Cardiovascularcommon
A 71-year-old man receiving an unfractionated heparin infusion for a recent pulmonary embolus develops recurrent haematemesis and hypotension. The infusion is stopped; his activated partial thromboplastin time is 112 seconds (24–36 seconds), and the last heparin dose was given 90 minutes ago. Endoscopy is being organised, but bleeding continues despite transfusion. Which one of the following is the most appropriate specific reversal treatment?