Hypotension on CAPD: An Approach to Treatment

Development of orthostatic hypotension occasionally complicates treatment of end-stage renal failure by continuous ambulatory peritoneal dialysis (CAPD). The cause may be excessive sodium removal via the dialysate relative to the dietary sodium intake, leading to the gradual development of sodium depletion. Therefore, a group of five symptomatic, hypotensive CAPD patients was treated with oral salt-loading without allowing a concomitant increase in body weight.

Supine blood pressure increased markedly after salt-loading (from 94/67 mmHg to 121/78 mmHg) and symptomatic orthostatic hypotension disappeared. The mechanisms leading to the improvement after salt-loading were studied in three of these patients. The beneficial effect of salt-loading was related to two mechanisms:

1) an increase in extracellular fluid volume and presumably blood volume;

2) an increase in sympathetic tone, as assessed by plasma norepinephrine levels and the pressor responsiveness to norepinephrine