Thawed Plasma

In simple terms, Thawed Plasma is simply a new name for a previously frozen plasma product that has been thawed for more than 24 hours and less than 5 days. This product is incredibly useful for hospitals that serve patients in immediate, urgent need for plasma, especially trauma/massive transfusion patients. The terminology is confusing at first, but keep reading and I’ll try to explain!

The two most common plasma products used in the US for transfusion are called Fresh Frozen Plasma (FFP) and Plasma Frozen within 24 Hours of Collection (PF24). When either FFP or PF24 is thawed for transfusion, the thing we prefer to do is transfuse it right away. But if that doesn’t happen, the product must be stored in the refrigerator (at 1-6C) until transfusion. According to the FDA, that time in the refrigerator can’t exceed 24 hours after thawing.

Quick sidebar: When a trauma patient or other massively bleeding patient needs urgent transfusion, modern practice is to give units of plasma in equal quantities to units of red blood cells (with a platelet unit given every time we give 4-6 units of RBCs/plasma). Simply put, we don’t have time to wait for FFP or PF24 to thaw when one of these patients presents! This is why we keep units of previously thawed either group AB or, more commonly, group A FFP or PF24 in a “ready to use,” thawed state). If we just stuck with the FDA rule limiting thawed FFP/PF24 to a 24 hour post-thaw shelf-life, we would have the potential of those units expiring and being wasted if no patient in urgent need presented during that 24 hour period.

Simply put, transfusion services strongly prefer to keep previously thawed plasma around for longer than 24 hours to avoid expiration and meet operational needs, and thankfully, we have a pathway to do so. Both the “Circular of Information” and AABB Standards describe a pathway to allow us to use that thawed product beyond the FDA limit of 24 hours. The trick, though, is that if you are going to transfuse it more than 24 hours after you thaw it, you have to give the product a new name! That new name? You guessed it: “Thawed Plasma.” I almost always refer to it as “Thawed Capital P Plasma” to distinguish it from a generic “thawed plasma” product.

After the product formerly known as “FFP” or “PF24” is re-labeled as “Thawed Plasma” (note the CAPITAL “T” and “P”), it is stored under the same conditions as it was for the first 24 hours after thawing (i.e., 1-6C) for up to 5 days. As mentioned above, the most prominent use of Thawed Plasma is for trauma or other massively bleeding patients, where it serves as a “bridge” until freshly thawed FFP/PF24 specific for the patient’s blood type can be ready to transfuse (in this way, the product is similar to the lesser-used “Liquid Plasma“). Many facilities will also use Thawed Plasma for non-trauma patients, for exactly the same indications as the original plasma component (with the possible exception that, due to the documented decrease in factor VIII and to a lesser extent factors V and protein S, some will avoid use in cases of consumptive coagulopathies like DIC).

Here’s the thing: This is one of the few processes we use in the US blood banks that is not recognized by the FDA. However, FDA has chosen not to weigh in on this (so far), so doing this is also not prohibited by FDA!

You should also know that you can do the same “new name” thing for the less commonly used product called “PF24RT24″, as well as for the REALLY uncommonly used Plasma Cryoprecipitate Reduced (technically, that product must be re-labeled as “Thawed Plasma Cryoprecipitate Reduced,” but the principle is the same).

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