Past meets present: Reviving 80-year-old Canadian dried serum from World War II and its significance in advancing modern freeze-dried plasma for prehospital management of haemorrhage.

During World War II, Charles H. Best utilized Charles R. Drew's plasma isolation and drying technique to lead Canada's initiative to provide dried serum as a means of primary resuscitation for British casualties on the frontlines. Serum was likely utilized over plasma for its volume expansion properties without the risk of clotting during prolonged storage. We reconstituted dried serum from 1943 and discovered intact albumin, as well as anti-thrombin, plasminogen, protein C and protein S activity. Proteomic analysis identified 71 proteins, most prominent being albumin, and positive for hepatitis B by serological testing. Transmission of blood-borne diseases ended the programme, until modern advances in testing and pathogen reduction revived this technology. We tested the latest iteration of Canadian freeze-dried plasma (FDP), which was stored for 4 years, and demonstrated that its clotting capacity remained equivalent to fresh frozen plasma. We recommend that FDP is a strong alternative to contemporary prehospital resuscitation fluids (e.g. normal saline/lactated Ringer's) in managing prehospital haemorrhage where whole blood is unavailable.

Freeze-dried plasma: From damage control resuscitation to coronavirus disease 2019 therapy.

BACKGROUND: Freeze-dried plasma (FDP) is a promising blood component for prehospital resuscitation given its logistic advantages over fresh frozen plasma (FFP). COVID-19 convalescent (CC) plasma has been used to treat coronavirus disease 2019 (COVID-19) patients, and its corresponding FDP has potential use during future pandemics. Therefore, we conducted the study to determine if the hemostatic and immunological properties of plasma can be retained after lyophilization. STUDY DESIGN AND METHODS: Hemostatic tests were conducted with Rotational Thromboelastometry (ROTEM) and a Stago analyzer. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG (Immunoglobulin G) and neutralizing activity were analyzed using Meso Scale Diagnostics immunoassay kits. RESULTS: There were no differences in ROTEM parameters and Stago measurements for prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen and D-dimer concentrations, and antithrombin, factor V, VIII, and protein S activities between FFP and FDP for either pre-COVID-19 or CC samples. Differences were observed in INTEM clotting time and PT and PTT when comparing reconstituted FDP stored at 4°C for 24 h or room temperature for 4 h to healthy control. Both CC-FFP and CC-FDP showed two orders of magnitude higher concentrations of IgG antibodies against SARS-CoV-2 antigens than pre-COVID-19-FFP and pre-COVID-19-FDP and healthy control. Similarly, the CC samples showed approximately 4-fold higher %-inhibition of receptor binding than the pre-COVID-19 samples. There were no differences in either the antibody levels or neutralization activity between CC-FFP and CC-FDP. DISCUSSION: We demonstrated that FDP and CC-FDP retained the same hemostatic and antibody functional activities relative to their initial plasma sources, supporting clinical evaluation of their benefits in severe trauma and COVID-19 patients.

Finger cold-induced vasodilation test does not predict subsequent cold injuries: A lesson from the 2018 Canadian Forces Exercise.

A cold-induced vasodilation (CIVD) test was administered to 113 Canadian Armed Forces (CAF) soldiers (age 25.6 ± 6 yrs) during pre-deployment to a Canadian Arctic training exercise. The incidence and rates/types of subsequent peripheral cold injuries, as well as the relationship of CIVD responses against other hypothesized/reported risk factors (smoking, gender, age, ethnicity and prior cold injury), were analyzed. Although there was a wide range of CIVD RIF (resistance index to frostbite) scores (mean = 5.0 ± 1.5), there were no systematic relationships between RIF and injury type/location and rate, and the other risk factors analyzed. The absence of physiological links to cold injury occurrence suggests that in a military cold deployment setting, other factors are in play, which might include clothing, training, leadership and doctrine. These factors should be examined in future work.