This study was undertaken to assess the importance of an elevated cardiac output in the generation of the hypertension associated with chronic renal failure. Forty stable uremic patients on a program of maintenance hemodialysis underwent hemodynamic studies. Cardiac index measured by dye dilution was found to be significantly elevated. Calculated peripheral vascular resistance was normal despite elevated blood pressure. Six patients underwent serial hemodynamic studies over a period of 6 to 12 weeks while being transfused with packed red blood cells to a normal hematocrit. Blood volume and body weight were constant during the study period. Cardiac index decreased during transfusion, reaching a normal level at a hematocrit of 30%. Diastolic blood pressure progressively rose, averaging an increase of 20 mm Hg at a hematocrit of 40%. Peripheral vascular resistance increased by 80% at a hematocrit of 40%. We concluded that the elevation of cardiac index in uremic patients is secondary to anemia and is reversible when the hematocrit is raised over 30%. The high cardiac index is not responsible for hypertension because restoration of cardiac index to normal by transfusion raises blood pressure rather than lowers it.

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To compare the erythropoietic effects of nandrolone decanoate, testosterone enanthate, oxymetholone, and fluoxymesterone, we performed a randomized clinical trial in patients with anemia who were receiving maintenance hemodialysis (the women were not given testosterone enanthate). After a control period of at least two months, patients received one of the drugs for six months and then returned to control status; a second and third drug were administered in a similar fashion. Seventy-seven patients completed the first drug period, 56 the second, and 35 the third. The response to nandrolone and testosterone enanthate, the two drugs given by injection, was clearly superior to the response to oxymetholone or fluoxymesterone, given by mouth, in terms of the percentage of patients responding and the mean rise in hematocrit. Approximately half the patients had an increase of at least 5 percentage points in hematocrit after an injectable androgen was given; more than half the women responded. Patients who required transfusions regularly and those who had bilateral nephrectomies did not respond.

We studied 10 patients during acetate and 10 patients during bicarbonate hemodialysis to assess changes of minute ventilation; oxygen consumption (VO₂); and carbon dioxide production (VCO₂) as well as pO₂, pCO₂ and pH. We also measured the extent of pulmonic shunting by administering 100% O2. Our studies revealed that VO₂ increased significantly during acetate dialysis, while it decreased slightly during bicarbonate dialysis. Since VCO₂decreased with both baths, the respiratory exchange ratio (R) decreased during acetate dialysis but did not change during bicarbonate dialysis. By the alveolar gas equation, these changes in R could account for a difference in alveolar PO₂ and consequently arterial pO₂ The fact that pO₂ fell during bicarbonate dialysis may relate to decreased minute ventilation paralleling decreases in VCO₂. The degree of intrapulmonic shunting was not altered during dialysis with either bath. We conclude that hypoxemia during dialysis relates to decreases in minute ventilation and that a greater decrease during acetate dialysis is a consequence of enhanced VO₂ and its effect on R. Bicarbonate dialysis does not increase VO₂.

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