A nurse is caring for a client who has fractured ribs, has developed thrombophlebitis, and is being treated with a heparin drip. The client develops hematuria and has an activated partial thromboplastin time (aPTT) of 100 seconds (60 to 80 seconds). Which of the following actions should the nurse take first?

A. Turn off the heparin drip: The client’s aPTT is significantly elevated and is accompanied by active bleeding, indicated by hematuria. Stopping the heparin infusion is the most immediate action because it removes the source of ongoing anticoagulation and helps prevent further bleeding. This stabilizes the situation before additional corrective measures are taken. B. Administer protamine sulfate: Protamine sulfate is the reversal agent for heparin and may be required, but it should be given after the heparin infusion is stopped. Administering it without stopping the drip allows continued anticoagulation, reducing the effectiveness of the reversal. The reversal medication is a secondary intervention. C. Repeat the aPTT now and in 1 hr: Rechecking coagulation labs is appropriate to monitor progress, but it does not address the immediate risk of ongoing bleeding. Delaying action while repeating labs can allow further anticoagulation and worsening hemorrhagic symptoms. Lab monitoring becomes relevant only after the heparin drip is stopped. D. Obtain a portable chest x-ray: A chest x-ray would not address the current problem of excessive anticoagulation and active bleeding. There is no indication of a thoracic complication requiring imaging at this moment, and performing this step would delay urgent action. The priority is to stop the heparin and control bleeding.