Measurement of hydrostatic intraperitoneal pressure: a necessary routine test in peritoneal dialysis

This paper summarizes our clinical studies on hydrostatic intraperitoneal pressure (IPP), showing the interest of this measurement in routine clinical practice. IPP can easily be measured routinely be a simple and safe method: the measure of the column of dialysate in the peritoneal dialysis (PD) line before drainage, with point 0 located on the midaxillary line. The normal value is 12 +/- 2 cm of water (cm H2O) with an intraperitoneal volume (IPV) of 2 L, with linear increases of 2.2 cm H2O for each additional liter. IPP must be measured to estimate the tolerance of IPV: the maximal permissible IPV is reached for an IPP of 18 cm H2O, squaring with a decrease of 20% in vital capacity and sometimes arising before clinical symptomatology. However, IPP measured at rest could not predict PD mechanical complications (hernias, dialysis leakages, hemorrhoids, etc.), which are more dependent on parietal previous history or predisposition. IPP is significantly higher during the first three days after peritoneal catheter implantation (17 +/- 3 cm H2O) than during the 12 following days (10 +/- 4 cm H2O). It is recommended to postpone the start of PD until after catheter implantation, and patients should remain supine for the first three days. On the other hand, IPP strongly reduces the overall ultrafiltration (UF) volume: an increase of 1 cm H2O in IPP caused a decrease of 70 mL in global UF after two hours. Therefore, IPP should be measured in diagnosis of losses of UF. However, UF loss during peritonitis is not due to an increase of IPP.