Balancing blood loss with blood transfusions
October 18, 2013 7:20 AM   Subscribe

How long / how well would a person survive if they were being regularly drained of blood but receiving blood transfusions of the same volume? What health complications might arise?

This is for NaNoWriMo, honestly. For the purposes of this question, the person would be sedentary, receiving adequate food and, initially at least, in good health.
posted by daisyk to Health & Fitness (17 answers total) 4 users marked this as a favorite
Isn't that basically what happens during major surgery? So much blood is being lost, and "transfusion" is basically just pouring new blood through your body until all the holes are closed up and the blood can stay in there.
posted by entropone at 7:46 AM on October 18, 2013

Here is a list of possible complications from blood transfusions. I suspect the risks would increase as the transfusions continue.
posted by blue_beetle at 7:55 AM on October 18, 2013

Hemodialysis and hemodiafiltration are essentially processes for doing this with the return being the patient's own cleaned blood and often added fluids and electrolytes.
posted by The 10th Regiment of Foot at 8:04 AM on October 18, 2013 [2 favorites]

"Presented below is a description of massive blood loss and the inherent problems associated with large volume blood transfusions. Following this is a suggested protocol for guiding management of the patient receiving a massive transfusion for haemorrhage. ... Massive transfusion is arbitrarily defined as the replacement of a patient's total blood volume in less than 24 hours, or as the acute administration of more than half the patient's estimated blood volume per hour."

Looks like it's definitely doable for a while but presents risk of several different complications, many of which get worse the more blood is transfused (e.g. thrombocytopenia becomes a risk once at least 1.5 times the patient's blood volume has been transfused).
posted by jedicus at 8:05 AM on October 18, 2013

When my father was on regular (3x/week) hemodialysis he had to be constantly monitored for dangerous blood pressure fluctuations. So that might be something to consider. Good luck in your NaNo.
posted by Infinity_8 at 8:10 AM on October 18, 2013

Here's a 1987 report on outcomes for 56 patients that received transfusions of at least 2 times their blood volume. Overall survival was 39%. Now, none of these people were "initially in good health" per your hypothetical, so take those survival rates with a grain of salt.

Here's a 1991 study of outcomes in 29 patients who received at least 4 times their blood volume. In that study the survival rate was 38%. But "only one patient survived when the amount of transfusions exceeded 50 units." Again, obviously these people were receiving a lot of blood because something else was severely wrong with them, so it's not clear how applicable it is to your question.

Here's a 2002 article (full text) [pdf] analyzing a subgroup of 44 trauma patients who received more than 50 units of blood. It found a 43% survival rate. Interestingly, no significant difference was found between patients who received 51-75 units and those that received more than 75 units. Also, if you look at Table 5, it's clear that most of the nonsurvivors died from their initial trauma, not from complications due to the transfusion itself. These two facts suggest to me that, in a controlled setting, a person's blood volume reasonably safely be replaced several times without the person dying.
posted by jedicus at 8:16 AM on October 18, 2013

Per the CDC, iron overload would be an issue, since getting a non-matching blood transfusion could cause an antibody reaction and excess iron received from blood transfusions is stored in your organs.

Per NIH, an acute immune hemolytic reaction could occur if you get a transfusion that is incompatible with your blood type or Rh factor, because your body will be attacking the incoming red blood cells. Graft-vs-Host Disease is a factor if the blood is not irradiated before transfusion.

Exposure to blood-transmissible viral infections (hepatitis B, vCJD, malaria, Epstein-Barr virus), bacterial contamination, and the gradual development of a sensitization to leukocyte or plasma antigens would be ongoing risks.

Here's a very detailed review of basically everything that could go wrong: risks and complications of blood transfusions (PDF) -- and a brief overview of other aspects, including complications of massive blood transfusion (PDF), including fluid overload, impaired oxygen delivery, hypothermia, coagulopathy, and an excess of calcium, acid, or potassium.

If your blood draining and transfusion will not be simultaneous, you might want to look into some of the the body's response to varying degrees of blood loss (PDF).
posted by divined by radio at 8:16 AM on October 18, 2013 [1 favorite]

The worst complications of blood transfusion are often the result of storage or clerical errors. So your hypothetical patient could get a serious infection (not just HIV or Hepatitis but fulminant bacterial sepsis, for example). The only two times I have seen a patient get ABO incompatible blood were the result of checking the paperwork improperly before transfusing a patient.
posted by TedW at 8:16 AM on October 18, 2013

I think infinity_8 is onto something re: hemodialysis. The process essentially takes your blood out of your system, passes it through filtration, and then flows it back in. Because the blood is clean, it eliminates most of the issues like viruses or incompatibilities that you might have from getting transfusions. My family member on dialysis sometimes became weak or nauseated, but that was usually when they didn't take off the right amount of fluid. (Remember that dialysis is for removing fluids and toxins.)

Article about ICU patients who are on continuous dialysis.

Article on continuous renal replacement -- which is continuous filtering.

If you're seeing the transfusion as something that = clean, filtered blood, it sounds like someone could do this a very long time.
posted by mochapickle at 9:00 AM on October 18, 2013

In the last three months of his life, Hirohito received 31 liters of blood—which works out to slightly more than a pint a day, I think, and probably about 7 complete replacements of all the blood in his body.

He ultimately died of pancreatic cancer, which could have killed him that quickly even without all the internal bleeding. Just as a data point.
posted by adamrice at 9:17 AM on October 18, 2013

No transfusion is ever a perfect match for the recipient's blood, and the quality of the match would decrease with the available supply. There's a lot more to it than simply matching ABO and Rh blood types. Therefore, a person receiving "massive" transfusions would be exposed to a higher risk of transfusion reaction than a person receiving only a few units.
posted by shiny blue object at 10:09 AM on October 18, 2013 [1 favorite]

I personally went through 45 units of blood in two weeks when I was hospitalized with internal bleeding in my small intestine ten years ago. That's how long it took them to track down where I was actually bleeding from.

I was anemic for a few months afterwards recovering, but I am not sure how much of that was due to the constant transfusions or not eating for the two weeks. I also have a weird bleeding disorder* that complicated it as well.

posted by SteveFlamingo at 1:44 PM on October 18, 2013

Thank you all so much, these are brilliant answers. I'm on my phone in the mountains right now, but will go through all the links when I get home on Monday.

One extra question that did occur to me is this: since one of the functions of blood is to bring nutrients from the digestive system to the rest of the body's cells, would this be very disrupted? That is, would a lot of the energy etc. from food eaten be removed from the body before it could be used?

I haven't pinned down numbers yet, but I'm envisioning this 'treatment' taking place over a few weeks, with a pint or several being taken out and replaced per day, probably not simultaneously.
posted by daisyk at 2:19 PM on October 18, 2013

The energy transfer from food to the body is not an instantaneous thing after eating, it's a prolonged process, and the body has the ability to store energy and release it from the liver (gluconeogenesis).

This allows a person to compensate for loss of nutrition from other sources over the short term. So as long as your subject is eating, the loss of blood sugar in the blood being removed should not be an issue in terms of starvation.

As for other nutrients such as electrolytes, remember that you are not just taking them away, you are adding them with the blood transfusions, and so there are problems with both of those things. Certain electrolyte levels tend to be deranged by blood loss/transfusion (i.e. hypocalcemia which is not enough calcium, hyperkalemia which is too much potassium), and that is what you will see referenced in the links above.

At least some of those links are definitely not targeted towards the lay public. If you need help deciphering them, you can memail me.
posted by treehorn+bunny at 9:13 PM on October 18, 2013

A haematologist giving a lecture at my school described a blood transfusion as an organ transplant, which is a very good way to give it some respect. As with any organ transplant, no matter how well you match it (and we only match a few out of hundreds of potential match points) there's immunological issues. After each transfusion, your immunological profile changes as you form antibodies to the red blood cells in the donor blood, making it progressively more difficult to find matches.

If you have a look at all the complications of a single transfusion, it's worth thinking that they are more likely to happen if you repeat the procedure dozens of times i.e. line site infection, incorrect match, contaminated blood.
posted by chiquitita at 10:37 PM on October 18, 2013

I haven't pinned down numbers yet, but I'm envisioning this 'treatment' taking place over a few weeks, with a pint or several being taken out and replaced per day, probably not simultaneously.

Transfused blood doesn't come in pints anymore. A typical unit of blood is around 250 to 300 milliliters; a pint is about 475 milliliters. Every unit of blood has a slightly different volume.
posted by shiny blue object at 10:56 AM on October 20, 2013

For more information, especially on the mechanics of the process, you might want to look at a copy of Wheelmen, the new book about Lance Armstrong. Apparently what you describe was a big part of their doping program, albeit with the patient recieving his own blood back.
posted by TedW at 8:54 AM on October 22, 2013

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