Tunnelled central venous catheters yield a low incidence of septicaemia in interleukin-2-treated patients

A retrospective study on the incidence of catheter-related complications and catheter indwelling time (t(CI) during treatment with continuous interleukin-2 (IL-2) infusion in patients with metastatic renal cell cancer, who were equipped with tunnelled central venous catheters (CVC). A group of 72 patients were treated with IL-2-based immunotherapy. Two induction treatment cycles of 35 days each were used. Treatment consisted of IL-2 as a continuous intravenous infusion (c.i.v.) with lymphokine-activated killer cells and interferon α intramuscularly. A tunnelled CVC was inserted at the start of treatment and was kept in place for the duration of the therapy or until the occurrence of complications. Out of 72 CVC, 30 (42%) functioned uneventfully for a median t(CI) of 64 days. In another 12 clinically uncomplicated cases (16%), catheter tips were positive in routine culture after a median t(CI) of 33 days. In 18 patients (25%), CVC-related infections were noted, including 8 (11%) local tunnel infections and 10 (14%) septic episodes. These complications occurred at a median t(CI) of 28 and 20 days respectively. In 15 (83%) of these 18 catheter infections, Staphylococcus aureus was isolated, whereas in the remaining 3 (17%) Staphylococcus epidermidis was found. Subclavian vein thrombosis was noted in 12 (17%) CVC at a median t(CI) of 31 days; 5 (36%) of these were diagnosed in the first 14 patients. This prompted us to administer prophylactic heparin 15000 IU c.i.v. daily during IL-2 treatment. Thereafter the incidence of thrombosis dropped to 7 (12%) in the subsequent 58 CVC inserted (P = 0.03). In conclusion, in contrast to previous reports on the high incidence of CVC-related septicaemia and thrombosis, we observed a relatively low incidence of these complications, which we ascribe to the use of tunnelled catheters and prophylactic heparin.