Target aPTT for Pulmonary Embolism with Acute Limb Ischemia

Dosing and Monitoring Protocol

For patients with pulmonary embolism and acute limb ischemia on unfractionated heparin (UFH), the target activated partial thromboplastin time (aPTT) should be 1.5-2.5 times the control value (45-75 seconds) 1, 2, 3, 4
The initial bolus dose of UFH should be 80 IU/kg intravenously, followed by a maintenance infusion of 18 IU/kg/hour 4
The first aPTT check should be 4-6 hours after the initial bolus, and after any dose change, the aPTT should be checked 6-10 hours later 4, 5
When in therapeutic range, daily aPTT monitoring is recommended 4, 5

Patients with pulmonary embolism complicated by acute limb ischemia require prompt and effective anticoagulation to prevent further thrombotic events 6
Supratherapeutic levels of anticoagulation increase bleeding risk, which is particularly concerning in patients with recent thrombolysis or surgical interventions 6

Heparin should be continued for at least 5 days and until INR is at least 2.0 before discontinuing 4, 5
Warfarin dose should be adjusted to maintain INR between 2.0-3.0 4, 5