Polite Dissent

Roger asked for some information on medically induced comas. As always, I’m happy to oblige:

When the brain is profoundly injured it begins to swell. There are many injuries that can lead to swelling including brain surgery, trauma, massive strokes, certain infections and certain toxins. This swelling and the resultant increase in intracranial pressure can injure the brain even more, leading to permanent brain damage or death.

Over the years, various methods have been used in an attempt to reduce the swelling of an injured brain. None of these techniques have been perfectly successful. Common procedures include hyperventilation, steroids, and medically-induced comas. In this last situation, the patient is kept unconscious by high doses of intravenous barbiturates. These drugs reduce the metabolic activity of the brain and decrease cerebral blood flow. This allows the swelling to go down, or at least, not progress as fast.

Medically induced comas have recently been used for Israeli Prime Minister Ariel Sharon after his stroke and surviving coal miner Randal McCloy for his carbon-monoxide injured brain. Jeanna Giese, the teen-aged girl who survived rabies, was treated in part with a medically-induced coma.

Medically induced comas are not a panacea for all brain injuries. They have a significant rate of side effects, most likely due to the high doses of barbiturates required. Cardiovascular depression is the most common side effect, though immune suppression and gastrointestinal problems are also common. There is also some controversy regarding how effective the comas are at preventing brain damage. They are generally a treatment of last resort when more conventional therapies have failed.

• This article provides information on medically induced comas that is easy to understand yet comprehensive.
• Yesterday, NPR interviewed a well-known neurologist on medically-induced comas. Listen to it here.