Were you ever told not to give Ketamine to your head injury patients, hypertensive patients, increased intracranial pressure (ICP) patients? I was taught that. “Early studies suggested that ketamine could increase intracranial pressure, decreasing cerebral perfusion pressure and thereby reducing oxygen supply to the damaged cerebral cortex.” (NIH, 2022).

There have been 11 recent studies that were researching the effects of Ketamine in patients with an acute head injury. Nine of those studies showed no increase in ICP, blood pressure, or negative neurological effects. Two of the studies showed a limited increase in ICP, but still no negative neurological effects.

There was a recent study done studying the effects of Ketamine use on severe traumatic brain injuries in children. The study tested Ketamine on 33 children, aged 1 month to 16 years old. None of the children had an increase in ICP, but moreover, 11 children had a decrease in ICP after receiving Ketamine. (Boerner, 2023). Studying the effects of Ketamine on only 33 children is not a large enough study to 100 perfect change our protocols regarding Ketamine in head injuries, but these results were substantial enough to warrant a larger study, which is currently underway. “This study alone represents a near complete reversal in how we think about the relationship between ketamine and intracranial pressure. The results will likely lead to further studies that I believe will change 20 years of past thinking”. (Boerner, 2023).

There was another study done in 1997, after there was a carefully monitored experiment in giving three different doses of Ketamine to patients who already had an increased ICP due to a brain injury. These patients had invasive hemodynamic monitoring in place, they had labs drawn before and after each dose, and they had EEG brain monitoring. The study showed that every patient had a decrease in ICP, and improved labs after every dose.

Even with all these studies showing positive results in giving Ketamine to increased ICP patients, it is still not routinely done simply because data from more than 30 years ago said it could increase intracranial pressure and decrease cerebral perfusion. This is not the first time that a study with inaccurate information has negatively affected how we treat patients in the pre-hospital and hospital setting, and I’m sure it won’t be the last. This is just one example of why it is important for us to be open to change in the medical profession. As we gather reliable information, we need to be willing to change our mindset, and possibly our patient treatment. Just because “we’ve always done it this way”, doesn’t mean that we were doing the right thing, or we should continue to do things that way. Just like with all medications, you cannot completely predict how your patient will respond to Ketamine, regardless of if they have a head injury, increased ICP, or some other issue. Make sure you are following your protocols, doing continuous patient assessments and be aware of possible side effects or adverse reactions.

References:

Boerner, C. (April 4, 2023). Study shows ketamine could be beneficial for treating brain injury in children. VUMC News. https://news.vumc.org/2023/04/04/study-shows-ketamine-could-be-beneficial-for-treating-brain-injury-in-children/

NIH. (March 10, 2022). Ketamine in Acute Brain Injury: Current Opinion Following Cerebral Circulation and Electrical Activity. NIH: National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8949520/