Heparin elimination following continuous infusion during intra‐aortic balloon counterpulsation

Abstract

The decline of the activated partial thromboplastin time (APTT) following discontinuation of heparin infusion was measured in six intra-aortic balloon pump (IABP) patients. The heparin infusion requirement was determined for eight other IABP patients during stable therapeutic anticoagulation. Following discontinuation of infusion, APTT declined with a relatively constant half-life (t 1/2 of 2.4 +/- 0.08 hr, suggesting elimination by first-order kinetics. In comparison, the t 1/2 following single bolus doses has been shown to be markedly dose dependent, increasing from 30 min at low doses to 2 hr at very high doses. The heparin requirement for IABP patients was found to be 16 +/- 2.5 U/kg/hr, similar to that reported for other clinical situations. The t 1/2 of the APTT following discontinuation of heparin infusion can be used to time invasive procedures that would best be done with normal hemostasis.

Comparison of Safety between Different Kinds of Heparins in Patients Receiving Intra-Aortic Balloon Counterpulsation

“… 3 To minimize the likelihood of catheter-related thrombosis and embolism, anticoagulant(s) must be used—typically with unfractionated heparin (UFH)—at an infusion rate that maintains the activated partial thromboplastin time (aPTT) within 50 to 70 seconds. 4 Low-molecular-weight heparin (LMWH, ∼4.5 kD) inhibits the Xa/IIa activity at a ratio of 1.5 to 4.0:1.0, as opposed to 1.0:1.0 for UFH. As a consequence, LMWH has lower antithrombotic ability and less impact on aPTT.…”