At what platelet count can I safely initiate long-term anticoagulation with warfarin (Coumadin) in cancer patients with thrombocytopenia and persistent atrial fibrillation (AF)?—EDGAR C. SALIRE, NP-C, Pearland, Tex.
The patient’s age affects the decision process as does the type, extent, and location of the cancer and whether it is metastatic. The hematologic function of the platelets needs to be determined. A patient can have an adequate number of platelets but still have platelet dysfunction (as seen in chronic renal failure). The thrombocytopenia needs to be established as stable, acute, or chronic. Generally, a platelet count >100,000/µL would warrant anticoagulation assuming normal platelet function. However, when the platelet count falls to between 50,000 and 100,000, the risks need to be carefully evaluated. There is always risk of stroke when a patient presents with AF. Before you decide to start anticoagulation therapy, obtain a CHADS [Congestive heart failure, Hypertension, Age >75 years, Diabetes, and previous Stroke] score. The CHADS score is a clinical prediction guideline that determines the level of anticoagulation therapy recommended. If warfarin (Coumadin) is warranted, the international normalized ratio may be targeted at different levels ranging from 2.0 to 3.0. The CHADS score is most beneficial for patients aged 65-95 years.—Debra Kleinschmidt, PhD, PA (138-3)