HACE – Effect of Barometric Pressure on the Pulmonary System

00:01 Now, a very serious form, this high altitude cerebral edema.

00:07 This can occur with things like confusion, ataxia, mood changes, hallucinations and even coma.

00:12 So you can imagine if you were a mountain climber, and if you were ataxic and hallucinating, your chances of making an error are much higher.

00:20 So high altitude cerebral edema can not only be life-threatening from an injury point of view, but also from the cerebral edema.

00:32 What are the causes of pathophysiology of high altitude cerebral edema? Well, it seems that the cerebral edema occurs because of an increase in blood flow.

00:40 As well as an increase in permeability of the blood-brain barrier.

00:44 What happens here is some of the substances move out of the blood vessels into the cerebral tissue and then swell that tissue.

00:55 And this example of this photograph is an autopsy where it can show this cerebral edema in some who had high altitude cerebral edema.

01:04 Normally, where you see these lines in this brain tissue, these should be deep sulci which means that they should be little valleys.

01:11 Here, they are flattened out.

01:17 Now how do you prevent and treat high altitude cerebral edema? Well, of course, prevention is always the best way and similar to acute mountain sickness, part of this involves gradual ascending to that new environment.

01:29 There is some pharmacology that sometimes can help.

01:32 Corticosteroids, which decrease inflammation, could be a benefit to decrease swelling.

01:40 But really, the most important thing is that any of these symptoms of high altitude cerebral edema are viewed, you need to get the person off of the mountain and so you need to descend them to a lower barometric pressure.

01:53 If that’s not possible, they’ve even come up with some specialized, what looks like a large sleeping bag in which you can pump up the pressure in the sleeping bag to create an artificial pressure environment.

02:04 And that type of environment can sometimes be enough to decrease the amount of high altitude cerebral edema.