September 11, 2023
A Second World War-era innovation is being revived by a team of researchers in Toronto, that will improve care for trauma patients and possibly save lives of Canadian Armed Forces (CAF) members who are in combat or in remote locations. Defence Research and Development Canada (DRDC) is partnering with Canadian Forces Health Services, St. Michael’s Hospital, Terumo BCT and Canadian Blood Services to assess and validate a prototype freeze-dried plasma kit designed for prehospital use by first responders and CAF members.
Plasma is a component of blood that makes up more than half of the blood volume, and contains important clotting proteins that help stop bleeding.
When separated from whole blood, plasma looks like a pale-yellow liquid, as it is red blood cells that gives whole blood its red hue. The freeze-dried version looks like a soft yellow powder but regains it opaque consistency when it is rehydrated.
The prototype kit consists of separated freeze-dried plasma and sterile water that can be mixed quickly on-site, then administered intravenously to stabilize a trauma patient until they can get to an operating table.
“Freeze-dried plasma is lightweight, durable and portable, and can be rapidly reconstituted to treat severe bleeding, even in remote locations and the frontline of battlefields,” explains DRDC’s Dr. Henry Peng. “We are testing a product that could be part of every soldier’s kit so anyone who has lost a lot of blood could have access to this stabilizing treatment while they are being transported for urgent care.”
While transfusing whole blood would be the best-case scenario, whole blood cannot be freeze-dried and has a limited storage life, even with refrigeration.
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Defence Research and Development Canada is working with partners to develop a prototype freeze-dried plasma kit that could improve treatment in the field for bleeding.
Plasma is a component of blood that makes up more than half of blood volume, and contains important clotting proteins that help stop bleeding. A recent test shows the rehydrated plasma keeps its clotting ability to help stop bleeding.
Researchers are developing a prototype freeze-dried plasma kit that fits in tactical vests for Canadian Armed Forces members.
The kit has one unit of freeze-dried plasma and 250 mL of sterile water, each in a plastic bag, which is important for portability in combat settings.
The two bags can be attached and mixed on-site, and the rehydrated plasma can be administered through an intravenous line to stabilize a trauma patient until they can get to an operating table.
Early research
During the Second World War, Canadian researchers developed freeze-dried serum, which is a component of plasma. Serum contains minimal clotting proteins but is still important in maintaining blood volume and blood pressure. Freeze-dried serum is lightweight and able to be stored at room temperature, which made it a critical battlefield innovation at that time. The team was led by Dr. Charles Best, who is better known for his work in discovering insulin.
At the time, whole blood could only be stored for about a week with refrigeration, so most transfusions were done directly from a donor to a patient in field hospitals. By comparison, freeze-dried serum could be stockpiled on the front lines, then quickly rehydrated with water and administered to stabilize patients who were bleeding out.
After the Korean War, production of freeze-dried serum was stopped over concerns of transmitting viral hepatitis. Modern researchers renewed efforts to develop this product after safety concerns were addressed with improvements in screening processes for whole blood and plasma donations, testing procedures and pathogen reduction. Further improvements in freeze-drying technology also meant that modern researchers can now freeze-dry plasma itself, which contains the clotting proteins that are important to stop bleeding that were missing in freeze-dried serum.
Currently CAF medics and first responders rely on saline solution to maintain blood pressure while trauma patients are being transported to a location where they can receive further care. Whole blood now has a shelf life of 3 weeks with additives and refrigeration, which is why whole blood is transfused at the hospital. Saline is an imperfect temporary measure because it dilutes the important clotting proteins that stop bleeding, and makes the blood more acidic. Freeze-dried plasma is light weight and can be stored for two years without requiring refrigeration. This makes freeze-dried plasma easier to bring wherever CAF members need to be, whether in remote locations, such as the Arctic, or at the frontline of the battlefield.
Past meets present
Researchers recently discovered a glass bottle containing freeze-dried serum from 1943 at Connaught Labs Museum in Toronto.
“We were curious if the serum could still be re-hydrated 80 years later,” says Dr. (LCol) Andrew Beckett, a trauma surgeon at St. Michael’s Hospital and Canadian Forces Health Services, adding that the team decided to test it at the same time as a sample of the prototype under development.
Researchers from Defence Research and Development Canada rehydrated a sample of freeze-dried serum from 1943 and a sample of freeze-dried plasma from 2019.
While the older sample did not completely reconstitute, the sample still exhibited properties which help increase blood volume of a severely bleeding patient, known as "colloid properties.” DRDC researcher Katy Moes successfully reconstituted and tested the current prototype at the DRDC laboratory in Toronto. The current prototype demonstrated global and specific clotting activities, which supports further development for emergency resuscitation of severely injured patients.
“Although most of the proteins in the older sample likely degraded, it is interesting that the sample still showed some colloid properties 80 years later,” says Dr. (Cpl) Kanwal Singh with St. Michael’s Hospital and Canadian Forces Health Services. “The clotting activity we saw in the new prototype indicates that freeze-dried plasma would be beneficial in a severely bleeding trauma patient.”
These results are encouraging and support the goal of developing a freeze-dried plasma trauma kit for the CAF. The researchers are planning a clinical trial, which is a necessary step for Health Canada approval.
Research team:
- Dr. Shawn Rhind, DRDC
- Dr. Henry Peng, DRDC
- Katy Moes, DRDC
- Dr. (LCol) Andrew Beckett, St. Michael’s Hospital and Canadian Forces Health Services
- Dr. (Cpl) Kanwal Singh, St. Michael’s Hospital and Canadian Forces Health Services
- Dr. Dana Devine, Canadian Blood Services
- Craig Jenkins, Canadian Blood Services
- Dr. Chantale Pambrun, Canadian Blood Services
- Dr. William Sheffield (McMaster University)
- Dr. Christopher Rutty – Connaught Laboratory Museum. Toronto