Ketamine for emergency anaesthesia at very high altitude (4243 m above sea-level).

A 22-year-old woman presenting with postpartum haemorrhagic shock at 4243 m altitude required anaesthesia to identify and treat the source of bleeding. Slow intravenous administration of ketamine (0.5 mg x kg(-1)) resulted in deep anaesthesia and apnoea requiring hand ventilation for 5 min. Haemodynamic stability was maintained throughout the procedure. Haemostasis was achieved following uterine packing and suture of a second-degree vaginal tear and small cervical tear. Confusion and visual hallucinations occurred upon awakening but recovery was otherwise uneventful. Ketamine can be used for emergency anaesthesia in a wilderness environment over 4000 m but it is probable that the benefits outweigh the risks only where life or limb are acutely threatened. Careful titration of the administered dose is strongly advised, particularly in patients where hypovolaemia and/or hypoxaemia are present. The availability of airway management equipment and the skills to use them may significantly reduce the risks associated with anaesthetic administration at very high altitude.