Intravenous Solutions for Exploration Missions

*† ‡ § This paper describes the intravenous (IV) fluids requirements being developed for medical care during NASA’s future exploration class missions. Previous research on IV solution generation and mixing in space is summarized. The current exploration bas eline mission profiles are introduced, potential medical conditions described and evaluated for fluidic needs, and operational issues assessed. We briefly introduce potential methods for generating IV fluids in microgravity. Conclusions on the recommended fluid volume requirements are presented. I. Introduction The Vision for Space Exploration outlined a new direction for NASA, consisting of missions unlike those accomplished before. These missions will return astronauts to the Moon and test the technologies required for Mars missions. The International Space Station (ISS) will be used as a test bed for some of these new technologies. NASA’s Exploration Systems Architecture Study presents the Design Reference Missions (DRMs) that are being used to facilitat e the derivation of requirements for the essential technologies. These DRMs include missions to ISS, Lunar Sorties, Lunar Outposts, and Mars Exploration. 1 These longer duration missions increase the likelihood of a medical incident and thus the need for m edical fluids. The Patient Condition DataBase (PCDB) contains a list of over 400 medical conditions that may present and require treatment during ISS missions. 2 These conditions are a subset of the total possible conditions that could be encountered durin g long duration, Extra -Vehicular Activity (EVA) intensive, exploration missions. Of the 442 conditions, approximately 115 may require medical fluids during the course of treatment. Terrestrial treatment would typically include fluids such as Normal Salin e (NS) (0.9% NaCl), 5% Dextrose, Lactated Ringer’s, or whole blood. Operational constraints, such as mass limitations and lack of refrigeration, may limit the type and volume of such fluids that can be carried onboard the spacecraft. Representative condi tions that would require fluid treatment include major bone fracture, burns, and acute anemia. These conditions are described in detail later in this paper. Choosing a technology to generate sterile water for injection and produce intravenous fluids requi res balancing capabilities with mission and medical requirements. For example, the type, volume, and timeline over which IV fluids are required are key drivers in selecting an appropriate technology. Additionally, the system must operate in various gravi ty environments, such as microgravity, lunar gravity, and Martian gravity, while also functioning in earth normal gravity for testing and verification. Thrusting events also produce an effective gravitational level and could possibly occur during fluid pr oduction. Successful operation requires maintaining sterility. Some technologies might be sealed until use, requiring only seal integrity, while other systems may require internal recirculation or periodic maintenance to ensure proper operation. Diagnos tics will likely be required to verify proper operation of the system. Crew time is always an issue, and may be especially important in an emergency. Any system must be relatively simple to use, safe, and reliable.