In this scenario, the finding that should indicate to the nurse that therapy is effective for a client with a pulmonary embolism is Option B: PaO2 75.
Pulmonary embolism is a condition where a blood clot obstructs the pulmonary arteries, affecting blood flow to the lungs. In this case, the initial treatment includes providing supplemental oxygen, administering IV heparin to prevent further clotting, and promoting bed rest to reduce the risk of dislodging the clot.
Monitoring the client's oxygenation status is crucial in evaluating the effectiveness of therapy. PaO2 refers to the partial pressure of oxygen in arterial blood, and a value of 75 indicates adequate oxygenation. This suggests that the therapy is effectively improving oxygenation and addressing the pulmonary embolism.
The other options mentioned (aPTT 70 seconds, CT scan of chest positive for infiltrate, calf edema and erythema resolved) are not direct indicators of the effectiveness of therapy for a pulmonary embolism. aPTT is a laboratory test used to monitor the therapeutic range of heparin, a CT scan positive for infiltrate may indicate other lung conditions, and resolution of calf edema and erythema may suggest improvement in peripheral circulation but does not directly reflect the effectiveness of pulmonary embolism therapy.
Remember, it is crucial to consult with the healthcare provider and continue monitoring the client's condition to ensure appropriate management and further interventions as necessary.