Medical Education for Exploration Class Missions NASA Aerospace Medicine Elective at the Kennedy Space Centre.

BACKGROUND OF AEROSPACE MEDICINE ELECTIVE

For over a decade, the Canadian Space Agency (CSA) has selected Canadian medical students & residents to attend NASA's prestigious Aerospace Medicine Elective at either the Kennedy Space Center (KSC) on the Space Coast in Florida or the Johnson Space Center (JSC) in Houston, Texas (1). Selected students have the privilege to learn from pioneers and leading experts in space life sciences about the physiologic adaptations that occur during space-flight as well as the preparations and medical support required for a Space Shuttle launch to the International Space Station (ISS).

INTRODUCTION

The spaceflight environment poses many challenges to astronauts. Understanding the effects of long duration space travel and how a crew medical officer (CMO) operates in this extreme environment was the focus of the research project. The knowledge and skills set for future CMOs as the endeavours to space exploration continue, and Canada's involvement in this initiative was further assessed in this project.

Physicians are often chosen to be astronauts; however, non-physicians are often the CMO on the ISS. Forty hours of CMO training occurs during the two-year period leading up to the actual mission and there is no protocol for maintaining medical skills during a long duration mission (2,3). Therefore, procedural skill decay will be an important issue worth considering for long duration space missions, and effective countermeasures should be developed for CMOs to manage arising medical events. Also, extensive equipment and supplies for the medical interventions cannot be provided due to the severe weight and volume constraints of spaceflight (4,5,6). Thus, risk management strategies dictate that only those situations that are the most severe, or the most easily diagnosed and treated will be anticipated and supplied.

The greatest medical concerns to a crew on an exploration class mission include (i) radiation exposure (ii) human behaviour and performance and (iii) physiologic alterations in the reduced gravitational environment (2,4,5). With the cancellation of the Constellation program, the current plan for NASA is to support the extension of the ISS through 2020. Thus, the ISS will serve as a platform for space life sciences research as well as preparation for future exploration class missions by increasing our understanding of space physiology (6,7).

The standard of care on the ISS is to support the crew 24/7 from Mission Control and to stabilize & transport an astronaut to Earth for definitive medical care (2). For future exploration class missions, however, the medical care system will need to be very autonomous and self-sufficient due to the communication delay and extremely long separation from definitive medical care. Furthermore, procedural skill decay will become a mission-threatening medical consideration, as the expected rate of a significant medical event extrapolated to a 2.5 year Mars mission involving 6 crew members is approximately 1 event/mission (8).

Current countermeasures for procedural skill decay include efficient and structured medical training design (9). Specifically, the educational experience can be enhanced by designing realistic simulations, also known as High-fidelity Environment Analog Training (HEAT) (10,11). Similar to flight simulators, medical simulation allows effective training and maintenance of skills, and has been successful in improving the training of physicians in safety critical environments including the Emergency Department, the Operating Room and the Intensive Care Unit (12,13). NASA has also developed a flight-ready human patient simulator that can operate in simulated microgravity (i.e. KC- 135) and potentially spaceflight (14,15,16).

The importance of simulation based learning is highlighted by the Dual process model which describes efficient reasoning and judgment as distinguishing crew characteristics in safety critical environments (17). Essentially, the model describes two cognitive systems for problem solving:

System 1: characterized by intuitive, rapid reasoning.

System 2: characterized by deliberate, careful reasoning.

Thus, simulation based learning allows the student to develop essential reasoning and judgment skills (i.e. develop System 2) while continued practice allows unfamiliar situations to become more automated and efficient (i.e. develop System 1). This allows advancement to more complex tasks once competence in basic skills has been shown.

Ideally, efficient training design mitigates human error and the risk of an adverse event to a safe and acceptable level. In aviation, it is accepted that errors and mistakes by crewmembers will occur in any flight and a non-blame approach to error is emphasized (18). By shifting the focus from blame to safety, the error is dealt with as any other threat to safety, and the best course of action is discussed in an open atmosphere to determine the most appropriate response to the new situation (19). This philosophy of error management has been formalized into simulation based training entitled Crew Resource Management. It was developed in the late 1970s when it was found that up to 70% of aviation accidents were due to crew issues including failure in communication, lack of situational awareness and poor error management (20). Similarly in medicine, communication issues have been implicated in 70% of perinatal deaths and injuries (21). Also, it was found that 30% of neonatal resuscitation steps are not performed or performed incorrectly. Certainly, check-lists can be a helpful memory aid in these safety critical environments, especially when all relevant human factors are not addressed (22).

Human factors engineering is the study of the interaction between humans and their working environment (20,23). More specifically, its goal is to understand how human limitations, capabilities, characteristics, behaviours and responses will affect performance in a given environment. Furthermore, the application of our understanding of human factors to the design of an intuitive system will minimize risk and optimize performance (24,25).

For example, telemedicine has been used in the design of a model for safe technology transfer to community surgeons in Southwestern Ontario, Canada (26). The study used a preceptor guided training schedule to meet minimum case requirements. The preceptor allowed progression from direct "scrubbed-in" supervision to "verbalonly" supervision and finally to telementoring only when competent skill and judgment was observed. The study demonstrated the feasibility of a training program for laparoscopic colon surgery that shortens hospital stays and ultimately improves patient outcomes.

Telemedicine can also be applied to space travel. A case in point is Just-In-Time telemedicine for ultrasound exam, as it provides a means to investigate a wide variety of conditions in remote & austere environments (27). For the ISS, the training design uses a pre-mission familiarization with the equipment followed by on-board CD-ROM based skill enhancement, as well as remote expert guidance for patient exam. This telemedicine training algorithm developed for spaceflight has also been used to rapidly train medical and nonmedical personnel to perform complex procedures (28). Furthermore, it has been used to confirm the diagnosis of High Altitude Pulmonary Edema (HAPE) in mountain climbers on Mount Everest (29).

CANADA'S INVOLVEMENT IN THE FUTURE OF SPACE EXPLORATI ON

A unique contribution Canada can make to future exploration class missions is to develop a remote medical training program for crew medical officers. This could be a niche sector for the Great White North as it offers a vast and largely uninhabited geographic area, harsh climate and established medical infrastructure necessary to support the training of future astronaut-physicians.

Thus, as the International Space Station nears completion, it demonstrates how teamwork and collaboration foster the motivation and determination to overcome even the greatest of obstacles. Ultimately, efforts to better our world will undoubtedly inspire the next generation of scientists and explorers to improve their world as well. No matter how large or small the contribution, all those involved with the international space exploration effort can be proud of their motives.