Ketamine IV versus IM

18 Feb

Roback MG, Wathen JE, MacKenzie T, Bajaj L. A randomized, controlled trial of i.v. versus i.m. ketamine for sedation of pediatric patients receiving emergency department orthopedic procedures. Ann Emerg Med. 2006 Nov.;48(5):605–612. PMID 17052563

This is (apparently) the first prospective IV v IM trial of ketamine for sedation. I have never given it IM, though it was previously on the CEM guideline as IM 4mg/kg. They now recommend 1mg/kg IV or 2.5mg/kg IM.

Anyhow to the trial.


  • paeds childrens ED
  • sedation for fracture reduction
  • randomised but unblinded
  • 1mg/kg IV v 4mg/kg IM
  • everyone got glycopyrolate
  • tried to blind but gave up when it didn’t work


  • n = 208
  • missed a whole bunch of eligible pts and not clear why
  • 100 each group
  • everyone did great
  • there were a couple of minor desaturations in the IV group
  • 35% vomiting IM; 18% vomiting IV
  • IM had a much longer period of sedation 130 mins v 80 mins
  • had to stop the study at nursing request cause they could tell which was which because of the performance characteristics


There was a much higher rate of vomiting than most studies. It’s usually reported about 5-10%. Their numbers seem pretty high.

As always it’s good to see that this is a remarkably safe thing for us to do in the ED.

I imagine a 35% vomiting rate wouldn’t be the most acceptable if you were an a gas man/woman working in an OT setting but in the ED we’re trying to balance all kinds of spinning plates and safety and ease are pretty important factors.

I think I’ll stick to giving IV ketamine for now.

4 Replies to “Ketamine IV versus IM

  1. Hey Andy… Importantly, the emesis is almost universally on emergence/waking rather than while sedated. Thus it is not dangerous per se, just unpleasant for all concerned. Their vomiting rate does seem excessive. Nowhere near that high in my experience.
    I must say, I decide IV or IM based on the type of sedation I need. If I think it might need redosing I go IV, if quick in and out and inserting an IV just seems like a palaver, I go IM. Although the stated sedation times are always around about the figures you give, this is not all useful sedation time – kids start doing funny starting stuff and moving around way before that, and I always find the panicky looks of parents when they think their kid is waking up a bit unsettling, so I like to be done way before this happens!

    • Agree on the emesis post sedation thing. That really shouldn’t put us off. It’s just that if a drug really has a 40% vomiting rate (and I don’t think it does) then it mightn’t be the best of “sedation packages”

      My experience is in the 10s not 100s so I’m no expert but the movement aren’t usually too much of a problem. Maybe for a facial lac repair but not for a fracture reduction.

      • As you suggest, it is the lac repair which I tend to go IV for so i can keep giving little aliquots if necessary. I must say I use 4 per kg if I go IM – I suspect their 2.5 dose is bit light on in some kids (although perhaps I am just impatient). I reckon emesis rate post procedure runs at about 5-10%, which is less than with nitrous through a 70:30 blender in my experience.

  2. Pingback: R&R In The FASTLANE 012 • LITFL • Research and Reviews

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.