Everyone loves ketamine. It’s a floor wax and a dessert topping. Traditionally, however, it has primarily been used in procedural sedation and the pre-hospital setting. In the Emergency Department, severe pain is almost universally the domain of intravenous opiates. Of course, opiates tend to disagree with some patients and cause others to be yet more disagreeable, so the search for alternatives continues.
This trial, similar to prior work, randomized severe, acute pain to an intravenous dose of 0.3 mg/kg of ketamine or 0.1 mg/kg of morphine. And, again, pain relief between two groups was statistically similar – and probably clinically similar, as well. The main difference, unsurprisingly, was adverse effects. The ketamine cohort was associated with an absolute surplus of 20% of patients complaining of dizziness, a surplus of 27% complaining of disorientation, and a few extra complaining of mood changes. However, all the extra adverse effects regressed to the level of the morphine group within 30 minutes.
We should be entirely settled by now regarding the safety and efficacy of ketamine. It works, and it works well – but some patients clearly find it unpleasant. I don’t foresee ketamine displacing opiates as typical first-line therapy for the majority, but there are certain types of patients and pain for which this would be a lovely option. If your hospital does not yet support its use for acute pain, they are falling behind and doing their patients a disservice.
“Intravenous Subdissociative-Dose Ketamine Versus Morphine for Analgesia in the Emergency Department: A Randomized Controlled Trial”
http://www.ncbi.nlm.nih.gov/pubmed/25817884
Ryan,
I like your take home comments. But I would emphasize a few key points.
It seems that more and more researchers are studying ketamine for pain relief in the ED. In many cases, I think the enthusiasm exceeds the science.
Almost all of the studies compare a fixed dose of ketamine to morphine or fentanyl. (This study used a good starting dose for morphine at 0.1mg/kg) But the reality is we should be titrating these medications to effect. It is not surprising that the studies show good effect compared to opiates when using starting doses or even "straw man" doses of them.
All of the studies confirm a troublesome side effect profile of subdissocative doses of ketamine. Sure it may have its place in those who we can't give opiates but please let’s stick with what we know works and is safe… adequate doses of narcotic pain medication.
Thanks for the comment, Brian.
I suppose what you're really getting at is – how many comparisons do we need between morphine and ketamine when no one is suggesting we replace opiates with ketamine? I'd be curious to hear if there is anyone truly pushing for ketamine monotherapy in the ED – any use I would have for it would as a secondary agent hoping for some sort of synergistic opiate-sparing effect. A more pragmatic design would allow for a "routine care" titration group compared with a combined therapy group – but you'd still have a hard time finding an outcome measure of value, considering opiates are nearly universally safe and effective.
We ARE looking for an alternative to narcotics! When the narcotic addiction rate is at the highest it's ever been and patients are using us as their obligated dealers and subsequent enablers, anything but narcotics needs to be considered and studied until it has been proven to be as good as the current standard, perhaps allowing the physician the freedom to choose. I embrace the concept of an opiate free ED and controlling pain from a multi-modal approach, rather than just slamming another opiate onboard. I am all for ketamine, and you can always slap a touch of ativan or even a kiss of benadryl at the time of administration and it is a smooth induction into pleasantville!
As a Combat Medic, I have to say, I would rather start a line and give Ketamine than Morphine. My reasoning is for that other side effect of Ketamine: The patient seems to forget about the whole ordeal. That's something that supersedes the reported headaches. It frees my bag of having to use narcan, I am free to monitor more patients and not worry about them going hypotensive and apnic. Morphine is great because it does work, but you can't free push morphine like you can ketamine!