INCREASED NITRIC-OXIDE PRODUCTION IN PATIENTS WITH HYPOTENSION DURINGHEMODIALYSIS

Objective: To determine the involvement of nitric oxide production in hemodialysis-induced hypotension. Design: Examination of nitric oxide synthesis, cyclic guanosine 3'5'-monophosphate (cGMP) levels, and endo thelin-1 levels in plasma before and after hemodialysis. Setting: Vete rans Affairs medical center. Patients: 13 patients with end-stage rena l failure who were receiving hemodialysis: Six patients had hypotensiv e episodes during dialysis and 7 did not. Intervention: Patients recei ved heparin at a bolus dose of 2000 U at the initiation of dialysis fo llowed by 1000 U/h during 4-hour hemodialysis sessions. Results: Nitri c oxide production markedly increased during hemodialysis-induced hypo tensive episodes; this increase was not seen in patients who did not h ave a hypotensive episode. In both groups, the plasma cGMP and endothe lin-1 levels decreased after hemodialysis. According to multiple regre ssion analysis, standard coefficients of nitric oxide production, plas ma cGMP levels, and endothelin-1 levels with mean blood pressure after hemodialysis were -0.743, -0.07, and 0.31, respectively. Conclusion: Nitric oxide production increased in patients who had a hypotensive ep isode during hemodialysis but did not increase in those who did not ha ve a hypotensive episode.