PNEUMOPERITONEUM IN PERITONEAL-DIALYSIS PATIENTS

There has been recent controversy regarding the clinical significance of pneumoperitoneum in patients undergoing peritoneal dialysis. The in cidence of pneumoperitoneum has been estimated to be 21.2% to 33.7% in prior studies of peritoneal dialysis patients. Of the peritoneal dial ysis patients with pneumoperitoneum, only a small percentage (5.9% to 14.3%) had documented visceral perforations. The controversy arises in that anywhere from 20% to 100% of peritoneal dialysis patients with p neumoperitoneum and peritonitis had visceral perforation, and 32.4% to 57.1% of chronic ambulatory peritoneal dialysis patients had asymptom atic pneumoperitoneum of unknown etiology. These disparate incidences made clinical interpretation of pneumoperitoneum difficult. In additio n, prior study result disagreed as to the usefulness of the extent of pneumoperitoneum in predicting visceral perforation. We retrospectivel y reviewed 694 chest x-ray film and acute abdominal series reports fro m 1982 to 1993 in 75 peritoneal dialysis patients, with 9.3 +/- 1.3 (m ean +/- SEM) x-ray films per patient. The reports were confirmed by re viewing 363 x-ray films (52%). Eight patients (10.7%) had 10 episodes of pneumoperitoneum. Six of these eight patients had asymptomatic pneu moperitoneum from a known etiology: four had undergone abdominal surge ry for catheter placement the prior week and two had catheter manipula tion immediately preceding the xray. One patient had three episodes of pneumoperitoneum: one after catheter placement and two not associated with a known etiology for pneumoperitoneum while on the cycler. One p atient had a surgically confirmed colonic perforation with a large pne umoperitoneum and peritonitis. The patients with asymptomatic, nonpost operative pneumoperitoneum had small amounts of subdiaphragmatic air. We conclude that in peritoneal dialysis patients, the overall incidenc e of pneumoperitoneum and the incidence of asymptomatic pneumoperitone um of unknown etiology are variable and depend to a large extent on th e patient's technical competence in performing exchanges. However, pne umoperitoneum with peritonitis requires aggressive evaluation for visc eral perforation. This is a US government work. There are no restricti ons on its use.