Tolerance of large exchange volumes by peritoneal dialysis patients

Improving clearances on peritoneal dialysis involves either more exchanges, greater fill volume, or both. An increase in the number of exchanges is in convenient, resulting in noncompliance. Therefore, the best option is to in crease the exchange volumes; however, patients are often reluctant for fear of discomfort. We tested the tolerance of 20 patients blinded to randomly sequenced volumes of 2, 2.5, and 3 L, performed incenter by the dialysis nu rse. Each patient underwent one to three exchanges with each volume. At the end of a 4-hour dwell, the patient scored discomfort and estimated the inf used volume. Only one study exchange was performed each day; the rest of th e time, the patient continued his or her usual prescription. Fifteen of the patients (75%) were not able to identify the exchange volumes. Four of the five patients who determined the correct exchange volume for 67% to 78% of the exchanges (P < 0.04 compared with 33% expected by chance) had a body s urface area greater than 1.75 m(2). Of 123 exchanges, 84% were associated w ith no discomfort, 10% with mild discomfort, and 6% with moderate discomfor t. Patients were not more likely to have discomfort with 3-L compared with lower fill volumes. Peritoneal clearances of creatinine(6.1 v6.6 v7.7 mL/mi n/1.73 m(2)) and urea nitrogen (7.3 v8.6 v9.5 mL/min) were progressively gr eater with increasing exchange volumes (P < 0.001). We conclude that the ma jority of small as well as large patients will tolerate 2.5- and 3-L exchan ge volumes. If encouraged to do so, many patients could tolerate greater ex change volumes than they are presently using. Exchange volumes should be re adily increased as residual renal function declines. (C) 1999 by the Nation al Kidney Foundation, Inc.