A prospective double-blind randomized trial of urokinase flushes to prevent bacteremia resulting from luminal colonization of subcutaneous central venous catheters. Prophylactic urokinase in the management of long-term venous access devices in children: a Children's Oncology Group study. What really affects the incidence of central venous catheter-related infections for short-term catheterization?
This study was undertaken to determine if central venous catheter (CVC)-related infection in children with cancer could be prevented by monthly flushing of the catheter with urokinase.
                Between August 1994 and July 1998, 103 patients with cancer were randomized at the time of subcutaneous CVC placement to receive monthly flushing of their catheters with either 5000 IU of urokinase-heparin or heparin alone. Patients subsequently had blood cultures taken from their CVCs during an episode of fever.
                Seventy-four of the 103 patients (72%) enrolled in the study received at least 6 catheter flushes: 40 with urokinase-heparin and 34 with heparin. The median number of flushes was 9.5 in the urokinase-heparin group and 10.2 in the heparin-only group (P = 0.62). There were 5 positive blood cultures in the urokinase-heparin group and seven in patients receiving heparin alone (P = 0.27). Staphylococcus epidermidis was isolated from the blood of 3 patients receiving urokinase-heparin and 6 in those receiving heparin alone (P = 0.17).
                Prophylactic monthly catheter flushes with 5000 IU urokinase did not significantly decrease the number of documented bacteremic events in children with cancer who have CVCs. Infection and thrombosis are serious complications of long-term vascular access devices in children undergoing chemotherapy. Since routine fibrinolytic therapy may decrease these complications, the purpose of this study was to compare the efficacy of an every-2-week administration of urokinase with standard heparin flushes in reducing the incidence of device-related infections and occlusions.
                This study was a prospective, randomized phase III multicenter trial conducted by the Children's Cancer Group, in which patients with implantable ports or tunneled catheters received either urokinase or heparin every 2 weeks for 12 months. Study end points were time to first occlusion or time to first device-related infection.
                Five hundred seventy-seven patients from 29 institutions were enrolled, of whom 51% had external catheters and 49% had ports. Urokinase administration resulted in fewer occlusive events than heparin (23% v 31%; P =.02), a longer time to first occlusive event (log-rank analysis, P =.006), and a 1.6-fold difference in the rate of occlusive events (Poisson regression, P =.003). Similar results were noted when comparing ports and tunneled catheters. The urokinase group also had a 1.4-fold difference in the rate of infection (Poisson regression, P =.05) and longer time to first infection (log-rank, P =.07), but the difference was significant only in tunneled catheters.
                Urokinase administration every 2 weeks significantly affects the rate of occlusive events in ports and tunneled catheters and of infectious events in external catheters compared with heparin administration. Central venous catheterization is one of the important sepsis reasons in surgical patients. In this randomized controlled study, the effect of the frequency and type of catheter site care, as well as age, coexisting malignancy or diabetes mellitus, total parenteral nutrition administration and antibiotics use, on central venous catheter infection was investigated. Seventy-two single-lumen polyurethane catheters were included. In group I (n: 33), a transparent occlusive dressing was applied to the insertion site and not removed for 7 days unless there were signs of local infection. In group II (n: 39), daily site care was done with povidone-iodine 10% solution and a new sterile gauze was applied. Chi-square, linear correlation and multiple regression tests were used for statistical analysis. Mean duration of catheters was 8 +/- 4 days. There was no catheter-related sepsis. Ten (13.9%) patients had positive catheter tip cultures of whom three had site infection as well. The incidence of site and tip infections were not significantly different in group I and II (p > 0.05). Site infection and age younger than 60 years significantly increased the rate of tip infection (p: 0.004 and p: 0.02 respectively). Total parenteral nutrition administration was associated with higher rate of tip infection (p: 0.06). Coexisting malignancy or diabetes mellitus, duration of catheter and antibiotics use did not have any significant effect on the rate of central venous catheter infections (p > 0.05). In conclusion, we observed that the frequency of insertion site care and the type of dressing applied to the site had no significant effect on the rate of CVC infection. Insertion site infection was the most significant factor increasing the incidence of catheter tip infection. The use of the CVC for total parenteral nutrition facilitated tip infection as well.
Three RCTs for only two types of interventions to prevent CVC-related infections in children with cancer have been identified. Flushing CVC with urokinase (with or without heparin) compared to heparin alone possibly leads to decrease in CAI rates. Changing catheter dressings every 15 days versus every 4 days does not lead to more premature catheter removals due to infection although data were insufficient to assess if catheter-related infection rates were changed.