Biomedical Engineering Blog

Biomedical Engineering

The Biomedical Engineering blog is the place for conversation and discussion about topics related to engineering principles of the medical field. Here, you'll find everything from discussions about emerging medical technologies to advances in medical research. The blog's owner, Chelsey H, is a graduate of Rensselaer Polytechnic Institute (RPI) with a degree in Biomedical Engineering.

Previous in Blog: The Science of Sports   Next in Blog: Airborne: A Cure for the Common Cold?
Close
Close
Close
9 comments

Cheating Death: Therapeutic Hypothermia

Posted November 27, 2007 12:01 AM by shanlax

What if you could save a life by subjecting someone to something that would normally cause a slow, painful death? Today, doctors are doing just that. Therapeutic hypothermia (induced hypothermia) is the intentional lowering of a patient's body temperature to a level below that which is required for proper metabolic functioning. So why are neurosurgeons and cardiologists using this chilly technique? Medical research indicates that therapeutic hypothermia can reduce brain damage and increase survivability after cardiac arrest.

Placing a patient in hypothermia slows down their heartbeat and delivers blood and oxygen to vital organs at a slower blood-flow rate. After cardiac arrest, doctors must restore cerebral circulation – but not too quickly. By reducing the body's metabolic activity, therapeutic hypothermia can minimize the chance of reperfusion injury, damage to tissue that can occur when the blood supply is restored too rapidly. Although wrapping a heart-attack patient in a blanket is a standard practice, warming the body could possibly worsen the effects of cardiac arrest on the brain.

Induced hypothermia lowers a patient's body temperate slowly and predictably, to around 91º F. That's almost 8º F less than the human body's normal temperature! Of course, special techniques must be followed. For example, a patient must be given a sedative to reduce shivering, a natural reaction to cold. Therapeutic hypothermia isn't a panacea, however. Infections and internal bleeding can still occur, but they are usually easier to correct than brain damage.

Although some doctors are reluctant to use therapeutic hypothermia, more hospitals and emergency rescue services are willing to give it a try after watching the survival numbers soar. Clifton Callaway, part of the Safar Center for Resuscitation Research at the University of Pittsburgh, says doctors should induce hypothermia whenever a heart-attack patient with a pulse arrives at an emergency room. In this way, doctors can know that a death from cardiac arrest is "not because of something we neglected to do."

"Sometimes, Callaway explains, "nature just holds all the cards. "But you don't want for it to be that you left cards on the table." So let's hold our cards and cheat death however we can. The jackpot you hit could save a life.

Resources:

http://www.usatoday.com/news/health/2006-12-10-body-cooling-cover_x.htm

http://www.americanheart.org/presenter.jhtml?identifier=3013397

http://circ.ahajournals.org/cgi/content/full/108/1/118

Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
United States - Member - New Member Technical Fields - Technical Writing - New Member Popular Science - Weaponology - Organizer Hobbies - Target Shooting - New Member Engineering Fields - Nuclear Engineering - New Member

Join Date: Mar 2005
Posts: 3464
Good Answers: 32
#1

Re: Cheating Death: Therapeutic Hypothermia

11/27/2007 9:46 AM

Great story, shanlax. NFL fans may remember how earlier this season, Kevin Everett of the Buffalo Bills nearly died from a spinal cord injury from a helmet-to-helmet hit. According to Dr. Barth Green, chairman of the department of neurological surgery at the University of Miami school of medicine, running an ice-cold saline solution through Everett's system significantly decreased the damage to his spinal cord from swelling and movement. "We've been doing a protocol on humans and having similar experiences for many months now," Green told ESPN back in September. "But this is the first time I'm aware of that the doctor was with the patient when he was injured and the hypothermia was started within minutes of the injury. We know the earlier it's started, the better."

Thanks to therapeutic hypothermia, Kevin Everett is alive and well and may walk again soon.

Reply
Guru
New Zealand - Member - Kiwi Popular Science - Weaponology - New Member Engineering Fields - Power Engineering - New Member Engineering Fields - Electrical Engineering - New Member

Join Date: Sep 2006
Location: Auckland, New Zealand
Posts: 8778
Good Answers: 376
#2

Re: Cheating Death: Therapeutic Hypothermia

11/27/2007 2:05 PM

As someone who has nearly died of hypothermia (and it's NOT painful at all) during one of my many tramping excursions I recommend to fellow trampers and hikers (especially those that like to do it alone) that they should experience it (under controlled conditions of course). It is a very, very bizarre feeling. Your brain starts to shut down and logic just goes out the window and people do incredibly strange things such as taking off their wet clothes and putting on their only spare set of dry clothes, when it is still pouring with rain! Even when I recognized the fact that I was in trouble I was physically unable to stop and put on more clothing to warm myself up (I knew I was in trouble but it was like I had no control, and strangely enough I was not feeling cold).

Having been thru this experience, I can now recognise the symptoms and take action in future. You can teach and warn someone all you want, but nothing beats actual experience (like electrocution, but that is another story ).

__________________
jack of all trades
Reply
Power-User
Fans of Old Computers - PDP 11 - New Member

Join Date: Mar 2007
Location: In a mushroom field somewhere in Canada. Kept in the dark and fed sh--, well you know.
Posts: 312
#3

Re: Cheating Death: Therapeutic Hypothermia

11/28/2007 7:46 AM

Jack:

There have been numerous experiments conducted here in Canada in the arctic on hypothermia. Most being done while buried under the snow and in the ocean under the ice. What you experienced is what the scientists found out is a basic survival instinct just as when your body shivers when you start to get cold.

__________________
Dirt is for vegetables. Pavement is for racing.
Reply
Active Contributor

Join Date: May 2007
Location: Washington, DC
Posts: 16
#4

Re: Cheating Death: Therapeutic Hypothermia

11/28/2007 8:34 AM

Wow Shanlax! What an interesting idea. Isn't it great how nature gives us all the answers...

"Nature shows us only the tail of the lion. But I do not doubt that the lion belongs to it even though he cannot at once reveal himself because of his enormous size" - Albert Einstein

__________________
"The sweat of hard work is not to be displayed. It is much more graceful to appear favored by the gods." -Maxine Hong Kingston
Reply
Anonymous Poster
#5

Re: Cheating Death: Therapeutic Hypothermia

11/28/2007 5:40 PM

references to "hyperthermia" should read "hypothermia". These are very different conditions!

Reply
Active Contributor

Join Date: May 2007
Location: Washington, DC
Posts: 16
#6

Re: Cheating Death: Therapeutic Hypothermia

11/29/2007 2:59 PM

Hi guest! I don't see any references to "hyperthermia" except yours... what are you referring to?

__________________
"The sweat of hard work is not to be displayed. It is much more graceful to appear favored by the gods." -Maxine Hong Kingston
Reply
Active Contributor

Join Date: Nov 2007
Location: South East England.
Posts: 23
#7
In reply to #6

Re: Cheating Death: Therapeutic Hypothermia

12/30/2007 5:54 AM

Try Wikipedia,

"Hyperthermia in its advanced state referred to as heat stroke or sunstroke, is an acute condition which occurs when the body produces or absorbs more heat than it can dissipate. It is usually due to excessive exposure to heat. The heat-regulating mechanisms of the body eventually become overwhelmed and unable to effectively deal with the heat, and body temperature climbs uncontrollably. This is a medical emergency that requires immediate medical attention."

and

"Hypothermia is a condition in which an organism's temperature drops below that required for normal metabolism and bodily functions. In warm-blooded animals, core body temperature is maintained near a constant level through biologic homeostasis. But when the body is exposed to cold its internal mechanisms may be unable to replenish the heat that is being lost to the organism's surroundings."

TrevorL

Reply
Anonymous Poster
#8
In reply to #7

Re: Cheating Death: Therapeutic Hypothermia

12/31/2007 3:21 PM

This blog discusses how some doctors are now using hypothermia to lower a patient's body temperature to slow down the metabolism and lessen the amount of oxygen the brain needs. This is important because this allows the body to respond to the stroke/heart attack and still meet the brain's requirements for oxygen. If a person is not placed under hypothermia their brain is then functioning at a higher rate along with their metabolism and therefore needs more oxygen. In this situation a lot the times the body is unable to supply the necessary amount of oxygen to the brain and therefore damage is caused because of a lack of oxygen which causes inflammation and swelling in the brain that has a tendency to damage neurons.


I don't understand your choice in explaining the differences between hypothermia and hyperthermia (though it is good for everyone to know the differences), if I mentioned in the blog hyperthermia I meant to have it as hypothermia. However I don't see this mistake, if you could point it out to me I would greatly appreciate it, and therefore can make the changes.

Reply
Active Contributor

Join Date: Nov 2007
Location: South East England.
Posts: 23
#9
In reply to #8

Re: Cheating Death: Therapeutic Hypothermia

01/01/2008 3:45 AM

Hi Guest, My posting was in reply to MintyFresh, #6, who referred to hyperthermia and seemed to require a definition.

Not everyone who takes part in this discussion is as familiar with the subject as you are. The two words are similar but have very different meanings and as you imply, it is vital that we all have the same definition for the same words, saves a lot of confusion.

TrevorL

Reply
Reply to Blog Entry 9 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Copy to Clipboard

Users who posted comments:

Anonymous Poster (2); jack of all trades (1); MintyFresh@GS (2); Steve Melito (1); TrevorL (2); unclefastguy (1)

Previous in Blog: The Science of Sports   Next in Blog: Airborne: A Cure for the Common Cold?

Advertisement