Back in 2015, Dr. Sergey Motov’s (@painfreeED) group published a study demonstrating the efficacy of low-dose ketamine compared to morphine for analgesia in the ED. Here’s my quick analysis of that study as a UMEM pearl. The question, though, is how best to administer the 0.3 mg/kg IV ketamine dose while minimizing the risk of adverse effects.
Fortunately, Dr. Motov’s group has just published a follow-up study addressing that exact question.
What They Did
- Prospective, randomized, double-blind, double-dummy trial comparing safety and analgesic efficacy of IV low-dose ketamine given as a push dose (over 5 minutes) versus given as a short infusion mixed in 100 mL 0.9% sodium chloride (over 15 minutes)
- Pain scores, vital signs, and adverse effects were recorded at baseline, 5, 15, 30, 60, 90, and 120 minutes
- Overall rates and specific severity levels of side effects were recorded in accordance with the Side Effects Rating Scale for Dissociative Anesthetics (SERSDA)
- Patients < 46 kg or > 115 kg were excluded.
What They Found
- 24 patients were enrolled in each group
- At 5 min:
- Median severity of feeling of unreality was 3.0 on SERSDA scale for the IV push group versus 0.0 for the short infusion group (p = 0.001).
- Median sedation on RASS scale was greater in IV push group −2.0 versus 0.0 in short infusion group (p = 0.01).
- Decrease in mean pain scores from baseline to 15 min was similar across groups.
- No difference between groups for changes in vital signs or need for rescue medication.
Application to Clinical Practice
If you’re using low-dose ketamine for acute pain in the ED, or developing guidelines for its use, administer it in 100 mL over 15 minutes.
Note: A second study utilized this same approach with positive results (J Emerg Med 2017).
Motov S, Mai M, Pushkar I, et al. A prospective randomized, double-dummy trial comparing intravenous push dose of low dose ketamine to short infusion of low dose ketamine for treatment of moderate to severe pain in the emergency department. Am J Emerg Med. 2017 Mar 3. Epub ahead of print. PMID 28283340
The PharmERToxGuy 
Many of our providers have been turned off of ketamine for pain due to the adverse effects they see. This may open the door to more use. That being said, I’m curious if anyone has implemented this process. Given restrictions on controlled substance handling and USP 797 limitations for mixing non-emergent sterile products outside of an ISO Class 5 hood, I anticipate lots of delays having each dose mixed in pharmacy and delivered. Makes me wish I had a counter-top hood in the ED . . . Any suggestions?
LikeLike
We have approached this as an urgent medication that can be mixed in the ED. Understandably, some hospitals will not allow that. Alternatively, it could be administered via slow IV push (though this article argues against) or have it be prepared by the pharmacy with a 30-60 minute lag time from time to ordering to administration (not ideal).
LikeLike
How do you deal with the logistics of ketamine infusions? Our pharmacy says they will need 30-45 min to compound the ketamine, as they treat it like a Fentanyl drip.
LikeLike
We have approached this as an urgent medication that can be mixed in the ED. Understandably, some hospitals will not allow that. Alternatively, it could be administered via slow IV push (though this article argues against) or have it be prepared by the pharmacy with a 30-60 minute lag time from time to ordering to administration (not ideal).
LikeLike
Unfortunately we might have to go with slow IV push. I am trying to find some evidence to specifically show IV push ketamine is effective, but unfortunately all of the initial papers don’t specifically highlight how the ketamine was administered. Do you know of any papers that specifically highlighted slow IV push as the delivery mechanism?
LikeLike
Daniel, send me an email description of this issue to bryanhayes13@gmail.com. I’ll connect you with Sergey Motov, the author of several of the ketamine studies.
LikeLike
We are currently investigating our own process to possibly change to short infusion with the plan to approach it as an urgent med that will be compounded by ED pharmacist or nursing when ED pharmacist is not available in the department
LikeLike
Hi Brian
I know that they excluded patients over 115kg, but for patients who are considered “obese” would you use their actual body weight or ideal. I contacted Dr Motov and the max dose that they gave was 30mg (100kg patient). My institution is developing a guideline to use ketamine infusions for pain and a comment was brought up to use ideal body weight due to the kinetics ketamine.
thanks
LikeLike
Hi Mark, we follow the same max dosing as Sergey’s group.
LikeLike