When Does a Person Require Blood Transfusion?

Sometimes, it’s hard to know when writing a scene when to pull the big guns out. If you have a character that is bleeding a lot (by whatever mechanism) when should you think about giving them blood? Or, better yet, when will the lack of blood begin to hamper their ability to function.

Fairly consistent among resources, hemorrhagic shock (shock related specifically to blood loss) is a life-threatening condition that results when you lose more than 20% or 1/5th of your blood supply. Patients will feel lightheaded, dizzy. Their respiratory rate and heart rate will be elevated. Their blood pressure might be low. They’ll look pale, pasty. Their skin might feel cool, clammy, dough-like.

But exactly how much blood does that translate to? I actually found this nifty little calculator that will give you a person’s estimated blood volume based on their age, sex, and weight. For instance, a man weighing 100 kg has an estimated blood volume of 7,500 ml. So losing 20% of his blood volume would be 1,500 ml of blood or approximately 3 pints of blood. A pint of whole blood (what you would donate) is approx 500 ml. A woman of the same weight has only 6,500 ml of circulating blood. An infant weighing 10 kg has only 800 ml of blood. You can see how that 20% translates much differently depending on the characters age, sex and weight.

History of Blood Transfusion

For historical authors, it’s important to know when a medical advancement takes place for novels that include these medical details. While researching a medical question for an author regarding blood transfusion I came across a very good timeline concerning this medical advancement. You can find that article here.  Additional resource found here.

1628: Dr. William Harvey discovers blood circulation.

1655: Dr. Richard Lower performs successful animal to animal blood transfusion using dogs.

1818: Dr. James Blundell performs first person to person blood transfusion. Blundell is a gynecologist and uses blood transfusions to treat postpartum hemorrhage.

1840: Successful blood transfusion of patient with hemophilia.

1901-1902: Karl Landsteiner discovers blood types. This is an important advancement because giving the patient the wrong blood type can well . . . kill them.

1914-1918: Dr. O.H. Robinson finds effective anticoagulant that aids in long-term blood storage. Adolf Hustin is also credited with discovering an anticoagulant as well.

1920’s: Percy Oliver develops donor system for British Red Cross.

1932: Leningrad Hospital houses first blood bank.

1939-1940: Rh Blood group is discovered which is determined to be the cause of most blood transfusion reactions.

1941: Red Cross U.S.A. is started.

1950: Use of plastic bags makes collecting and storing blood easier. Before this they used glass bottles. This I cannot imagine.

1972: Apheresis is discovered which can remove one component of blood and return the rest to the donor.

1983: Stanford Blood Center begins screening donated blood for AIDS.

1985: HIV screening licensed and implemented.

1990: Hepatitis C Screening initiated.

It’s amazing to look back on just how much was accomplished in blood transfusion, blood banking, and ensuring a safe blood supply in the 20th century.

Author Question: Transfusing Blood Post EMP Blast

Alyssa Asks:

An EMP took out all electricity 2 years ago— meaning no electricity, refrigeration, or other modern medical machines. The city has been isolated since then. Ruling gangs have raided the hospitals, but our gang of survivors managed to snag a number of essential hospital supplies including a field transfusion kit.

Patient is 6 years old. She has lost a large amount of blood from a scalp wound. They don’t know how much blood since it’s dark and they weren’t there when it happened, but she’s sheet-white, cold and clammy skin, blue lips and fingernails, shallow breath, quick pulse but low blood pressure. No access to Saline. Looks like blood is the only option.

Our nurse, she tells the others about the risks, even though the donor and recipient have the same blood type. Antibodies causing a reaction, infection, too much blood, etc. But it’s a dire situation.

Could they run an IV from the donor into a blood bag using gravity? Bags suspended in cold water to keep it cold and inject anticoagulant into the bag port once the blood starts filling it?

They’d only use one unit. Once they fill the bag, they’d use another blood tube to run it into an IV attached to our young recipient. Again, they’d use gravity, but the girl would be on a table and the blood bag suspended above her, maybe hanging on a hanger on a back of the door. Would this work?

Jordyn Says:

Thanks, Alyssa, for sending me your question. It is fairly complicated so I’m going to give a little background.

First of all, kids do not get the same amount of blood as an adult. We transfuse kids based on their weight. Your average 6 y/o weighs about 22 kg. Kids get 10ml/kg for their transfusion volume so this child needs approximately 220 ml of blood. We also don’t routinely transfuse whole blood. What we give is packed red blood cells— exactly as the name sounds. One unit of whole blood is split up into many different parts (packed red blood cells, platelets, and plasma).

What you’re talking about is giving whole blood which will lessen the amount of packed red blood cells your patient is getting. I’d stick with transfusing about 200 ml of whole blood as a marker to start. One unit of blood can hold up to 525 ml so your patient would need roughly half of one bag. It will be hard for your character to measure that in this situation so the nurse will have to go off improvement of her patient’s vital signs. These would include improved color, warmer skin, decreased heart rate and increasing blood pressure.

Bags that collect blood already have a component inside to keep the blood from clotting so I don’t think I’d even worry about an anticoagulant. I don’t even know that you’d really need to worry about cooling the blood. Collection takes somewhere between 10-30 minutes depending on the size of the vein accessed. Usually for blood collection the antecubital vein is used (the one at the crook of your elbow).

While the blood is being collected from the donor (yes, by gravity— the bag lower than the donor), the nurse can start an IV in her patient. You would need a set of IV tubing to puncture the blood bag, prime the tubing with the blood, and then give it to your patient. No air in the line, please. Hanging the unit by any means possible is fine as long as it is higher than the recipient.

Usually, blood is given with a filter in the line so if they had stolen a blood transfusion field kit then hopefully this would be part of it.

Your other option is to do old style person to person transfusion of which you can see a photo here and not mess with collecting the blood at all.

Hope this helps and good luck with your story!

Religious Objection to Medical Care

Some religions object to medical care. Some believe in faith-healing. Other’s will accept some medical treatment but object to some procedures such as blood transfusions.

When I worked in the pediatric intensive care unit, one of these instances arose. The child was on a breathing machine and not doing very well. The patient’s hemoglobin level was low. You may know this as anemia. However, that’s just one type of anemia. What’s hemoglobin? It’s the part of your red blood cell that carries oxygen. When you don’t have enough hemoglobin to carry oxygen, your cells begin to starve and die. This leads to shock and death. It doesn’t matter how much oxygen we deliver, if there’s nothing to carry it to those individual cells, the patient can still die.

This problem is easy to solve. We give the child a blood transfusion. The parents, based on their religious beliefs, refused. This child’s levels were so low, he was at risk for complications and he’s already critically ill. It won’t take much to tip him over the edge. What are the options?

In pediatrics, often tests can be run with a lot less blood so we do micro-sampling and keep track of every drop of blood we take. Micro-containers generally fill with about a 1/2ml of blood whereas adult tubes take up to 3ml’s. Generally, patients in the ICU get labs every day to track their progress. The physician may choose to decrease the amount of labs done on a daily basis to conserve blood.

We ended up getting a court order to transfuse blood. The ICU docs were willing to respect the parent’s position up to a point, but they were not willing to let the child die.

Imagine being the nurse at the bedside in the morning, trying as best as you can to only take a small amount of blood. Then getting the results back and wondering if you’ll have to be the one to transfuse this patient.

The child survived and ended up not getting a blood transfusion and actually did really well. The nursing staff met with the family and a member of their church to discuss the issues that surrounded their child’s care. A nurse asked the mother, “What would it have been like for you if we did give your child blood?” The mother responds, “It would have been like you raped my baby.”

Those are strong, powerful words. I remember them to this day. Enough conflict? I think so and I definitely felt it at the time.