Ketamine has been used by emergency departments for analgesia, sedation and amnesia for rapid, life-saving intubation in critically ill patients but decades-old studies suggested it raised intracranial pressure.

 A systematic review of 10 recent studies comparing ketamine to sufentanil, fentanyl and other pharmacological agents (vasopressors, neuromuscular blocking agents, sedatives) found no differences in intracranial and cerebral pressures of patients who had been treated with them.

Studies assessing patients sedated with ketamine found no difference in neurological outcomes compared to patients sedated with fentanyl, sufentanil, remifentanil or etomidate. Length of stay in the hospital was unaffected by ketamine use. Patients sedated and intubated with ketamine were also no likelier to die than patients sedated by other agents.

"Apprehension for many years about ketamine's effects on blood pressure or injured brains inhibited its use for intubation, especially in North America compared to Europe, but our review shows those concerns are likely overblown," said lead study author Corinne Hohl, MD, of the Department of Emergency Medicine at Vancouver General Hospital in Vancouver, Canada. "In view of recent concerns about the potential negative effects of an alternative induction agent, etomidate, ketamine should be considered routinely in patients with life-threatening infections and more regularly for patients who have been 'found down,' or unconscious, before being transported to the ER.

"Given the potential benefit to emergency patients and their physicians, the debate on ketamine should be settled by a large, randomized controlled trial. In the meantime, our review suggests what many emergency physicians already believe is true: Ketamine is safe and incredibly useful in critically ill patients who require rapid intubation."