The effect of acetate and bicarbonate dialysis on orthostatic blood pressure regulation

Dialysis-induced hypotension is probably due to multiple factors which reduce cardiac output and peripheral vascular resistance. That acetate, used in dialysate as a source of bicarbonate, may be one of these factors is suggested from several studies which show improved blood pressure regulation with bicarbonate-containing dialysate. We have further examined this hypothesis by comparing supine and standing blood pressure changes in nine stable patients during dialysis with acetate or bicarbonate solutions. Although mean weight changes were not different, standing blood pressure was lower after acetate dialysis. Such a hypotensive effect of acetate could result from depression of the force of myocardial contraction and/or from a reduction in peripheral vascular resistance.