In 2014, Scheppke et al. retrospectively studied 52 agitated patients who were given 4mg/kg IM of Ketamine8. The average time to sedation was 2 minutes (yeah!).

However, 3/52 patients had significant respiratory depression with 2 of those 3 patients requiring intubation in the Emergency Department (ED). Should we be concerned? Maybe. On one hand, intubating is a high risk procedure and should make every medical director a little squeamish. However, those three respiratory depressed patients also received IV Midazolam to prevent an emergence reaction. As a result Scheppke et al. concluded that “Ketamine may be safely and effectively used by trained paramedics following a specific protocol.” A major limitation to this study is that the authors did not evaluate outcomes of these patients in the ED. However, so far so good for Ketamine in that 1) providers can provide it safetly and 2) it works pretty darn fast.

Earlier this year (2016), Cole et al. performed a prospective study in their urban/suburban midwest community that services approximately 1,000,000 citizens while transporting 70,000 patients a year [9]. To minimize bias from seasonal changes, this service provided 10 mg of Haldol intramuscularly (IM) for severely agitated patients (defined as an altered mental status score of 2 or 3) for the first 3 months of the year. Subsequently, the authors changed the sedation medication to Ketamine 5mg/kg IM for the next 6 months. Afterwards, in the final three months of the year, they switched the sedative medications back to Haldol. So what did they observe? A total of 146 patients were treated with a median time for sedation of 5 minutes compared to Haldol’s 17 minutes to sedation. It appears that time to sedation using Ketamine was much faster in making the scene safe for our providers...but at what cost?!?!

It turns out that the Ketamine cohort had more side effects with more patients vomiting, more patients suffering laryngospasm (5% compared to 0.3%), and more patients being intubated (an intubation rate of 39% in the Ketamine cohort compared to 4% in the Haldol cohort).

Now, before we jump to any drastic conclusions about airway compromise, let’s take a little deeper dive into these intubated patients of this study. First, there was no association with the dosage of Ketamine and intubation rates. Next, the reasons for intubating these patients were documented as “Not Protecting Airway NOS.” Cole et al hypothesized that perhaps receiving physicians may be uncomfortable receiving patients in this dissociated state or may have, “misapplied the axiom ‘intubation for a GCS of 8.’” Certainly, those of us who are Emergency Physicians (EP), have had drunk patients arrive in the ED with a Glasgow Coma Scale (GCS) less than 8 and let them sleep it off without even a nasal cannula. Perhaps, when Ketamine is involved, EPs can also take this into account. However, is it because the EP wasn’t used to dealing with patients in the K-hole or was it truly an airway issue where the EP had to secure a compromised airway? Honestly, we can’t say for sure, but it is something to think upon when considering this manuscript for Ketamine in your system.

Finally, Olives et al. recently published their findings on the use of Ketamine (5mg/kg IM) for severely agitated patients in the prehospital environment [10]. In this 2 year retrospective study, they studied a total of 135 patients who displayed “...active physical violence to himself/herself or others and usual chemical or physical restraints may not be appropriate or safely used.” Prehospital providers reported an initial improvement in agitation in 91.8% of ketamine treated agitated patients. Awesome news!