Factors Influencing ACT After Intravenous Bolus Administration of 100 IU/kg of Unfractionated Heparin During Cardiac Catheterization in Children.

Anticoagulation using intravenous bolus administration of unfractionated heparin (UFH) aims to prevent thromboembolic complications in children undergoing cardiac catheterization (CC). Optimal UFH dosage is needed to reduce bleeding complications. We analyzed the effect of bolus UFH on activated clotting time (ACT) in children undergoing CC focusing on age-dependent, anesthesia-related, or disease-related influencing factors. This retrospective single-center study of 183 pediatric patients receiving UFH during CC analyzed ACT measured at the end of CC. After bolus administration of 100 IU UFH/kg body weight, ACT values between 105 and 488 seconds were reached. Seventy-two percent were within target level of 160 to 240 seconds. Age-dependent differences were not obtained ( P = .407). The ACT values were lower due to hemodilution (total fluid and crystalloid administration during CC, both P < .001), with premedication of acetylsalicylic acid ( P = .014) and low-molecular-weight heparin ( P = .049). Arterial thrombosis (3.85%), venous thrombosis (0.55%), and bleeding (1.65%) following CC did not correlate with ACT values but occurred more frequently in children between 1 month and 1 year of age (91%). In conclusion, with a bolus of 100 IU UFH/kg, an ACT target level of 160 to 240 seconds can be achieved during CC in children in 72%, which is influenced by hemodilution and anticoagulant and antiplatelet premedication but not by age.