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

Choice A rationale An SpO2 of 97. Choice B rationale Low molecular weight heparin (LMWH), such as enoxaparin, primarily exerts its anticoagulant effect by inhibiting Factor Xa, and its effect is generally not monitored by the PTT (partial thromboplastin time). The PTT, which measures intrinsic and common pathway factors, is used to monitor unfractionated heparin. A value of 55 seconds is only slightly elevated from the normal range of 25 to 35 seconds but is not the standard monitoring parameter for LMWH. Choice C rationale A hematocrit of 45% falls within the normal range for an adult male (approximately 40% to 54%) and is a reassuring finding. Hematocrit is the percentage of red blood cells in the blood, and this normal value suggests the client does not have acute blood loss or significant anemia, which is a complication of anticoagulant therapy. Choice D rationale A decreased platelet count of 74,000/mm is a finding that must be reported immediately, as it indicates significant thrombocytopenia (normal range 150,000 to 450,000/mm). This could be due to Heparin-Induced Thrombocytopenia (HIT), a severe, immune-mediated adverse reaction to heparin (including LMWH) that paradoxically causes a high risk of life-threatening thrombosis and bleeding, necessitating immediate discontinuation.