Ketamine use in TBI – the ICP goes down not up.

H/T Rob Bryant for tweeting the paper.

[blackbirdpie url=”https://twitter.com/RobJBryant13/status/271116807195217920″]

We all love ketamine, or at least Minh does. But there has always been the bogey man stories, that if you use ketamine in someone with a head injury, there brain will explode and you’ll get covered in lots of brain goo which is never  a good luck. As a result, I rarely see people reach for ketamine as an induction agent for these people.

There is increasing evidence that the ICP rise attributed to ketamine is likely a bit of a myth based on faulty early data and even faultier interpretation (a bit like lignocaine/adrenaline is bad for fingers…)

This study provides a little bit more ammo that ketamine is safe for ICP. It’s not gold standard, bullet proof evidence but the case is building.

Bar-Joseph, Gad, Yoav Guilburd, Ada Tamir, and Joseph N Guilburd. “Effectiveness of Ketamine in Decreasing Intracranial Pressure in Children with Intracranial Hypertension..” Journal of Neurosurgery. Pediatrics 4, no. 1: 40–46. doi:10.3171/2009.1.PEDS08319. PMID 19569909

METHODS

• single centre in Israel in the PICU with kids with TBI
• two groups, 
  • one who got ketamine for a procedure
  • the other who got ketamine for the ICP specifically
• ketamine was 1-1.5mg/kg
• all were on midaz and morphine as sedation
• some had propofol as well
• a bunch got mannitol or hypertonic saline or thiopental and some even had decompressive craniectomy

RESULTS

• 30 patients, 82 episods of ketamine administration, most for treatment of raised ICP
• it worked, it lowered the ICP by about 5mmHg in both groups of patients

Their only concern is that some of the prior studies showed ICP rises in those who were probably inadequately anaesthetised. This bunch of kids were doped up to the max and they say maybe that’s why the ketamine is safer.

They were surprised that the ketmaine actually lowered the ICP not just didn’t increase it.

This is, of course, a tiny little study and with all the different interventions going on you could make the argument that we can’t tell if it was the ketamine that lowered the ICP. None the less it’s still encouraging that the bogey man of raised ICP is a little bit mythical.