Absolute treatment criteria for reducing the access volume
of a high-flow access (HFA, access flow >2 L/min) are absent.
Previous studies suggested that a HFA may influence the systemic
circulation including blood pressure (BP) and heart rate (HR). The aim
of this study was to determine these parameters after access clamping in
hemodialysis patients undergoing flow-reducing access surgery.
Systolic BP (SBP), diastolic BP (DBP) and HR in HFA
patients undergoing flow-reducing surgery were measured intraoperatively
before and after access clamping. Data were compared to values obtained
in patients receiving surgery for severe hand ischemia due to an access
(HAIDI, hemodialysis access-induced distal ischemia).Results:
In 8 years, 34 patients underwent surgery for HFA (n=23)
or HAIDI (n=11). Preoperative access flows in HFA were larger compared
to HAIDI (3,026±147 vs 1,078±139 mL/min, respectively, p<0.001).
Temporary clamping (15 sec) caused a 12±2 mm Hg increase in SBP (111±6
to 123±6 mm Hg, p<0.05) and a 6±1 mm Hg rise in DBP (57±4 to 63±5 mm
Hg, p<0.05) in HFA patients. In contrast, SBP and DBP increases were
not significant in HAIDI patients (+6±3 and +2±2 mm Hg, respectively,
p=0.37). HR was modestly reduced in both groups following access
clamping (−3±1 beats/min). The relationship between access flow volume
and alterations in SBP best fitted a quadratic regression model,
suggesting cardiovascular exhaustion with progressively higher access
flows > 2-2.5 L/min.
HFA may influence systemic hemodynamics in some
hemodialysis patients. The findings of this study may contribute to a
tailored management of a high-flow fistula in this population.
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