Thrombotic occlusion is a frequent complication associated with the use of
central venous catheters. The purpose of this study was to evaluate the efficacy of a continuous infusion of low-dose
urokinase (200 U/kg/h) in clearing
catheters that had not cleared after two bolus doses of
urokinase in a pediatric oncology population. Fifty-eight incidents of
catheter-related occlusions (49 Hickman-type
catheters/nine implantable ports) as documented by radiographic
dye study occurred in 227 pediatric oncology patients with 254
central venous catheters during a 1-year period. Fourteen of 58
catheters failed to clear after two bolus instillations of
urokinase (5,000 U and 10,000 U). Thirteen
catheters were treated for 24 hours with
urokinase, 200 U/kg/h, and one
catheter with
urokinase, 100 U/kg/h for 24 hours. Twelve
catheters were used for study. Coagulation studies were monitored preinfusion, 12 hours into the infusion, and postinfusion. Patency was reestablished in 11/12
catheters (92%) with a mean infusion time of 28.7 hours. No coagulation abnormalities or clinical
bleeding associated with the
urokinase infusion occurred. Only one patient exhibited a prolonged partial thromboplastin time (greater than 150 seconds); this was associated with a
heparin effect. These data indicate that low-dose
urokinase may be a safe and effective means to clear occluded
central venous catheters in children.