Prevention of umbilical artery catheter clots with heparinized infusates

49 neonates requiring umbilical artery catheters (UACs) were randomly assigned to receive standard or heparin-containing infusates. 3 of 23 (13%) of the patients receiving heparin had catheters removed because they became functionally occluded compared to 15 of 26 (58%) in the control group (p less than 0.005). 4 of 13 (31%) single injection aortograms obtained in control infants demonstrated thrombi, compared to none of 7 in the heparin group. 1 patient in the heparin group had an aortic clot demonstrated at post-mortum examination. There were neither clinical coagulopathies nor abnormalities of partial thromboplastin time attributable to the administration of heparinized fluids. Heparinization of UAC infusates appears to be a safe method of reducing the risk of catheter occlusion. Heparin effect on large vessel clot risk remains unproven.