| Popis: |
In 9 chronic hemodialysis patients, treated with recombinant human erythropoietin (rHuEpo), longitudinal studies were performed to investigate possible changes in macro- and microcirculatory parameters during normovolemia, as assessed echographically by determining the inferior vena cava diameter and adjusting dialysis dry weight. Hematocrit increased from 19 +/- 4 to 33 +/- 5% (p less than 0.001). Systemic vascular resistance increased from 1,020 +/- 259 to 1,283 +/- 245 dyn/s/cm-5 (p less than 0.02), while mean arterial pressure remained unchanged. Cardiac index decreased (4.9 +/- 1.4 to 3.8 +/- 0.9 liters/min/m2; p less than 0.02), caused by a decrease in heart rate (87 +/- 21 to 75 +/- 16 beats/min; p less than 0.02) and stroke index (59.9 +/- 15.2 to 51.0 +/- 10.7 ml/m2; p less than 0.02). Red blood cell volume increased (468 +/- 105 to 858 +/- 203 ml/m2; p less than 0.001) and plasma volume decreased inversely ([125I]-albumin; 2,008 +/- 338 to 1,664 +/- 225 ml/m2; p less than 0.001), whereas total blood volume remained unaltered (2,476 +/- 397 to 2,518 +/- 352 ml/m2; n.s.). Total body weight increased (57.8 +/- 12 to 62.1 +/- 12 kg; p less than 0.02), indicative of an anabolic effect of rHuEpo therapy. Skin capillary circulation as measured by transcutaneous oxymetry at 37 degrees C skin temperature impaired, reflected by the increase of the time to peak after arterial occlusion (82 +/- 21 to 121 +/- 25 s; p less than 0.02). The reactive hyperemic response following the release of occlusion showed a significant increase at high hematocrit (10.7 +/- 4.2 to 16.6 +/- 5.3 mm Hg; p less than 0.02), whereas resting transcutaneous Po2 values showed a slight but not significant increase (2.3 +/- 1.3 to 4.7 +/- 3.3 mm Hg; n.s.). The high number of pathological capillaries in hemodialyzed patients might be an additional factor for the increase in systemic vascular resistance. |
