Intradialytic Changes in Blood Pressure and Plasma Catecholamine Levels in Patients on Maintenance Hemodialysis

To investigate the correlation between peripheral catecholamine levels and hypotension often encountered during hemodialysis, we measured blood pressure and plasma levels of norepinephrine (NE), epinephrine (E), and dopamine (DA) before, during, and after hemodialysis in patients with renal failure. Subjects included 37 patients with chronic renal insufficiency whose blood pressure increased, was stable, or decreased during hemodialysis. Patients were then divided into three groups on the basis of changes in either systolic blood pressure (SBP) or diastolic blood pressure (DBP). Changes in plasma catecholamine levels were investigated by comparing data in these increase, stable and decrease groups in both SBP-and DBP-based classifications. Blood was collected before, during, and after hemodialysis, and catecholamine levels were determined with high-performance liquid chromatography / electrochemical detection. Levels of NE tended to decrease during hemodialysis in the increase groups, did not change significantly in the stable groups, and increased, although not significantly, in the decrease groups, in about half of the patients in both the SBPand DBP-based classifications. Levels of E and DA did not show any clear correlation with changes in blood pressure and tended to decrease during hemodialysis. Passage through the dialyzer decreased plasma levels of catecholamines by 48 % to 74 %. In summary, in spite of the transient removal of plasma catecholamines by hemodialysis, NE levels tend to decrease in patients in whom blood pressure increases during dialysis and remain stable in patients in whom blood pressure is stable or decreases. Our results suggest that the sympathetic nervous system is activated in response to blood pressure changes during hemodialysis.