Elsevier

Kidney International

Volume 41, Issue 5, May 1992, Pages 1286-1291
Kidney International

Clinical Investigation
Survival as an index of adequacy of dialysis

https://doi.org/10.1038/ki.1992.191Get rights and content
Under an Elsevier user license
open archive

Survival as an index of adequacy of dialysis. To examine how patient survival substantiates dialysis adequacy, 20-year actuarial survival experience was calculated for 445 unselected hemodialysis (HD) patients (97 patients accepted on a temporary basis—and usually kept on their regular dialysis scheme—were left out). The dose of dialysis has been the same and unchanged for all patients since beginning: 24 square meter hours of, Kiil dialysis (cuprophane) per week with acetate buffered dialysate. KT/V mean (SD) was 1.67 (0.41). Six months after starting dialysis, 98% of patients were normotensive and off all blood pressure (BP) medication. The mean population hematocrit, excluding the only 6 patients receiving eryhropoietin supplementation, was 28%. Survival rate was 87% at 5 years, 75% at 10 years, 55% at 15 years, and 43% at 20 years of HD. The satisfactory control of BP without using potentially toxic BP drugs and the higher than usual dose of dialysis are two possible explanations for survival data better than usually reported. We suggest that patient survival should be considered as the best overall index of adequacy of dialysis.

Cited by (0)

Editorial: Adequate control of blood pressure in patients on chronic hemodialysis. Shortly after our first patient, Mr. Clyde Shields, began long term hemodialysis in March of 1960, he developed malignant hypertension, and death seemed imminent [1], Since we were unable to control his blood pressure with the few antihypertensive drugs then available, we decided that our only hope of saving him was to try aggressive removal of extracellular fluid by ultrafiltration during his once weekly 24-hour hemodialysis [1]. During the subsequent weeks cramping was severe as we tried to maximize fluid removal during each dialysis. Gradually, however, his blood pressure came under control. Eventually he became normotensive off medication, and remained so until his death from a myocardial infarction in 1971. This dramatic episode made a lasting impression on our approach to the control of blood pressure in our hemodialysis patients. Even after effective antihypertensive medications became available, we continued to make control of the extracellular volume (ECV) the cornerstone of treatment of hypertension in our dialysis population.

The first published validation of this approach came in 1983 from Charra and his colleague in Tassin, France [2]. This same group now publishes in this article impressive evidence that this approach to control of blood pressure not only works in 98% of the 445 hemodialysis patients in their series, but is the major factor accounting for the excellent patient survival they report.

The rationale for using control of ECV to maintain normal blood pressure in the dialysis population can be summarized as follows: (1) Hypertension in these patients is volume dependent. (2) Even small increments in ECV can cause significant increases in the resistance to antihypertensive medications. (3) This effect leads to the use of larger doses of antihypertensive medications. (4) The presence of large amounts of these medications makes fluid removal during hemodialysis more difficult because of hemodynamic instability. (5) This problem can result in further increases in the ECV and even greater resistance to blood pressure control.

In our experience, severe hypertension poorly controlled by drugs most often is seen in patients who are just starting hemodialysis. In such instances, it usually takes several weeks or months of aggressive ultrafiltration combined with gradual withdrawal of antihypertensive drugs to obtain control of blood pressure off medications. During this transition period, it requires patience and persistance on the part of the dialysis staff, and willingness to tolerate occasional episodes of cramping and hypotension on the part of the patient. Furthermore, if the patient cannot comply with a no added salt diet, control of blood pressure using ultrafiltration without drugs becomes more difficult as the sodium intake increases.

The excellent survival results presented in this issue by Charra et al provide strong additional support for the concept that normalization of blood pressure in the dialysis patient delays or prevents death from the complications of atherosclerosis. Adequate control of blood pressure now must become a part of the definition of adequacy of dialysis along with an adequate dose of dialysis and adequate intake of protein.

Belding H Scribner

Seattle, Washington

References

1. SCRIBNER BH: A personalized history of hemodialysis. Am J Kid Dis 16:511–519, 1990

2. CHARRA B, CALEMARD E, CUCHE M, LAURENT G: Control of hypertension and prolonged survival on maintenance hemodialysis. Nephron 33:96–99, 1983