Intraperitoneal pressure and hernias in children on peritoneal dialysis

Abdominal wall hernias have been increasingly recognized in patients on con tinuous ambulatory peritoneal dialysis (CAPD). They are also more frequent in children than in adults. The aim of this study was to determine the infl uence of intraperitoneal pressure (IPP) on the development of hernias in ch ildren on CAPD, and if there was a difference between IPP in children and a dults. We studied 14 children aged 11.2+/-3.2 years, body weight 31.1+/-9.4 kg, who had undergone CAPD for 16.2+/-14.4 months. Also, 10 adults were st udied, aged 48+/-18 years, body weight 62.4+/-13.9 kg, on the CAPD program for 35+/-27 months. The IPP was measured via a column of dialysate in the p eritoneal dialysis line, immediately before the drainage of the peritoneal cavity. The pressure was measured with the patients in the supine position, at the level of the umbilical cicatrix with the zero point located on the mean axillary line. IPP was measured at inspiration and at expiration, and the mean of these two measurements was calculated. The children were divide d in two groups : group 1 (n=7) without hernias and group 2 (n=7) with hern ias (5 umbilical and 2 inguinal). The IPP of all children was 9.5+/-2.9 cm H2O. The IPP was 8.1+/-2.6 and 10.9+/-2.6 cm H2O in groups I and 2, respect ively (P=0.003). The instilled volume for test was similar in both groups. The IPP of the adults was 13.8+/-2.8 cm H2O, which was significantly greate r than that of the children (P=0.001). In conclusion, hernia is a common co mplication in children on CAPD and its prevalence is affected by IPP. Other associated factors may be the presence of anatomically weak sites in the a bdominal wall of the children, since IPP is lower in children than in adult s.