Adequacy of fluid/sodium balance and blood pressure control.

Hypotension and orthostatic hypotension are frequently observed in CAPD patients. In the present paper the possible causes of these complications were reviewed, and the roles of sodium and water were pointed out. In addition, we reported our experience using different sodium concentrations in CAPD dialysis fluid. In 38 CAPD patients sodium concentration in the dialysate was changed from 132 to 137 mEq/L. At first, arterial blood pressure increased in 4 patients (10%), and they were switched to 132 mEq/L sodium. Of the other 34 patients, 3 required larger doses of antihypertensive agents, while 9 reduced the number and/or dose of antihypertensive drugs. Thirst, body weight, residual renal function, 24-hour ultrafiltration, and biochemical examinations did not change using 137 mEq/L sodium concentrations for 6 months. In the 21 patients who did not change their antihypertensive treatment, upright blood pressure tended to increase, but the difference was not statistically significant. In 3 hypotensive patients sodium concentration was increased to 142 mEq/L. Thirst increased in 2 of the 3, one observed a transient increase in 24-hour ultrafiltration, and none showed changes in plasma sodium level. One patient developed reversible hypertension, one became normotensive, and the third had no changes in blood pressure.