Study of the Effect of Intradialytic Vasopressin on Chronic Hypertension in Patients With End Stage Renal Disease

The death rate of patients with endstage renal disease (ESRD) on dialysis each year is 20%,
with diseases related to the heart and blood vessels causing about half. About 60% of
patients on hemodialysis have high blood pressure, which is poorly controlled in most. Normal
blood pressure in these patients greatly improves the chance of living. Increased fluid in
the body and bloodstream is a major cause of hypertension in patients with ESRD. Fluid
removal during hemodialysis is often limited by symptoms of low blood pressure during the
procedure. Therefore the increase in fluid and related high blood pressure is ongoing for
many of these patients. Arginine vasopressin (AVP) is a hormone naturally produced by the
body which has little effect on blood pressure in healthy people, but acts as a powerful
vasoconstrictor (narrows the blood vessels) when blood pressure is threatened. Recent studies
have shown when there is too little AVP, patients are more likely to have low blood pressure
during dialysis that limits fluid removal, an effect that can be reversed by giving these
patients low doses of AVP. This phase II trial will find out which of two doses of AVP (.15
or .30 mU kg-1 min-1), in combination with standard therapy, works best to change
interdialytic 44-hour ambulatory systolic blood pressure after 2 weeks. Patients who enroll
in this study will be divided into three groups. One group will be given a 0.15 mU kg-1 min-1
dose of AVP at each dialysis session over a 2-week period; the second group will be given AVP
0.3 mU kg-1 min-1 at the same interval; and a third group will be given normal saline
(placebo) at the same interval. All patients will be closely monitored for side-effects.