From Simple English Wikipedia, the free encyclopedia
A halfliter of blood (enough for oneblood transfusion). If anaverage adult lost 5 to 8 times this much blood, they could die from exsanguination
Exsanguination is losing enoughblood to causedeath. A person does not have to lose all of their blood toexsanguinate. People can die from losing half to two-thirds of their blood.[1]
Theaverage adult has about 4 to 6liters of blood (9 to 12 US pints) in their body. The average man has more blood than the average woman (who has 4 to 5 liters), and people who weigh more or are taller than others have more blood.[1] This means a person can die from losing 21/2 to 4 liters of blood. To compare, this is five to eight times as much blood as people usually give in ablood donation.[2]
Babies (have about one cup of blood) and children have much less blood than adults, and can exsanguinate much easier by losing less blood than adults.[3] Theliver can and does store up to one pint of blood.
Exsanguination is often calledbleeding to death orbleeding out. It is amedical emergency.
"External" means "outside the body." External bleeding is visible - it can be seen outside the body. For example, a person who cuts their hand and has blood on their hand is having external bleeding.
"Internal" means "inside the body." Internal bleeding cannot be seen, because it is inside the body. For example, a person who is bleeding into theirbrain because of astroke is having internal bleeding.
Sometimes, bleeding can be both internal and external. A person can exsanguinate from internal bleeding, external bleeding, or both.[5]
Exsanguination is usually caused by majorblood vessels getting injured or breaking open. Smaller blood vessels bleed less, and bleed slower, so it is harder to exsanguinate if they are injured.[1]
Injuries that hurt majorarteries, like thefemoral artery (in red), can cause exsanguination
Exsanguination can be caused by trauma (injuries). Out of all people who die from injuries, 30-40% die from exsanguination.[6] Up to half of these people (33-56%) die before they even get to the hospital.[6]
Penetrating trauma (an injury where something breaks the skin) is one of the most common causes of exsanguination.[7] This is especially true forgunshot wounds to places like theheart,chest, orhead, which all have major blood vessels in them.[6][7]
Other injuries that can cause exsanguination include:[6]
Exsanguination is one of the most common causes of death insoldiers atwar.[8][9] It is usually caused by gunshot wounds, motor vehicle accidents, orexplosions.[8][9]
Exsanguination afterchildbirth is most common in countries colored black and red on this map. It is least common in countries colored blue and purple.
Some medical problems can make a person exsanguinate by bleeding internally. These problems include:[3][5]
Ananeurysm in the aorta that breaks. This can cause a person to exsanguinate in just a few minutes.
Sepsis, which can cause theinfection to eat away at the walls of the blood vessels. Eventually the walls break and the blood vessels start to bleed.
Bleeding afterchildbirth. Around the world, one woman dies every two minutes from exsanguination after childbirth. Most of these deaths happen indeveloping countries.[10] This is also commonly caused byVon Willebrand disease
Figure A shows a normalaorta. Figures B and C showaneurysms in parts of the aorta. When an aneurysm breaks (like a poppedballoon), a person can exsanguinate in just minutes.
If a person is losing blood very quickly (for example, from a broken aortic aneurysm), they will only be conscious for 20 seconds to a few minutes.[5] If blood loss is slower, and the person does not get medicaltreatment, they may be conscious for a few hours. However, they will get more and moreconfused and tired as they lose more blood. Eventually the person will go into acoma because there is not enough blood left in their body to bringoxygen to their brain. Finally theirheart will stop and they will die.[5]
Coagulopathy means that the blood no longerclots normally.[11] When a person loses blood, they also lose theplatelets and blood-clottingproteins the blood carried. These platelets and proteins make the blood clot.[12] If a person loses too much blood, they will not have enough platelets or proteins left to make the blood clot.
Acidosis means that the body makes too muchacid.[1] Usually, the body makes energy out of oxygen carried in the blood andglucose (sugar); this is calledaerobic respiration.[13] If a person loses a lot of blood, there will not be enough oxygen in the blood that is left to make energy this way. The body switches toanaerobic respiration and makes energy out of glucose without needing oxygen. However, this creates many acidic waste products (chemicals that the body does not need, which are left over after the body doeschemical reactions).[13] Eventually, these waste products can build up so much that they poison the body. This is called acidosis.[3]
When the heart does not get enough blood, it can startbeating in ways that are not normal.[3] When this happens because of exsanguination, it usually means that the patient is close to dying.[6]
If a person loses enough blood, they will go intoshock.[1] This means the body's most importantorgans are not getting the blood, oxygen, andnutrients they need to survive. It also means that the body is not able to get rid of waste products, like acids. If shock gets bad enough, it will kill the person.[3]
If the person is bleeding from an arm or leg, lifting the arm or leg above the level of the person's heart
Making atourniquet and wrapping it tightly above where the person is bleeding
Laying the person down and raising their legs, if possible
If the person is coughing or vomiting blood, turning them on their side so they do not choke
Keeping the person warm
Trying to help the person stay calm
If possible, a person giving first aid should wear gloves any time they touch another person's blood. The sick or injured person may have aninfection that can be spread through blood, likeHIV orhepatitis. Wearing gloves will protect the person giving first aid from getting these infections.[14]
First aid saved many lives during theBoston Marathon bombings, when ordinary people used belts for tourniquets or used their own hands to press against bleeding wounds.[15] The three people who died in thebombings died right away.[15] There were many other people who were hurt badly enough that they could have exsanguinated. For example, some people'slegs were blown off by the bombs. However, because of the help of ordinary people giving first aid (and because ofemergency medical services), everyone who did not die right away survived.[15]
Alcoholism. Drinking too muchalcohol candamage the liver and also cause alcoholichepatitis. If the liver is damaged, it cannot make blood-clotting proteins (likefibrinogen) as well as a healthy liver does.[16] This makes alcoholics more likely to bleed dangerously if they get hurt. Liver damage can also lead to a problem calledesophageal varices, which can cause a person to exsanguinate bythrowing up blood.[16]
Advancedcancer. Of everyone who has advanced cancer and is not getting treated for their cancer, up to one in 10 people have dangerous bleeding.[5]
↑13.013.1"Respiration".Chemistry for Biologists. Royal Society of Chemistry. 2004. RetrievedFebruary 16, 2016.
↑14.014.1"Severe Bleeding: First Aid".Mayo Clinic. Mayo Foundation for Medical Education and Research. October 21, 2014. RetrievedFebruary 16, 2016.
↑15.015.115.2Biddinger, PD; Baggish, A; et al. (2013). "Be Prepared – The Boston Marathon and Mass-Casualty Events".New England Journal of Medicine.368 (21):1958–1960.doi:10.1056/NEJMp1305480.PMID23635020.{{cite journal}}: CS1 maint: multiple names: authors list (link)
↑Zhang WB; Wang WY; et al. (2010). "Risk Factors of Mortality in Non-Trauma Exsanguinating Patients that Require Damage Control Laparotomy".ANZ Journal of Surgery.80 (4). Royal Australasian College of Surgeons:258–64.doi:10.1111/j.1445-2197.2009.05087.x.PMID20575953.S2CID29179840.{{cite journal}}: CS1 maint: multiple names: authors list (link)
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