Bridging the gap between military prolonged field care monitoring and exploration spaceflight: The Compensatory Reserve
Technological challenges faced by military researchers to develop solutions for prolonged field care (PFC) are very similar to those faced by NASA in preparing for future missions.
The battlefield of the future will be a stark contrast to previous settings. Instead of well-developed theaters of war with rapid evacuation of casualties to a higher-level of care medical facility, combat medics must be prepared to support extended duration patient care in remote and austere environments. This is the concept of prolonged field care (PFC). With limited resources, significant distances to travel before definitive care, and an inability to evacuate in a timely fashion, medical care in space is the ultimate example of PFC. High-quality, real-time, and predictive monitoring -- being able to obtain necessary physiological data points to accurately assess patient status and guide decision making -- of casualties would address many of the gaps in PFC for the military and human exploration spaceflight. In this paper, we reviewed recent advances for clinical monitoring currently being studied under the US Army PFC directive. Specifically, we highlight the successful use of the compensatory reserve measurement (CRM) algorithm's sensitive and specific physiologic monitoring capability and how this technology can be translated to use in exploration spaceflight missions.
The standard traditional clinical approach to assessing patient status has relied heavily on measures of vital signs, however, these tend to stay in normal or near normal ranges during the compensatory phases and provide little information for specific early diagnosis. New innovative technology to assess patient status should provide early, sensitive, and specific indicators of impending physiological compromise. Because physiological compensation is highly individualized, these technologies must also distinguish between various individual responses to better inform accurate medical decision making (i.e., precision medicine). CRM represents a new paradigm that measures the sum total of all mechanisms that compensate for relative blood volume deficit to allow for early recognition of physiological compromise earlier than the development of clinical symptoms. CRM provides a metric of the integrated compensatory mechanisms that together protect against low tissue perfusion during states of inadequate or compromised delivery of oxygen (DO2) and serves to prevent reaching critical DO2 by assessing real-time alterations in the arterial waveform. Developed to monitor combat casualties, CRM has been tested under many conditions that may arise in future PFC settings. This paper highlights the successful use of CRM to assess patient status in conditions of hemorrhage, hyperthermia, dehydration, physical exertion, trauma, and sepsis and how these results are relevant and important for future exploration spaceflight missions as well.
We invite you to read more to learn about our technology in the complete article found here: https://www.nature.com/articles/s41526-019-0089-9