Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Ketamine Myths Debunked in Four Podcasts


 

Many people are still afraid of using ketamine in EMS, because of various myths.

Dr. Minh Le Cong of PHARM – PreHospital And Retrieval Medicine has four excellent podcasts debunking the scare stories told by people unfamiliar with ketamine.

Go listen to all four podcasts about these ketamyths medical urban legends –
 

PHARM Podcast 75 Ketamine MythBusters Part 1 – Blowing your mind
 

Ketamyth 1 –
 

It has traditionally been avoided in the management of patients with traumatic brain injury owing to concerns that it may increase intracranial pressure.[1]

 

Does ketamine dangerously raise ICP (IntraCranial Pressure) for patients with head injuries?
 

Concerns regarding the potential for ketamine to raise ICP stem from small case control series several decades ago in patients with abnormal CSF flow dynamics [53].[1]

 

Medical myths are based largely on anecdote and unreasonable extrapolation, rather than evidence.

This myth assumes the effect should be generalized beyond the abnormal subset of patients in the study to all head injured patients and possibly to those in the room when ketamine is given to patients with head injuries.
 

[youtube]HY-03vYYAjA[/youtube]
 

Was the abnormal subset of patients in that study representative of the entire study?

No.

Does ketamine cause increased damage to patients with head injuries?
 

Several recent studies have refuted the original findings and showed no statistically significant rise in ICP in brain injured patients who are sedated with ketamine [56].[1]

 

But we should still avoid ketamine just to be safe, right?
 

The antagonism of NMDA receptors decreases the release of neurotoxic glutamate and may impart a protective effect in patients with traumatic brain injury [60].[1]

 

But we were told by experts that ketamine is dangerous.
 

Therefore ketamine is indicated particularly as an induction agent in patients with TBI and haemodynamic instability. It may have a role for refractory seizure activity.[1]

 

But some expert once said that there is a danger, so I am afraid the lawyers will get me, because I know less about medicine than lawyers do!!!11!!!
 

Based on its pharmacological properties, ketamine appears to be the perfect agent for the induction of head injured patients for intubation.[2]

 

We become dangerous when we base our decisions on politics, rumor, and bias, rather than valid evidence.

Go listen to the podcast.
 

And listen to the rest of the series of ketamine myth debunking –
 

Ketamyth 2 –
 

PHARM Podcast 76 Ketamine MythBusters Part 2 – Take the pressure down
 

Does it cause dangerous tachycardia and hypertension? How useful is it in the haemodynamically unstable patient?[3]

 

Go ahead. Bet that the myth is true. You know that your inner anecdotalist wants you to.
 

Ketamyth 3 –
 

PHARM Podcast 77 Ketamine MythBusters Part 3 – Are you mad enough?
 

Does it cause dangerous psychosis? How useful is it in the agitated patient? How common is the so called emergence delirium? What can you do if it happens? What can you do to prevent it from happening?[4]

Live dangerously. Bet on the myths. 😉
 

Ketamyth 4 –
 

PHARM Podcast 78 Ketamine MythBusters Part 4 – A fitting end?
 

Ketamine and epilepsy. Does it cause seizures? can it be used to manage seizures?[5]

 

For non-Commonwealth readers, who may be unfamiliar with the term fitting, fitting means having a seizure.
 

Ketamine has advantages over traditional antiseizure medications with less respiratory depression and hypotension[5]

 

We can rely on anecdote-based myths, or we can look at the actual evidence and learn the truth.
 

The great tragedy of Science — the slaying of a beautiful hypothesis by an ugly fact. – Thomas Henry Huxley.
 

Footnotes:

[1] Sedation in traumatic brain injury.
Flower O, Hellings S.
Emerg Med Int. 2012;2012:637171. doi: 10.1155/2012/637171. Epub 2012 Sep 20.
PMID: 23050154 [PubMed]

Free Full Text from PubMed Central.

[2] Myth: Ketamine should not be used as an induction agent for intubation in patients with head injury.
Filanovsky Y, Miller P, Kao J.
CJEM. 2010 Mar;12(2):154-7. Review. No abstract available.
PMID: 20219164 [PubMed – indexed for MEDLINE]

Free Full Text from CJEM.

[3] PHARM Podcast 76 Ketamine MythBusters Part 2 – Take the pressure down
PHARM – PreHospital And Retrieval Medicine
by rfdsdoc on July 20, 2013
Podcast page with links to evidence.

[4] PHARM Podcast 77 Ketamine MythBusters Part 3 – Are you mad enough?
PHARM – PreHospital And Retrieval Medicine
by rfdsdoc on July 31, 2013
Podcast page with links to evidence.

[5] PHARM Podcast 78 Ketamine MythBusters Part 4 – A fitting end?
PHARM – PreHospital And Retrieval Medicine
by rfdsdoc on August 14, 2013
Podcast page with links to evidence.

.

Comments

  1. I haven’t listened to the PHARM podcasts on the topic yet, but if you’re ever looking for even more thoughts on ketamine this is my favorite lecture. Lots of good pearls here: http://freeemergencytalks.net/2012/07/baruch-krauss-usa-2012-06-28-d2t2-1030-ketamine-in-the-emergency-department/