Role of nitric oxide in haemodialysis hypotension

Abstract

To investigate the possible involvement of nitric oxide (NO) in haemodialysis hypotension, we measured plasma concentrations of nitrate anion (NO3-), a metabolite of NO, in 114 patients undergoing maintenance haemodialysis. Mean plasma NO3- concentrations before dialysis were greater in subjects with lower blood pressure (155 +/- 16 micromol L-1) than in those with middle (117 +/- 8 micromol L-1) or higher blood pressure (105 +/- 12 micromol L-1) before dialysis. Further, mean plasma NO3- concentrations before dialysis were greater in subjects with lower blood pressure (186 +/- 13 micromol L-1) than in those with middle (112 +/- 7 micromol L-1) or higher blood pressure (64 +/- 11 micromol L-1) after dialysis. Plasma NO3- concentrations before dialysis were inversely correlated with mean blood pressure before dialysis (r=0.318, P=0.0006), and showed a strong inverse correlation with mean blood pressure after dialysis (r=0.608, P=0.0001). In the selected participants who had equal range of mean blood pressure before dialysis, mean plasma NO3- concentrations were greater in subjects with severe hypotension during dialysis (180 +/- 14 micromol L-1) than in those with mild hypotension (99 +/- 11 micromol L-1) or without hypotension (53 +/- 12 micromol L-1); plasma NO3- concentrations before dialysis were inversely correlated with changes in mean blood pressure during dialysis and mean blood pressure after dialysis. Results indicate that enhanced NO production may be involved in acute hypotension during dialysis, and suggest the possible involvement of NO in the pathogenesis of chronic hypotension associated with maintenance haemodialysis.

Nitric Oxide Synthetic Capacity in Relation to Dialysate Temperature

“…Still, the fact that various authors have reported that NO is related to hemodialysis hypotension [11][12][13][14]17] suggests that our findings might contribute to the understanding at a more basic level for the apparent relation between hemodynamic stability and extracorporeal energy balance observed in earlier studies [4,[6][7][8][9]. Changes in NO synthetic capacity did not correlate with changes in blood pressure in the present study.…”

“…All the latter procedures are associated with a significant energy loss over the extracorporeal circuit [4,7,9,10]. The second explanation for the impaired vascular response during hemodialysis is the 'nitric oxide' hypothesis, which proposes that vascular reactivity is impaired by an elevation of nitric oxide (NO) synthesis during the dialysis treatment [11][12][13][14]. Evidence for this hypothesis resides in the fact that NO levels increase during hemodialysis treatment and appear to be higher in those patients experiencing hypotensive episodes [15][16][17].…”

Comparison of Dialysis and Clinical Characteristics of Patients with Frequent and Occasional Hemodialysis-Associated Hypotension

“…Recently, increased production of vasodilator substances, the formation of nitric oxide in particular, has been implicated in the development of DH [23][24][25]. Our finding that the use of long-acting nitrates is associated with frequent DH brings up the intriguing question whether this may relate to the higher availability of nitric oxide during dialysis in these patients?…”

Hypotension Caused by Extracorporeal Circulation

“…30 It has indeed been reported that in cardiopulmonary bypass and hemodialysis, platelets are activated, 7,8 and the levels of both serotonin 3,7 and NO synthesis are increased. 9,10,31 The prevention of pump-induced hypotension by 5-HT 2B -receptor blockade in this study suggests that 5-HT 2 -receptor antagonists may be candidates for clinical use. The same might hold for inhibitors of NO-synthase, as suggested also by Peer et al, 32 or substances able to prevent shear-induced platelet aggregation.…”