A 59-year-old morbidly obese woman is admitted for cholecystectomy and postoperatively is placed on deep venous thrombosis (DVT) prophylaxis with mini-dose subcutaneous heparin. On hospital day 2, a peripherally inserted central venous catheter is placed in the right arm. The patient is discharged to a rehabilitation facility on hospital day 5 after removal of the venous catheter. Two days later she presents to the emergency room with right upper extremity pain and swelling. She reports she has not felt well enough to participate with physical therapy since being discharged from the hospital.
Venous duplex of the right arm demonstrates acute thrombosis of the right cephalic vein. Complete blood count (CBC) and chemistries are within normal range with a platelet count of 180 K/μL.
What should the target activated partial thromboplastin time (aPTT) be to achieve optimal efficacy and safety if anticoagulation with a DTI were to be initiated in this patient?
A. An aPTT of 3.0 to 4.0 times the baseline valueAn aPTT prolongation of 1.5 to 2.0 times the baseline value. Although the recommended range for therapeutic anticoagulation for VTE with a DTI is 1.5 to 2.5 times the baseline, which is not given as an option, published data indicate that anticoagulation with a DTI target aPTT of 1.5 to 2.0 times the baseline is just as efficacious and is associated with less bleeding risk.
Reference:
Warkentin TE, Greinacher A. Heparin-induced thrombocytopenia: recognition, treatment, and prevention: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest. 2004;126;311–337.