Intraperitoneal hydrostatic pressure and volume in peritoneal dialysis patients.

Dialysate Intraperitoneal Volume (IPV) represents one of the major determinants of Peritoneal Dialysis (PD) efficiency, but most adult patients are currently treated with the same standard IPV, regardless of body size. In order to evaluate the tolerability of different IPV, we adapted the current connection in use at our Institution to produce a simple method to directly measure Intraperitoneal Hydrostatic Pressure (IPP). We studied the relationship between IPV and IPP in 30 adult (age 19-77 years) patients (19 males) of various body sizes, on PD between 17 +/- 17 months. Mean end-inspiratory and end-expiratory IPP with different IPV were measured in each patient in the IPV range of clinical interest. A total of 210 individual measurements showed a statistically significant positive relationship between BSA-normalised IPV and IPP (r = 0.355, p < 0.001). Interpatient variability was high, thus suggesting that individualization of IPV according to body size is not accurate, IPP being often higher in larger body size. Direct IPP measurement with different IPV in the single patient is a simple, safe and reproducible procedure, allowing an individually tailored IPV prescription which should optimise PD efficiency while monitoring for IPP related complications.