There is not much evidence on the determination of peritoneal cavity size. But one would expect that the size of peritoneal cavity is directly proportional to the body surface area. Hence, ‘larger’ patients should receive increased fill volume (for example 3L).
In a small but nice study by Sarkar and colleagues (AJKD 1999;33:1136-1141), 20 PD patients received 2L, 2.5L and 3L fill volumes. At 75% occasions, patients were unable to correctly identify the fill volume. Furthermore, on 84% occasions there was no discomfort. Thus majority of PD patients can tolerate 2.5 to 3L fill volumes.
Increasing fill volumes also increase intra-abdominal pressure, which may lead to mechanical complications. Hence, we recommend that the fill volume should be increased in small increments and use lower % dextrose at higher volumes. A word of caution, patients should be assessed for the risk factors of hernia and other mechanical complications; and monitored regularly when using higher fill volumes.