Performance of far forward iceless blood storage containers in controlled cold environments.

BACKGROUND: The Golden Hour Box (GHB), an iceless blood container designed for transfusion closest to the point of injury, is used by military medical teams in remote damage control resuscitation. While its performance is well-established in hot environments, it remains underexplored in cold conditions, a significant consideration in emerging global conflict zones. STUDY DESIGN AND METHODS: Four GHBs were preconditioned at +4°C or +18°C for 8 h and subsequently exposed to controlled laboratory simulated temperatures of -5, -15, and -25°C for 100 h. The study focused on their capability to maintain an internal temperature between +2 and +6°C, the recommended range for red blood cells unit storage and transport, using calibrated sensors for precise monitoring. RESULTS: When exposed to negative Celsius temperatures, GHBs showed varied performance depending on preconditioning temperatures. When preconditioned at +4°C, GHBs maintained an internal temperature within the target range (+2 to +6°C) for 100 h at -5°C, 52 ± 1 h at -15°C, and 29 ± 4 h at -25°C. In contrast, the internal temperature of GHBs preconditioned at +18°C exceeded this range in less than 30 min, then dropped below 2°C more rapidly than those preconditioned at +4°C, occurring within 20 ± 2 h at -15 and 13 ± 1 h at -25°C. CONCLUSION: The GHB, when properly preconditioned, effectively maintains internal temperatures suitable for blood product transport in extreme cold. Future research, including analyses of blood performances, is still needed to validate these results in more realistic operational conditions for use in cold environments.

COVID-19 Repeated Convalescent Plasma Collection: Analysis of 149 Donations from 88 French Military Health Workers.

BACKGROUND: Passive therapy with convalescent plasma (CP) could be an effective and safe treatment option in COVID-19 patients. Neutralizing antibodies present in CP generated in response to SARS-CoV-2 infection and directed against the receptor-binding domain of the spike protein are considered to play a major role in the viral clearance. CP infusion may also contribute to the modulation of the immune response through its immunomodulatory effect. We describe for the first time the effectiveness of a CP collection protocol from repeated donations in young patients. MATERIALS AND METHODS: We enrolled health service workers who experienced mild to moderate COVID-19 and from whom several donations have been collected. No minimal severity threshold and no biological cure criteria were required. Donors could return to a second plasma donation 14 days after the first donation. A minimal neutralizing antibody titer of 1:40 was considered for clinical use. RESULTS: Eighty-eight donors were included (median age 35 [28-48] years, 41 women), and 149 plasma products were collected. COVID-19 were mainly WHO stage 2 infections (96%). Among the 88 first donations, 76% had neutralizing antibody titers higher than or equal to 1:40. Eighty-eight percent of donors who came for a second donation had a neutralizing antibody titer of 1:40. Median durations were 15 (15-19) and 38 (33-46) days from the first to the second donation and from recovery to the second donation, respectively. Sixty-nine percent of donors who came for a third donation had a neutralizing antibody titer of 1:40. Median durations were 16 (13-37) and 54 (49-61) days from the second to the third donation and from recovery to the third donation, respectively. No significant difference was observed between the IgG ratio and the age of the donors or the time between recovery and donation. The average IgG ratio did not significantly vary between donations. When focused on repeated blood donors, no significant differences were observed either. CONCLUSION: The recruitment of young patients with a mild to moderate CO-VID-19 course is an efficient possibility to collect CP with a satisfactory level of neutralizing antibodies. Repeated donations are a well-tolerated and effective way of CP collection.

Air-drop blood supply in the French Army.

BACKGROUND: Haemorrhagic shock remains the leading cause of preventable death in overseas and austere settings. Transfusion of blood components is critical in the management of this kind of injury. For French naval and ground military units, this supply often takes too long considering the short shelf-life of red blood cell concentrates (RBCs) and the limited duration of transport in cooling containers (five to six days). Air-drop supply could be an alternative to overcome these difficulties on the condition that air-drop does not cause damage to blood units. METHODS: After a period of study and technical development of packaging, four air-drops at medium and high altitudes were performed with an aircraft of the French Air Force. After this, one air-drop was carried out at medium altitude with 10 RBCs and 10 French lyophilised plasma (FLYP). A second air-drop was performed with a soldier carrying one FLYP unit at 12 000 feet. For these air-drops real blood products were used, and quality control testing and temperature monitoring were performed. RESULTS: The temperatures inside the containers were within the normal ranges. Visual inspection indicated that transfusion packaging and dumped products did not undergo deterioration. The quality control data on RBCs and FLYP, including haemostasis, suggested no difference before and after air-drop. DISCUSSION: The operational implementation of the air-drop of blood products seems to be one of the solutions for the supply of blood products in military austere settings or far forward on battlefield, allowing safe and early transfusion.