A patient’s central line appears occluded. Which method does the nurse use to determine if the catheter occlusion is internal?

The patient receiving bosentan therapy for pulmonary arterial hypertension presents to the emergency department (ED) complaining of dyspnea. Which nursing assessment is most important for this patient?

The patient newly diagnosed with idiopathic pulmonary arterial hypertension is prescribed bosentan. The result of which test is most important for the nurse to verify prior to administering the medication?