understood that it was important to have blood available to wounded troops. Around 1918–still during WWI–the American Expeditionary force routinely performed transfusions in its hospitals using citrated blood (blood treated with sodium citrate or citric acid to prevent its coagulation), developed because of the difficulty in storing whole blood and keeping it from going bad. In mid-1941, just before the U.S. entered WWII, the Subcommittee on Blood Substitutes had been contemplating what would be the best and safest methods of storage and delivery of blood and plasma for the purpose of transfusions. It was decided that frozen plasma would be superior to dried or liquid plasma because it was “simple, economical, and easy to preserve.”
The only thing that the Subcommittee saw as being a potential problem was the transportation of the frozen plasma and the prevention of thawing. It would take some time before refrigerated shipping containers were developed to meet the storage and temperature requirements necessary to properly preserve blood and plasma during transport. This eventually came to form in what was called the “Army Container.” Developed in the mid-1940’s, these insulated shipping boxes were made of double-cardboard and insulated with aluminum foil and cotton batting. The Army Container was almost six cubic feet in size and was fitted to hold about forty-eight 600-cc bottles of blood. It also had a compartment that could hold up to 19 pounds of ice. Flash forward about 65 years. Today we have “cold chain distribution,” a system where state-of-the-art temperature controlled packaging is part of a supply chain which supports effective refrigerated transport around the globe. Shippers and producers have made great advances in the act of keeping everything from blood to medicines frozen or refrigerated while in transit. The AX150L Mobile Refrigerator and the RKN Air Cargo Thermal Pallet Shipper, both by AcuTemp, are examples of modern-day, cutting-edge cold storage technology. Originally targeted for military use, the AX150L is the latest in the line of active systems produced by AcuTemp (former products include the AX27L VaxiCool and AX56L HemaCool) and was developed to meet U.S. Marine Corps specifications. Precise temperatures on this unit can be set between +2°C (35.6°F) and +30°C (86°F). The RKN is meant for larger pallet-sized loads of temperature-sensitive products and can be programmed for temperatures ranging from +4°C (39.2°F) to +25°C (+77°F). Both of these units use the very latest in insulation technology and can be powered from multiple sources found throughout the world, including solar with the AX150L.
The technology behind maintaining precise temperature requirements under varying conditions for long periods of time continues to advance and evolve. While “passive” coolants like dry ice are still in use today, companies that rely on refrigerated shipping containers to transport sensitive goods are moving away from the negative impacts and instability of passive cooling methods, and are instead moving toward “actively” compressor driven containers such as the AX150L and the RKN. With remote data logging capabilities, the new actively powered units are quickly becoming the first choice for military and civilian applications. The recent advances in cold chain distribution technology and temperature controlled packaging are game-changing. We’ve certainly come a long way from having to shovel ice into a crude cardboard and aluminum box.