How much blood can a person lose within a 18 to 24 hour period and still survive? What about 9 units?

Question

The blood loss was a result of a central line being placed in an artery instead of a vein. The bleeding occurred between 7pm and 11 am the next morning. Nurses could not stop the bleeding and were changing soaked dressing pads, sheets and the patient's gown every hour throughout the night. No doctor came to check on the excessive bleeding during the night. There were no transfusions until approx. 18 hours after of bleeding started. Then doctors transfused 9 units FFP and blood STAT. 2 more units were transfused the next morning. 11 units total within approx a 32 hour timeframe. Can someone survive and recover after such trauma? As a result of the STAT transfusions, the patient had large, hard lumps or clumps form on her back, shoulders and chest. What was that?

Answer 1

If the person is receiving blood transfusions to replace the blood they are losing then the amount of blood loss they can tolerate is much more than 9 units. I recall a patient who lost (and received) 110 units of blood during a multivisceral transplant and survived. The operation lasted for close to 24 hours.
If you mean how much blood they can lose without receiving blood transfusions and survive, the number would be about 30 to 40% of the blood volume, about 5 units for a normal sized adult and even that assumes that they are receiving IV fluids.

Answer 2

The average volume of blood in an adult male is 5-6 liters, about 1.5 gallons. I don't know how to answer your question precisely, but if someone is getting continual transfusions, they can lose that much blood, because the bood volume remains elevated from the transfusions. This might happen during a very long surgery. (A surgical proceedure would not last as long as 18 hours, though.)