A nurse is reviewing laboratory data from a client who has pulmonary embolism and is receiving IV heparin. Which of the following findings should the nurse report to the provider?

The correct answer is A: Platelets 74,000/mm3. This finding should be reported because a low platelet count could indicate heparin-induced thrombocytopenia, a serious complication of heparin therapy. Platelets are crucial for clotting, and a low count increases the risk of bleeding.
B: White blood cell count within normal range, not directly related to heparin therapy.
C: PTT of 55 seconds is within the therapeutic range for heparin therapy.
D: Hematocrit of 45% is within normal limits and not a concern with heparin therapy.