Quality and Training Supervisor Tola Elegbe on thawing times and haemostatic assessment.
There is growing demand for plasma to be more rapidly available for the management of major bleeding, although the recent approval of extended shelf life of thawed fresh frozen plasma (FFP) to 120 hours has addressed this and improved the early availability of plasma for adult patients during major haemorrhage and has reduced unnecessary wastage. But studies show that the haemostatic qualities of FFP deteriorate when the shelf life of a thawed component is extended beyond 24 hours.
Therefore, it could be argued that the impairment in haemostatic qualities of extended thawed FFP could translate to lesser efficacy in the management of major bleeding, although clinical studies are required to confirm this.
In the case of paediatric patients who are bleeding, FFP components (methylene blue-treated FFP (MBFFP) and solvent detergent FFP (SDFFP)) are still thawed on demand, because their shelf life remains 24 hours after thawing.
This means that in these patients the national recommendation for delivering a 1:1 ratio of FFP with red cells in trauma bleeding situations is not met.
New technologies
Recently, there has been an increased interest in replacing fibrinogen early (with cryoprecipitate) for the treatment of major haemorrhage associated with trauma and obstetrics. The current shelf life of cryoprecipitate after thawing is four hours, and in vitro data from NHS Blood and Transplant has confirmed that its shelf life could be extended for up to 72 hours from the haemostatic qualities point of view. However, unlike extended thawed FFP, extended thawed cryoprecipitate will need to be kept at room temperature and, therefore, there is a potential risk for bacterial growth.
The ideal situation would be to have a faster thawing method than the current method, which would allow for quicker delivery of plasma to patients and thawing of plasma on demand to reduce unnecessary wastage, as even with the availability of extended thawed FFP we will not be able to eliminate wastage. It would also mean better quality (and safer) plasma components for patients.
The recommended temperature for thawing plasma products is 37oC, but new technologies on the market are capable of thawing plasma at up to 45oC. This could contribute to faster thawing times making plasma more rapidly available for the management of major haemorrhage. Barkey has developed the plasmatherm, a water-based plasma thawer with the ability to thaw frozen plasma in 15 minutes, using a temperature range
of 37oC to 45oC, and for smaller volume components, such as cryoprecipitate and paediatric units, the thawing time can be further reduced, if temperatures higher than 37oC are used.
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