Avoiding Night‐time Fluid Retention in CAPD Patients

with CAPD 4-6 hrs To the Editor: For many continuous ambulatory peritoneal dialysis patients, the long night-time exchange presents many disadvantages: (a) the retention of fluid in patients with decreased ultrafiltration capacity necessitates a greater use of hypertonic glucose solution during the day, which in turn leads to an increased glucose intake, hyperinsulinemia, obesity, and malnutrition (1-7). The use of hypertonic glucose solution also causes a greater loss of protein in the dialysate (8, 9). (6) Patients with a high peritoneal transport rate may also end up with decreased clearance of small and middle molecules during the long dwell exchange as a result of the reduction in drain volume (10, 1 1). These patients frequently have increased lymphatic absorption, further contributing to a decrease in solute clearance ( 12, 1 3) . In patients who have loss of ultrafiltration capacity and are high transporters, reducing the 8to 9-hour exchange during the night to a 4-hour exchange will probably not interfere with the quality of dialysis, as there will be a better clearance of small and middle molecules. By programming their alarm clock to ring at approximately 3:OO or 4:OO a.m., they could wake up, open the clamp, and allow their abdomen to empty, improving night-time clearances and fluid balance, Interference with sleep is a major disadvantage to such an approach. We would like to suggest a simple device to shorten the long night-time dwell without awakening the patient. The use of a dialysis bag with a long tube connected to the patient and a timer-clock clamp could allow the peritoneal dialysis fluid to automatically empty (Fig. 1). This approach would change the 8to 9-hour night-time exchange to a 4-hour dwell with all its advantages and without significant inconvenience (Fig. 2). mn