Ultrasound evaluation of peritoneal catheter tunnel in catheter related infections in CAPD.

In cases of peritonitis and exit site infections it is important to determine the extent of involvement of the subcutaneous catheter tract. The assessment of such involvement by physical examination alone appears to be inadequate and insensitive. We examined the usefulness of ultrasound (US) examination of the catheter tract in delineating catheter related infections, and their relationship to each other and to peritonitis. Patients were examined during clinically defined states of exit-site infection (ESI), clinically defined tunnel infection (TI), peritonitis and in the normal condition. US examinations of the catheter tunnel were performed in 44 CAPD patients. A total of 47 US examinations (examination was repeated in three patients) were performed, divided among 13 episodes of peritonitis, four ESI, and 30 controls. In 12 of 47 US examinations, US-defined TI was demonstrated as a sonolucent pericatheteric fluid collection. These 12 positive US were distributed among seven patients with peritonitis, three with exit-site infections and two control patients. We conclude that peritonitis and ESIs are frequently accompanied by involvement of the catheter tract. It seems that both the internal and external cuffs do not constitute an effective barrier against the spread of infection.