DRUG-INDUCED COMA: Medically inducing a coma can help prevent permanent brain damage, in some cases.
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In the case of traumatic brain injury—such as the bullet wound sustained by U.S. Rep. Gabrielle Giffords in Saturday's assault outside a Tucson supermarket that killed six people and wounded 13 others—doctors sometimes induce a coma. This effective shutdown of brain function naturally occurs only in cases of extreme trauma, so why would doctors seek to mimic it in patients, as they have with the congresswoman, already suffering from head wounds and other issues?
The answer lies in the science behind general anesthesia, which some 60,000 patients undergo every day. A review paper in the December 30, 2010, issue of The New England Journal of Medicine reveals that such anesthesia is, essentially, a reversible coma.
That is exactly what doctors are aiming for in the case of a true medically induced coma, often using the same drugs or extreme hypothermia induced by exposure to a cold environment to halt blood flow entirely and permit surgery on the aorta. Shutting down function can give the brain time to heal without the body performing radical triage by shutting off blood flow to damaged sections. To find out more about such medically induced comas and the reasons why doctors employ them, Scientific American spoke with anesthesiologist Emery Brown of Harvard Medical School, co-author of the NEJM review.
[An edited transcript of the interview follows.]
What is a medically induced coma?
So basically what happens with a medically induced coma is that you take a drug and administer it until you see a certain pattern in the monitor that follows the patient's brain waves, the EEG [electroencephalogram]. Patients with brain injuries who are in a coma have a similar pattern. If that pattern is there, then you feel comfortable that the patient is in a drug-induced coma. You are doing it so that you can hopefully protect the brain.
What are you protecting the brain from?
If you've had a brain injury, what happens is the metabolism of the brain has been significantly altered. You may have areas without adequate blood flow. The idea is: "Let me reduce the amount of energy those different brain areas need." If I can do that then, as the brain heals and the swelling goes down, maybe those areas that were at risk can be protected.
But the main thing about a drug-induced coma, as opposed to a coma, is that it's reversible. If you do this to someone with a normal brain, they would come right out of it once you removed the drugs.
But it's used in the case of people with brain injuries. So what are the risks?
Speaking generally, the main effects that these drugs have outside the brain is they reduce blood pressure. So people trying to do this are giving a lot of other medicines to keep blood pressure up and keep the heart pumping in a nice way. You're protecting the brain on one hand and, on the other hand, all areas of the brain are not getting the blood they need necessarily.
If you do this for an extended period of time, the drugs can accumulate and it may take them a while to wash out of the system as well. As long as you're mindful of these things you can see someone through a period like this.
How long is that period?
It really depends on the injury, whether it's a brain injury or seizing. One patient was kept in [a drug-induced coma] for six months. Obviously, that's the tail end of the distribution.
It depends on how the person is progressing and the nature of the injury. What the neurologists or [intensive care unit] doctors do is try to have them come out as soon as possible. In a case like Gifford's they have swelling. If they see the swelling recede, then they may try to lighten up the coma to see if she can come back and see what her level of function is.
How safe are drug-induced comas?
A drug like propofol, we use this every day in the operating room. It is probably the most used drug in all of anesthesia. Every day essentially, when patients go under general anesthesia that whole state is a reversible coma. It's a difference in dosage.
How does a medically-induced coma differ from a natural coma?
The body doesn't usually decide to enter a coma. A coma is a profound shutdown of brain function. It typically results from profound trauma, brain injury, a drug overdose, stroke—some very gross insult. There isn't a natural analogue for [a medically induced coma].
Are there after effects?
It's hard to sort out, because if you're going to these extremes you're already dealing with a very dire situation. If there are effects later on, it's an extremely difficult distinction to make whether it is an effect of the drug-induced coma. People who do this are very mindful of watching and monitoring. They make every effort to only use this option for as long as they need to.
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12 Comments
Add CommentHibernating mammals that do reduce their body temperature, heart and respiratory rates, enter some kind of a natural, reversible coma, however, they must rewarm and speed up their whole system for a while during the sleeping season, apparently just for an equivalent of human dreaming, or REM sleep. There's still a lot of missing information on CNS
Reply | Report Abuse | Link to this30 months ago, Surgeons placed me in a coma for several days following mesenteric ischemia. My family reports that heroic measures, involving many machines and medications, kept me alive. One of those measures also involved a person present at my bedside every minute I was in the coma, "watching and monitoring." I was back at (limited) work in two months after the surgery. No, I don't remember anything that was said or done while I was in the coma.
Reply | Report Abuse | Link to thisCurious. I was in an induced coma for about a month due to a nasty Jeep roll over and sustained some massive trauma (broken back, broken neck, broken ribs, collapsed lung, ripped heart, shattered clavical, etc). Anyway, to make a long story short, what I "saw" in that coma was horrific to say the least. It was one ongoing nightmare that I couldn't awake from. That being said, it took me MUCH longer to heal from the imagery in that coma than it did from the physical injuries. Thankfully I'm back to 100% (well, not that much....let's say 98.9% to be more realistic). At that, I'm finding it nearly impossible to find anyone out there who has shared a similar experience akin to mine.
Reply | Report Abuse | Link to thisI was also in an induced coma for a month, barely surviving a viral infection in my heart. I too had a nightmare that seemed to last for forever. Having no sense of time, I don't really know how long. It was an endless series of terrible events, one situation leading to the next. My friends and I now joke about all the scenes I can recall. They're funny now, but very vivid then.
Reply | Report Abuse | Link to thisLast year I was hospitalized with double pneumonia. Since the treatment necessitated inserting a respirator, the medical staff placed me in a drug induced coma. This lasted for a bit over a month My experiences were quite similar to those related by both you & biconderopus above.
Reply | Report Abuse | Link to thisSince returning home (last August), I've noticed that certain words, names & some events that are somewhere in my memory bank are inaccessible on demand. After a few minutes, they invariably pop into my awareness.To date it has been just a minor inconvenience, but it's starting to bug the heck out of me!
Have you had similar experiences?
In late 2009, I was in a medically induced coma for five weeks as a result of the H1N1 virus which led to pneumonia, than ARDS. I had similar experiences to biconderopus, mitch3985, & TwoPlus Two with horrific nightmares that my mind identified as memories when I woke up. As I was paralyzed from the neck down and unable to speak due to my tracheotomy, it took me some time to realize what I had experienced were not actually real life events or memories.
Reply | Report Abuse | Link to thisI have also been experiencing the same inability to verbalize certain words, as described by TwoPlus Two. To say it is bothering me is an understatement!
Reply | Report Abuse | Link to thisIn July 2009 I was in induced coma due to H1N1 virus coupled with Legionnaire's Disease which led to my body going into Sceptic Shock.
Like many of you, I have also experienced nightmares that seemed unbelievably vivid and detailed. It took me a few days after I was woken up to realise that they are not real.
For a while I had no "live" memories of how I have ended up in hospital even though I was told.
Certain things people said around me while in coma also got incorporated into the nightmares but with some changes.
It was more difficult to get over the nightmares than to recover physically.
The Human Mind certainly is an amazing labyrinth.
Till this day I do have problem remembering names, words and also became a bit dyslexic when writing either by hand or on the keyboard. (thank goodness for spellcheck)
But I prefer being alive even with a slight memory loss than not being able to experience the joy of living anymore.
I guess the best thing to do is train our brain by doing brain teasers, playing memory games, doing crosswords, etc.
Wishing you all Health & Happiness :o)
About 3 months ago, I was put in an induced coma. I had pneumonia and had to have a respirator. It took several days to get over the halluciations I had. I was so sure it was all real, and it took a few weeks to snap out of the deep depression I was in. I also have trouble with words since this has happened.I am doing so much better now, and so glad I found this site. I don't feel so alone about all this now. May God bless all of you!
Reply | Report Abuse | Link to thisif there are any anesthesiologists/doctors reading this, can you please update us on what is being done to minimize the "nightmares"? From what I've read, some of these may be due to the drugs administered (maybe not enough to hinder "remembering" things while in the coma). And does anyone know the frequency of induced comas (any stats on this relative to performed surgeries)? seems like it is no longer used for just brain injury/trauma....
Reply | Report Abuse | Link to thisjust checking for updates...
Reply | Report Abuse | Link to thisI was put into a medically induced coma in late December 1998 and was under for about 3+ weeks. I had horrible nightmares the entire time I was under. I do not believe I rested at all. My brain was churning out terror after terror, all seemingly in real time. I think I flash back occasionally, triggered by something I will see or read. I used to joke about the holidays saying, "Just put me in coma until New Year." Ha ha.
Reply | Report Abuse | Link to thisIt's called ICU psychosis...it is a common phenom with some reports of 1 in 3
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