From the Research
Heparin infusion should be initiated 4-6 hours after cardiac catheterization, once hemostasis at the access site has been achieved, with an initial bolus of 60-80 units/kg (maximum 5,000 units) followed by a continuous infusion at 12-15 units/kg/hour, as this approach balances the need for anticoagulation with the risk of access site bleeding complications following the invasive procedure. The decision to initiate heparin infusion should be individualized based on the patient's bleeding risk, indication for anticoagulation, and access site status, as noted in various studies 1, 2. Before restarting, ensure the access site is stable without active bleeding, hematoma formation, or other complications. Dose adjustments should be based on aPTT monitoring targeting 1.5-2.5 times normal, as this range is associated with a lower risk of thrombotic complications without significantly increasing the risk of bleeding, as suggested by studies on thrombin formation and the effect of unfractionated heparin during pediatric cardiac catheterization 3. Early mobilization should be delayed until the heparin effect is established, and the access site should be monitored frequently for the first 24 hours after restarting anticoagulation.
Some studies have investigated the optimal dose of unfractionated heparin for preventing arterial thrombosis in children undergoing cardiac catheterization, but the evidence is limited and inconclusive 1, 2. However, the most recent and highest quality study on this topic, published in 2020, found that the confidence interval for the risk of arterial thrombotic events was compatible with benefits of either high or low unfractionated heparin dose regimens 1.
The prevalence of heparin-induced thrombocytopenia in patients undergoing cardiac catheterization is low, but it is essential to monitor platelet counts and adjust the heparin dose accordingly, as noted in a study published in 2006 4. Bedside monitoring of heparin therapy using activated clotting time or activated partial thromboplastin time can help guide dose adjustments and minimize the risk of bleeding complications, as suggested by a study published in 1994 5.
In summary, the initiation of heparin infusion after cardiac catheterization should be guided by the patient's individual risk factors, access site status, and the need for anticoagulation, with careful monitoring of aPTT and platelet counts to minimize the risk of bleeding and thrombotic complications.