Why don’t people go brain dead or get brain damage in surgery when on heart-bypass machine?
I was just watching surgery of a woman, and her heart and her whole body was cooled so she could have some blood clots removed from her lungs.
They stopped her blood circulation and she flat lined. They didn’t explain but I assume she was not receiving oxygen. How is it possible to avoid brain damage in the patient when there is no oxygen coming in?
When your body temperature drops or the body is deprived of oxygen, the body starts to protect itself.
It starts with your fingers and toes, diverting blood away from them so that more important parts of the body can still function. This goes on with the limbs and organs until the last vital organs (brain, heart, lungs, liver, kidneys) are still getting blood and oxygen. The temperature slows down body processes so that less oxygen is used by the remaining organs.
The brain is the last organ to shut down. It runs on the very minimum amount of oxygen and glucose possible while in the "cold" state.
There are also "autoperfusion" machines that pump blood to the lungs and throughout the body during some operations. A ventilator makes the lungs work. This means the mechanical heart and lungs keep the body alive while the real heart and lungs are inactive.
BTW, it’s called bypass surgery because they are bypassing the Coronary Artery, not because of the perfusion machine.
January 21st, 2010 at 10:37 pm
Magic
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January 21st, 2010 at 10:44 pm
That is really interesting. I never knew that they don’t recieve oxygen. I will give you a star because I would really like someone to explain that.
http://answers.yahoo.com/question/index?qid=20071216205424AAb9Mfe&pa=FYd1D2bwHTHwLb1uEu05R1cYuckdM8myCNy9Z9cpfyEaOQ–&paid=asked&msgr_status=
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January 21st, 2010 at 11:32 pm
The brain can survive without oxygen for roughly 4minutes then the cells start to die.
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January 22nd, 2010 at 12:18 am
the machine keeps the oxygen and blood flowing but the surgery time is limited so they must work fast
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January 22nd, 2010 at 12:32 am
She flatlined because her heart was not producing any electrical signals. The EKG machine that would show her flat-lining only represents the electricity in the heart that causes heart beats. However, they had her hooked up to a heart-lung machine that was doing the work for her heart while it rested, so blood was still circulating.
That’s why the surgery is known as bypass- because the heart-lung machine bypasses the heart and provides circulation and oxygenation itself.
References :
EMT, pre-nursing
http://www.cincinnatichildrens.org/health/heart-encyclopedia/treat/surg/bypass.htm
January 22nd, 2010 at 12:59 am
they are receiving oxygen while on a bypass. the blood is oxygenated with the bypass machine. that is what it is for.
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January 22nd, 2010 at 1:26 am
When your body temperature drops or the body is deprived of oxygen, the body starts to protect itself.
It starts with your fingers and toes, diverting blood away from them so that more important parts of the body can still function. This goes on with the limbs and organs until the last vital organs (brain, heart, lungs, liver, kidneys) are still getting blood and oxygen. The temperature slows down body processes so that less oxygen is used by the remaining organs.
The brain is the last organ to shut down. It runs on the very minimum amount of oxygen and glucose possible while in the "cold" state.
There are also "autoperfusion" machines that pump blood to the lungs and throughout the body during some operations. A ventilator makes the lungs work. This means the mechanical heart and lungs keep the body alive while the real heart and lungs are inactive.
BTW, it’s called bypass surgery because they are bypassing the Coronary Artery, not because of the perfusion machine.
References :
Registered Nurse, ACLS, EMT-P
January 22nd, 2010 at 2:16 am
http://www.boston.com/news/globe/health_science/articles/2004/09/21/heart_patients_mental_decline_baffles_doctors/?page=1
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January 22nd, 2010 at 2:39 am
Because the by-pass machine cleans the blood and re-oxygenates it then it circulates it round the body including the brain , the only part not getting blood is the part being operated on , the blood is " By passed the operation site hence the name " By-pass ", Yes the blood is also cooled which enables the patient to be on by pass longer , After the opp the blood is reheated and the shunt removed to restore circulation . Note !! I am NOT a doctor but I have been on by pass twice and I did not suffer brain damage ( I am sure , well nearly !!)
Cheers Pete
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UOL
January 22nd, 2010 at 3:02 am
The heart and lungs are stopped and re-routed to a heart-lung machine which does the work of the cardiopulmonary system while the patient has her surgery. The brain still receives the appropriate amount of oxygen needed; and the heart-lung machine routes oxygenated blood to the extremities to keep the tissue there alive.
If a patient goes about 4 minutes without oxygen then brain damage can occur. They cool the body so that the tissue will not need as much oxygen.
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