, in response to phytohemagglutinin was significantly reduced compared with their respective levels at the beginning of the phase; dialysis with a biocompatible membrane increased these levels, and at the end of 2 wk, the response of the PBMNC to phytohemagglutinin was close to that in normal controls. These findings may explain some of the conflicting results in the measurement of cytokine levels in hemodialysis patients and may have clinical implications.