In search of an optimal hematocrit level in dialysis patients: rehabilitation and quality-of-life implications.

Anemia is an inevitable and potentially serious complication of chronic renal failure and one of the most important limiting factors in patient rehabilitation. Although adequate dialysis can control many of the symptoms of uremia, dialysis does not reverse anemia-associated fatigue, and thus, many patients are not rehabilitated. Human recombinant erythropoietin (epoetin) therapy has proven to be effective in reversing anemia and increasing hematocrit levels in the majority of patients with chronic renal failure. Among this patient population, increases in hematocrit level have resulted in improvements in the symptomatology of organ hypoxia, neurobehavioral indices, anorexia, insomnia, depression, and sexual disinterest and dysfunction, as well as a reduction in cardiomegaly. However, despite the availability of epoetin and the dramatic improvements in the complications associated with the anemic state observed following therapy, it appears that patient rehabilitation remains a challenge. One aspect of the continuing problem of rehabilitation appears to be the reluctance of the medical community to increase hematocrit levels above 30%, despite the fact that higher hematocrit levels are associated with greater improvements and that potential adverse events related to hemodynamic adaptation are manageable. Indeed, a comparison of the results from two Epoetin alfa clinical trials, one in which hematocrit levels were maintained at 35% and a large phase IV study in which the target hematocrit level appears to have been approximately 30%, clearly demonstrate the benefits of optimizing hematocrit levels and thus improving the potential for rehabilitation.