Abstract and Introduction
Two months after landing on Mars, an astronaut suffers from a fall during an extravehicular activity, resulting in a fractured femur. Because it is impossible to return home, the remaining crew must manage the injury.
Imray et al. argued that modern day explorers will encounter "environments where physiologic and geographical extremes necessitate prompt and innovative approaches to rescue, medical care, and transportation." A human settlement in deep space perfectly illustrates this statement, particularly when considering the challenges of providing emergency medical and trauma care.
Experts have estimated that the most significant risks for space exploration missions are trauma, hemorrhagic shock, and infections.[2–4] To some extent, the likelihood of medical events can be estimated from analog ground populations, both military and civilian, and data gathered during human spaceflight experience.[2,5,6] For example, the risk of lower limb fracture has been estimated at 0.046 event per Mars mission (950-day mission for a crew of six). A recent consensus of experts estimated that such trauma would have one of the highest impacts on the mission (ranked fifth out of 30 severe medical conditions).
Moon exploration missions leading to the establishment of a permanent settlement are planned in the coming years, as early as 2024 (National Aeronautics and Space Administration [Washington, D.C.] NASA Artemis program), and will be followed by Mars missions. The private sector, spearheaded by the efforts of the company SpaceX (Hawthorne, California), is also shifting its focus from low-Earth orbit to the colonization of Mars, with the first manned missions planned for the mid-2020s. The duration, remoteness, and type of activities involved on a Moon or Mars settlement lead to hazard exposure different than would be expected in low Earth orbit.[6–8] Specifically, challenges of the unique lunar environment include exposure to reduced gravity (about one sixth of Earth's gravity on the Moon and one third on Mars), ionizing radiations, meteoroids, planetary dust, hypobaric decompression sickness, and extreme temperatures.[7–9]
The vast number of extravehicular activities planned during surface exploration will expose the astronauts to a high cumulative risk of traumatic accidents and hypobaric decompression sickness.[2,3,8,10] Exposure to weightlessness (and possibly even to partial gravity) reduces bone density to osteoporotic levels after a few months without countermeasures and exposes astronauts to an increased risk of pathologic fractures.[10–12]
In this focused narrative review, we sought to identify key challenges for a crew on the surface of Mars or the Moon facing a severe surgical emergency such as a major trauma. In particular, we examined the existing literature for factors related to medical evacuation, telemedicine, the delivery of anesthesia and surgery, and behavioral health and performance. Finally, we analyze what technologies and futuristic concepts could be useful in both the setting of a space mission and the practice of anesthesia on Earth.
Anesthesiology. 2021;135(1):155-163. © 2021 American Society of Anesthesiologists | Lippincott Williams & Wilkins