Intraoperative Pulmonary Embolism

You are the duty anaesthetist in a small regional hospital and have been called urgently to assist the anaesthesia registrar in the emergency theatre. The registrar is anaesthetising a previously well 25-year-old man (75 kg, ASA I) who is undergoing open reduction and internal fixation of a fractured tibia and fibula sustained in a skiing accident two days ago. The registrar has noted progressive desaturation and increasing tachycardia over the last 15 minutes. The surgeons have deflated the tourniquet and are closing the wound.