Why is Ketamine a must in the prehospital setting...
Ketamine Links below...
When used correctly this medication has huge benefits.
Ketamine Pharmacology and Dosing
Ketamine is a NMDA blocker and is able to provide a wide range of therapeutic effects. It also competes with opioid receptors and catecholamine receptors (inotropic and chronotropic effects).
Those who don't know what NMDA stands for: N-Methyld-D-asparatate receptor and is essentially a neurotransmitter and memory component.
Ketamine is metabolized in the liver.
Onset is very quick with IM 2-10 minutes- typical effects are witnessed at 2-3 minutes.
IV doses should be pushed slowly and/or accompanied by a benzo, preferably Versed.
All of Ketamine's abilities are not fully understood, however because it has very sympathomimetic properties and its dissociative properties allow many various uses.
Many anesthesia groups will try to simplify its properties to "a hallucenagenitc like propofol. " Don't fall into this idea. Ketamine has very potent sympathetic interactions while propofol has a parasympathetic dominance. Even though both target similar receptors, they do not have the same action mechanism. Ironically some anesthesia departments use the two together as Ketafol, an entirely different conversation at a different time.
"However, this shared belief is not referenced in the American College of Emergency Physicians’ guidelines for ketamine use in the ED, for instance, so it is not actually true. In fact, this misguided principle is based on data from the 1960s and 1970s that has been quoted for decades. - See more at: http://www.pharmacytimes.com/contributor/craig-cocchio-pharmd/2015/09/is-ketamine-really-sympathomimetic#sthash.WBSliuzu.dpuf"
Doses, tricks and critical concepts.
For agitation, violent, or delirium patients, it is widely accepted that IM doses should be 4-5mg/kg with many services selecting a standard 5mg/kg dose.
IV doses are much different. We see many places utilize 0.1-0.25-0.5 mg/kg for pain management. We also see many utilizing 1.5-2 mg/kg for RSI or procedural sedation.
Sick patients or Septic patients should have considerations on dosing.
It is expected that 12% of patients with have hallucinations or an emergence reaction - it is in good practice to sedate the patient with a benzo after initial sedation typically before they wake or stir. I will say I often give a milligram or 2 of versed just as they start to move out of sedation. Or when sedating for RSI, once they are under I will follow with more ketamine or benzo's. I try to never allow a patient to wake from sedation for RSI, without consulting an MD or recievining facility.
In the USA Ketamine is a Pregnancy Class C drug. However it still recognized in some circles as a class X. It should be noted that other countries and some current studies are re-analizing the effects in pregnant women. It is always best to consult an MD for use of any medication in pregnant women.
One of the best educational podcasts on ketamine I have used over and over again credit to flightbridgeed.com