Abstract
Introduction: Raising or lowering blood pressure and muscle cramps are the main barriers
for dialysis. Meanwhile, lowering blood pressure is more common and its mechanism is
somewhat clear. But the mechanism for increasing blood pressure is not yet clear fully.
Objectives: In this study, we examined the prevalence of intradialytic hypertension (IDH)
and its related factors, especially changes in plasma renin activity, hematocrit, heart rate, and
electrolytes in end-stage renal disease (ESRD) patients undergoing chronic hemodialysis.
Patients and Methods: In a cross-sectional study, patients with chronic end-stage renal
disease under chronic hemodialysis were included to the study in the absence of a specific
infection, as well as in lack of intravenous fluid providing during dialysis due to hypotension.
Blood pressure and heart rate before and after hemodialysis were measured in four consecutive
dialysis sessions. Elevating mean arterial blood pressure by 15 mm Hg between beginning
and end of dialysis or raising blood pressure within four consecutive dialysis sessions were
considered as IDH.
Results: Around 17 of the 88 (19.3%) patients with hemodialysis had IDH. These subjects
were compared with non-IDH patients who were similar in age and gender. The most
common underlying disease in both groups was diabetes mellitus followed by hypertension.
Comparison of measured parameters before and after dialysis showed that serum potassium
level was significantly decreased in both groups. Serum sodium level increased in both
groups, but this increase was significant only in the control group. There were no significant
changes in renin plasma activity, heart rate and hematocrit levels in both groups.
Conclusion: In this study, plasma renin activity in IDH group increased after dialysis
compared to pre-dialysis. This finding requires to more test with larger sample size.