For many patients with ESRF intravenous catheters are an essential route of vascular access for haemodialysis treatment. In the United Kingdom such patients constitute up to 17% of the dialysis population [1]. In this context rare infectious diseases may be encountered in the dialysis unit. We describe two previously unreported infectious complications of tunnelled dialysis catheters.
Case 1. A 57-year-old man presented with ESRF due to diabetes mellitus. His peripheral vasculature was unsuitable for the creation of an arterio-venous fistula (AVF) or implantable graft. A tunnelled dialysis catheter (Double-lumen PermCath) was inserted and haemodialysis commenced. Two months later he was admitted with pyrexia, rigors and a marked inflammatory response. He also complained of pain at the left sterno-clavicular joint. Repeated blood cultures, from separate sites, grew Staphylococcus epidermidis. Spiral CT scanning demonstrated evidence of osteomyelitis and clavicular destruction. The catheter was removed and peritoneal dialysis commenced. Antibiotic therapy with vancomycin and rifampicin was continued for a 6 week period with resolution of symptoms and inflammatory markers.
Case 2. A 62-year-old Yemeni man presented to our emergency department with ESRF. Owing to symptomatic uraemia a tunnelled catheter was inserted and dialysis commenced. Three months later the patient developed high fevers, with raised inflammatory markers. Repeated blood cultures were negative. Despite replacement of the line and empirical antibiotic therapy he developed a shallow 4 cm ulcer at the catheter exit site. The catheter was removed, and the ulcer biopsied. The culture grew fully sensitive Mycobacterium tuberculosis. Clinical and radiological assessment found no other sites of tuberculosis. After initiating treatment and replacing the catheter, the ulcer healed and the patient improved.
Discussion. Infection related to intravenous catheters remains a major source of morbidity and mortality in patients treated with chronic haemodialysis [2]. Osteomyelitis complicates up to 14% of these cases [3]. S. epidermidis is a common cause of bacteraemia in renal units [1]. In Case 1 we report sternoclavicular osteomyelitisa previously unreported but serious complication of what is considered to be a benign infection [4]. The incidence of M. tuberculosis has increased by 11% nationally (over 5 years) and by 71% in London (over 10 years) [5]. Chronic renal failure is known to cause immune dysregulation and is a risk factor for developing active TB. However, there are no reports of M. tuberculosis causing catheter exit site infection in this or other patient groups. Despite advances in renal replacement therapy there is no intervention proven to improve the immune status of dialysis patients or mitigate the infection risks associated with long-tem catheters. AVFs remain the gold standard for dialysis access due to improved patient survival [6]. With increasing use of tunnelled lines in immunocompromised subjects unusual infections are likely to be a growing phenomenon in dialysis units.
Conflict of interest statement. None declared.
1 Department of Renal Medicine Hammersmith Hospital Du Cane Road London, UK2 Department of Infectious Diseases Du Cane Road Hammersmith Hospital London, UK Email: shaunsummers{at}hotmail.com
References
|