Why your suicidal patient might benefit from ketamine – the latest evidence
Over the last month or so, there has been some blogging and podcasting on suicide risk assessment and the topic of suicidality on general. If you have not caught up with this then check it out!
Broomedocs Podcast 3 Suicide with Minh
Broomedocs podcast 10 Suicide assessment with Rob Orman
The US military have of late become more interested in research into rapid antidepressant and antisuicidal therapies due to increased suicides in soldiers in current service.
US army antisuicidal nasal spray
The challenging aspect of managing suicidality in the ED or primary cAre setting, is that we know many will contact us prior to any completed suicide attempt, so there is a window of opportunity to intervene. We know though that our main interventions are very limited and often take a long time to work i.e current antidepressant medications.
We say to ourselves, its not like sepsis management where there are proven interventions that we know that if given early, will improve outcomes rapidly, like IV antibiotics. The Surviving sepsis campaign has been well ingrained in our emergency care thinking!
But what if there was a Surviving Suicide campaign? What if there was an IV therapy that was rapidly effective against suicidal symptoms? What if the earlier you diagnosed and administered this therapy, lives could be saved? What if suicidal state was in fact an inflammatory state of the brain?
Well for those who follow my blog, you would know I have written on the antisuicide properties of ketamine before. This has been recognised increasingly in the last 5 years.
I have noticed this in my prehospital and retrieval experience, with suicidal patients who are agitated, not responding to benzodiazepines, antipsychotic agents like olanzapine, but some IV ketamine seems to resolve the agitation. Of course I assumed this was of the general anaesthetic properties of ketamine, but I noticed it would often take no more than sub anaesthetic doses of ketamine to be effective, 20-40mg IV boluses. It is my conclusion that I have been witnessing now a specific antisuicide quality of ketamine.
Many colleagues are skeptical of this observation as a proposed mechanism for why ketamine should have uniquely antisuicide property has been elusive…
In an advanced online publication that is open access in the Journal of Neuropsychopharmacology , January 2013, international researchers have measured inflammatory markers in the CSF of patients admitted with suicide attempt and found these interact with NMDA receptors. These inflammatory markers were elevated significantly during the acute suicidal state but declined at 6 month followup. Thats right, they repeated the lumbar puncture at 6 months. They propose that the ketamine rapid antisuicidal effect is due to its NMDA antagonistic effect, opposing the inflammatory stimulation of the NMDA receptors within the Brain.
Its not perfect RCT evidence but it is growing body of evidence that novel pathways of neurobiology in suicidal states may hold promise to developing NMDA active agents, and that a prehospital IV agent like ketamine may one day become the Surviving Suicide campaign early intervention!
Here is the full open access article. Read it!
Connecting inflammation with glutamate agonism in suicidality