Posted by Matthew Mac Partlin on Sunday, July 22, 2012

Ketamine seems to be one of those divisive drugs that some practicioners really love using (professionally of course), some seem to despise and some are put off by the scare stories that permeate the textbooks. The preservation of airway reflexes and comparative haemodynamic stability draws favour, while the age-associated emergence phenomenon, increase in ICP and incidence of laryngospasm draws fire.

From a practical point of view, it is appealing as it can be given IV, IM, IO and even IN (intranasal) and provides effective analgesia and dissociation that permits significant procedures such as intubation and amputation to be completed.

The analgesic dose is 0.2-1.0mg/kg as a bolus or as an infusion at 0.2mg/kg/hr. An anaesthetic induction bolus dose ranges from 0.5-2mg/kg and a maintenance infusion can be run at 1mg/kg/hr or repeat boluses can be given every 20 - 30 minutes titrating to clinical response.

Here are some good sources of information on the use of ketamine from some of the online-savvy critical care and pre-hospital masters. This is not everything that they have on ketamine use, just the topics that are most relevant for motor sports medicine and trauma practice.

Cliff Reid's Resus M.E.

Protean uses and effects of ketamine.

Intranasal ketamine

Ketamine and laryngospasm 1

Ketamine and laryngospasm 2

Sedation for TBI

Ketamine and emergence 

Minh Le Cong's P.H.A.R.M.

Ketamine and prehospital amputation

Ketamine + propofol for induction

Scott Weingart's EMCrit

Procedural sedation

More procedural sedation

Awake intubation


 Ben Williams
• a year ago

Ketamine +- Benzo ( usually Diazepam ) would have to be the most commonly used anaesthesia in the third world. In practice a great margin of safety. I think the reason it is not more widely used is the history of emergence phenomena. Personally I have used small amounts for oral surgery patients with great results and would be a huge fan. My recipe for short painful procedures for an adult is 2mg Midazolam + 20 mg Ketamine, intravenously. Wait 60 seconds and then manipulate or whatever. I like the Intra Nasal option and will certainly consider it in the field should the situation occur. Perhaps moving an injured rider to a stretcher, removing armour, reducing a dislocated shoulder.

 Matthew Mac Partlin Ben Williams
• a year ago

Hey Ben,

I first met Ketamine in Kenya, where the surgeon's assistant was administering it for appendicectomies, cholycystectomies and Caesarian sections. I've since met anaesthetists and ED physicians who work with agencies that spend time in developing countries running short term, high turn-over theatres where monitoring and equipment are basic and limited by what an be carried.

It's a really useful drug that has an unfairly hairy reputation, which if you are prepared for can be minimised, if not negated.