Ketamine a Viable Choice for Adult Intubation

A new study concludes that ketamine, an intravenous (IV) induction agent, should be routinely considered for intubation in life-threatening situations in emergency departments (EDs).

Researchers at the University of British Columbia (UBC; Vancouver, Canada) completed a gray literature search of medical journals as well as the bibliographies of studies that compared the effect of ketamine with other IV sedatives for use in intubating patients. The data from the randomized controlled trials, as well as from prospective studies, were synthesized in a qualitative manner because the study designs, patient populations, reported outcomes, and follow-up periods were heterogeneous.

The authors found that ketamine did not adversely affect patient outcomes. No differences in neurological outcomes were found for patients who were sedated with ketamine, when compared with patients sedated with fentanyl, sufentanil, remifentanil, or etomidate. The results also showed that ketamine does not increase intracranial pressure (ICP), increase risk for death, or extend intensive care unit length of stay. The study was published online July 22, 2014, in Annals of Emergency Medicine.

“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,” said study coauthor Corinne Hohl, MD.

Ketamine is a rapidly acting dissociative agent that can provide analgesia, sedation, and amnesia for rapid sequence intubation in critically ill patients. A recent study, however, found that only 3% of ED intubations were performed with ketamine. The reluctance to use ketamine is based on case reports studies published more than 40 years ago that suggest ketamine increases ICP. Absence at that time of safety data, and the licensing of etomidate—another rapidly acting IV sedative agent—resulted in most emergency physicians opted to use etomidate for critically ill patients for whom traumatic or other neurologic injuries had not been ruled out.

However, in the past decade, important safety concerns about etomidate have reemerged because induction doses of the sedative have been linked with transient adrenal dysfunction, and intact adrenal function has been associated with improved mortality in critical illness. As a result, the use of ketamine in the management of undifferentiated critically ill patients has resurged, and with it, the debate over its potentially deleterious effects on neurologic outcomes.

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