Ultrasonography of the catheter tunnel in peritoneal dialysis patients: What are the indications?

The importance of sonography for the early detection and follow-up of tunne l infections in peritoneal dialysis patients is well documented, whereas ot her indications are less clear. We investigated indications and outcome of 738 ultrasound examinations of the peritoneal dialysis catheter tunnel. Ind ications for tunnel sonography included routine screening (27%), exit-site infection without peritonitis (24.1%), follow-up of tunnel infection (29.5% ), clarification of questionable results (7.5%), pain in the course of the catheter tunnel (1.8%), peritonitis without (5.3%) and with (2.0%) exit-sit e infection, search for foci (2.2%), and recurrent peritonitis (0.7%), No p ositive sonographic results were obtained during routine screening or in pa tients with fever or elevated C reactive protein levels showing no clinical signs of exit-site infection. Sonographic examinations were positive in 1 of 13 patients with pain in the course of the catheter tunnel, in 1 of 39 c ases of peritonitis not associated with exit-site infection, in 12 of 15 pa tients with peritonitis and simultaneous exit-site infection, and in 2 of 5 patients with recurrent peritonitis. Questionable results were detected in 15 of 178 patients with exit-site infection, in 15 of 199 routine examinat ions, in 2 of 16 examinations of patients with elevated C-reactive protein levels or fever, and in 2 of 15 cases of peritonitis and simultaneous exit- site infection. All but two of these questionable results had to be rated a s negative during further follow-up. We conclude that tunnel sonography is indicated in patients with exit-site infection (including cases with simult aneous peritonitis), for follow-up of tunnel infections, and for estimating the prognosis of these infections. Furthermore, tunnel sonography should b e performed in patients with recurrent peritonitis. Tunnel sonography is no t indicated for routine screening, search for foci, in cases of peritonitis without exit-site infection, or in patients with pain in the course of the catheter tunnel showing no other clinical signs of exit site infection, (C ) 1999 by the National Kidney Foundation, Inc.