Ketamine 2017 – 2 of 2

Don’t forget our next C & C next week on the 18th/July/17!

1500hrs~ @ Christchurch Operations Hub

This is the follow up blog for the Ketamine 2017 – 1 of 2 posted last week.

Just to review, historical, current and future use of Ketamine include;

  • Ketamine has been used in the operating room for nearly 50 years.
  • The bronchial dilatory profile of ketamine makes the induction and maintenance of anesthesia safer in patients with asthma and life-threatening acute bronchial constriction.
  • Cardiovascular characteristics, stimulating the central sympathetic system and inhibiting neuronal catecholamine uptake, ketamine is preferred in patients with unstable haemodynamics.
  • One of the very few drugs approved for anaesthesia induction in caesarean sections.
  • It is considered the agent of choice in children and burn victims
  • Ketamine is a special example of how an old drug can be readapted for new applications.
  • Ketamine has emerged as a promising drug for pain management, anti-depression and anti-inflammation (limited evidence).


Gao, M., Rejaei, D., & Liu, H. (2016). Ketamine use in current clinical practice. Acta Pharmacologica Sinica, 37(7), 865–872.


Ketamine for TBI

Let’s review another common topic of ketamine discussions by looking at our favourite LIFL re-Ketamine RSI for head injury.

Ketamine was traditionally “contraindicated” in patients with traumatic brain injury due to concerns about ketamine causing raised intracranial pressure.

  • Mostly derived from studies performed in the 1970s
  • Studies done on patients with non-traumatic intracranial lesions
  • Changes in ICP measured as changes in CSF pressure at lumbar spine and lateral ventricles with extrapolation to changes in CBF
  • Ketamine was shown to have deleterious increase in ICP predominantly in patients with obstructed CSF pathways

The bottom line is;

  • The evidence that ketamine elevates ICP is weak
  • There is no evidence that ketamine causes harm in TBI
  • Ketamine’s haemodynamic stability may be of benefit in the patient with traumatic brain injury requiring rapid sequence intubation


Low-dose ketamine infusion

Ketamine at doses greater 1 mg/kg has commonly been used as a dissociative anesthetic either to induce anesthesia, or for brief procedures in a perioperative setting. Low-dose ketamine, which is defined as a bolus dose of less than 0.3 mg/kg, may also be used to control perioperative, pediatric, chronic, or cancer-related pain as adjuvant analgesia (Lee & Lee, 2016).

Recent articles include;

Systematic review of the use of low-dose ketamine for analgesia in the emergency department

The Effects of Low-Dose Ketamine on Acute Pain in an Emergency Setting: A Systematic Review and Meta-Analysis

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

And this is an example of the low-dose ketamine administered as an infusion as part of the analgesic ladder.

PulmCrit- Reengineering the analgesic ladder for critically ill patients


Post ROSC and hypersalivation

Check out another SMACC talk by a Norwegian anesthetist, PHARM (Prehospital Air Retrieval Medicine) specialist physician.


Dr Per Bredmose, provides an in depth look at Ketamine in the prehospital setting. Per discusses the uses, benefits and potential complications of Ketamine, providing tips and tricks from his wealth of experience.

There are two take home points I’d come up with after listening to this podcast.

  1. Ketamine as a sedative agent post ROSC may not be a good idea, as it augments BP mainly via alpha adrenorecepters, but it causes SV reduction, and increases myocardial workload.
  2. Consider atropine for difficult airway to counter hypersalivation

NOTE: On the podcast, Dr Bredmose advise the use of Ketamine post ROSC to be withheld, however, Ketamine is the choice of drug for RSI or post intubation sedation for haemodynamically unstable patients under our CPG. The study also Dr Bredmose is referring to is a small study that concludes “ketamine should not be considered a first line drug for long-term sedation of patients with impaired left ventricular function.”


DANGER !!!– Ketamine Can Kill!

Lethal consequences of ketamine administration is well presented in the Minh’s great blog/podcast.

Death by Ketamine/Midazolam/ETOH combo.
“The myth goes that above a dissociative dose, any extra ketamine will cause only prolonged effect and no other adverse reactions. This is not true. Ketamine is a mild respiratory and cardiac depressant. The more you give, the more depressant effect.  It is certainly potentially lethal when given to alcohol intoxicated patients and extreme caution needs to be taken in this group (Cong, 2017).”

Haemodynamic stability myth busted!
Higher shock index ≥ 0.9 may also be associated with high rate (26% or 1 in every 4 patients) of hypotension (Miller et al., 2016).

* Shock index = HR/SBP = Example, HR 120, SBP 90 = 1.3

“Ketamine overdose is safe as it only results in prolonged effects”…really?

You may have heard about a case of a kid was given x100 dose but suffered no adverse effects apart from being sedated for longer. Nevertheless, only x10 dose caused this cardiac arrest….

Hospital mistake results in Cardiac Arrest: Part 1


Hospital mistake results in Cardiac Arrest: Part 2



While it takes a bit of courage, time and effort to have an online discussions, I’ve had some great feedback, discussions, and study materials etc sent to me more privately.
Please just engage in any way that you feel comfortable, and thanks for all your input!

See you next week at our C & C first anniversary for some ketamine related scenarios.




Beaudoin, F. L., Lin, C., Guan, W., & Merchant, R. C. (2014). Low-dose ketamine improves pain relief in patients receiving intravenous opioids  for acute pain in the emergency department: results of a randomized, double-blind, clinical trial. Academic Emergency Medicine : Official Journal of the Society for Academic Emergency Medicine, 21(11), 1193–1202.

Cong, M. L. (2017, February 4). PHARM Podcast 161 Can ketamine kill you? Retrieved May 8, 2017, from

Gao, M., Rejaei, D., & Liu, H. (2016). Ketamine use in current clinical practice. Acta Pharmacologica Sinica, 37(7), 865–872.

Melendez, E., & Bachur, R. (2009). Serious Adverse Events During Procedural Sedation With Ketamine. Pediatric Emergency Care, 25(5). Retrieved from

Miller, M., Kruit, N., Heldreich, C., Ware, S., Habig, K., Reid, C., & Burns, B. (2016). Hemodynamic Response After Rapid Sequence Induction With Ketamine in Out-of-Hospital Patients at Risk of Shock as Defined by the Shock Index. Annals of Emergency Medicine, 68(2), 181–188.e2.

Parsch, C. S., Boonstra, A., Teubner, D., Emmerton, W., McKenny, B., & Ellis, D. Y. (2017). Ketamine reduces the need for intubation in patients with acute severe mental illness and agitation requiring transport to definitive care: An observational study. Emergency Medicine Australasia: EMA.

Russell, K. W., Scaife, C. L., Weber, D. C., Windsor, J. S., Wheeler, A. R., Smith, W. R., … Lieberman, J. R. (2014). Wilderness Medical Society Practice Guidelines: Wilderness Medical Society Practice Guidelines for the Treatment of Acute Pain in Remote Environments: 2014 Update. Wilderness & Environmental Medicine, 25(Supplement), S96–S104.

Xu, Y., Hackett, M., Carter, G., Loo, C., Gálvez, V., Glozier, N., … Rodgers, A. (2016). Effects of Low-Dose and Very Low-Dose Ketamine among Patients with Major Depression: a Systematic Review and Meta-Analysis. International Journal of Neuropsychopharmacology, 19(4), pyv124-pyv124.

Zeiler, F. A., Teitelbaum, J., West, M., & Gillman, L. M. (2014). The Ketamine Effect on ICP in Traumatic Brain Injury. Neurocritical Care, 21(1), 163–173.



One Comment Add yours

  1. Andrew O says:

    A small write up in simple English to accompany it. Written for military context, relevant to anyone using it…


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