Fluid Shifts in Space Flight Analogues and Terrestrial Wound Clinic Applications by woundmasterclass

December 2023

Fluid Shifts in Space Flight Analogues and Terrestrial Wound Clinic Applications Editorial Summary In space, astronauts experience fluid shifts from their legs to their upper body, causing symptoms like head fullness and vision changes known as Spaceflight Associated Neuroocular Syndrome (SANS). NASA researchers are studying SANS using analog tests that simulate space conditions. They use noninvasive imaging techniques to monitor fluid shifts and develop countermeasures. These techniques could also be useful in improving wound care by diagnosing lymphatic dysfunction and edema. NASA's research in nutrition and other areas can benefit healthcare. By adopting advanced technologies, similar to the James Webb telescope, wound clinics can achieve better outcomes.

Introduction

S Dr M. Mark Melin

Dr Heather Barnhart

Medical Director of the M Health Wound Healing Institute

Professor, Dept of Physical Therapy, Nova Southeastern University

Adjunct Associate Professor, University of Minnesota Surgical Department Mineapolis MN, United States

Fort Lauderdale FL, United States

pace travel poses unique challenges for astronauts, including significant fluid shifts from the legs to the upper body, leading to symptoms such as head ‘fullness’ and altered vision. This condition, known as Spaceflight Associated Neuroocular Syndrome (SANS), is a priority area of research for NASA as they plan future missions to the moon and Mars. Earthbased studies use space flight analogue testing to simulate these fluid shifts, but real-time imaging of fluid shifts in a head-down position has been lacking. Recent advancements in noninvasive imaging techniques have shown promise in monitoring fluid shifts and understanding SANS. Additionally, these imaging technologies hold potential for improving diagnostics and treatments in wound care, particularly for conditions like venous leg ulcerations and lymphedema. By applying lessons learned from space research, we can explore innovative approaches and enhance patient outcomes in wound care.

Fluid Shifts in Low Earth Orbit (LEO) Entering Low Earth Orbit (LEO) induces a significant fluid shift in astronauts, where approximately 2 litres of fluid move from the legs to the upper torso, neck, and head. This fluid shift occurs within the first 24 hours in LEO and is followed by human physiology adaptation over the following 7 days. However, the resolution of fluid shifts varies, and complete improvement is not always achieved.

Mr Frank Aviles

Ms Sabrina Ginsburg

Wound Care Clinical Coordinator, Natchitoches Regional Medical Center

University of Miami Miller School of Medicine HPSP Student

Natchitoches LA, United States

Lake Worth, Florida, United States

Wound Masterclass - Vol 2 - December 2023

Symptoms of Spaceflight Associated Neuroocular Syndrome (SANS) Astronauts in space experience various symptoms associated with Spaceflight Associated Neuroocular Syndrome (SANS). These symptoms include a sense of ‘fullness’ in the head, stuffy nose, and altered taste sensation. Furthermore, approximately 40 - 70% of the crew develops varying symptoms of SANS. The syndrome leads to ocular, retinal, and vision changes, retinal nerve thickening, and alterations in fluid distribution within the

Fluid Shifts in Space Flight Analogues and Terrestrial Wound Clinic Applications

“By providing valuable insights into fluid distribution associated with different body positions (head down vs. supine vs. sitting up), noninvasive imaging techniques can contribute to improved diagnosis, treatment, and prevention of SANS."

brain, including cerebrospinal fluid shifts.

Recent Head Down Tilt Analogue Study

Causes and Priorities for Investigating SANS

Our team recently conducted a head-down tilt spaceflight analogue study to examine fluid shifts in volunteers. In this study, we utilized long wave infrared thermography, Near-Infrared Spectroscopy (NIRS), and a subcutaneous edema monitor. These imaging techniques are current standard options in wound clinics and readily available for point-of-care diagnostics.

The cause of SANS is hypothesized to be multifactorial, involving factors such as genetics, altered micronutrient pathways, elevated CO2 exposure on the International Space Station, increased radiation exposure, and alterations in androgen hormones. Currently, there are no fully effective countermeasures for SANS. As astronauts plan future ventures to the moon's surface and long-duration spaceflights to Mars, the investigation of SANS and the development of reliable treatments have become among the highest priorities for NASA researchers.

Space Flight Analogue Inducing Fluid Shifts

Testing

and

To understand the causes and effects of fluid shifts in space, researchers perform Earth-based research using volunteers involved in space flight analogue testing. One type of analogue testing involves placing volunteers on a bed with a 6-degree head-down tilt to simulate fluid shifts from the legs to the torso, head, and neck, mimicking certain aspects of being in LEO. It is important to note that this analogue testing does not replicate ‘true weightlessness' experienced by astronauts in spaceflight. Nonetheless, it is a validated model capable of inducing symptoms of SANS.

Potential of Noninvasive Imaging for Fluid Shift Monitoring and Countermeasure Development The utilization of validated noninvasive imaging devices holds promise in monitoring fluid shift patterns in real-time. These devices can assist in further understanding the dynamics of fluid shifts and contribute to the development of countermeasures for SANS. By providing valuable insights into fluid distribution associated with different body positions (head down vs. supine vs. sitting up), noninvasive imaging techniques can contribute to improved diagnosis, treatment, and prevention of SANS. Figure 1: Body lymphatics.

Limitations of Current Analogue Testing Methods Although analogue testing can induce symptoms of SANS, there is a limitation when it comes to real-time noninvasive imaging of the fluid shifts accompanying the head-down position. To date, such imaging has not been completed, presenting a gap in understanding the dynamics of fluid shifts during simulated space conditions.

Wound Masterclass - Vol 2 - December 2023

Fluid Shifts in Space Flight Analogues and Terrestrial Wound Clinic Applications

“Embracing noninvasive imaging technologies represents a paradigm shift in wound care, providing clinicians with valuable insights into the comprehensive pathophysiology of wounds and enabling targeted interventions for optimal patient care.”

Significance of Gravity-Induced Fluid Shifts in Wound Care In the field of wound care, we encounter patients daily who experience significant fluid shifts influenced by the constant pull of gravity. Conditions such as venous leg ulcerations (VLU), lymphedema associated with VLUs, lymphatic dysfunction in diabetics with foot ulcerations, and other lower extremity chronic wound pathologies, are affected by these fluid shifts. Recognizing the impact of gravity, we emphasize the importance of consistent compression and leg elevation management to improve leg wound outcomes.

Improving Diagnostics for Lymphatic Dysfunction and Edema The potential of noninvasive imaging techniques such as longwave infrared thermography, NIRS, and subcutaneous edema monitors can be harnessed to enhance diagnostics in cases of lymphatic dysfunction and edema associated with leg ulcerations. Lymphedema and resulting diffuse edema significantly compromise lower extremity wound healing and increase wound recidivism rates. However, clinical recognition of lymphedema remains poorly acknowledged in most wound and vein centers, which compromises patient outcomes. By utilizing the entire spectrum of ‘light' beyond human Figure 2: NASA space station.

visible wavelengths, these noninvasive imaging techniques offer a promising approach to improve the recognition and understanding of the underlying pathophysiology, supporting advanced research and enhanced treatments in common wound clinic pathologies.

The Role of Noninvasive Imaging in Enhancing Wound Care Outcomes Noninvasive imaging devices hold great potential as point-of-care tools in wound clinics. By allowing for the recognition and early treatment of lymphatic dysfunction associated with living on Earth in a ‘1G' environment, as well as monitoring fluid shifts to the lowest points of the body, these devices can significantly improve wound care outcomes. Embracing noninvasive imaging technologies represents a paradigm shift in wound care, providing clinicians with valuable insights into the comprehensive pathophysiology of wounds and enabling targeted interventions for optimal patient care.

Healthcare Spinoffs and NASA Research NASA's extensive research efforts have resulted in numerous ‘healthcare spinoffs' that have the potential to benefit the patients we serve. Areas such as nutrition and wound care management, often overlooked, have received considerable attention from NASA. These research endeavors provide valuable knowledge and insights that can be applied to improve healthcare outcomes.

Exploration of Wound Care Management in NASA Research Wound care management is one area where NASA research can contribute significantly. For those interested in delving deeper into the subject, NASA's publication on human adaptation to spaceflight and nutrition in 2021 offers a wealth of knowledge, showcasing the agency's commitment to advancing our

Wound Masterclass - Vol 2 - December 2023

Fluid Shifts in Space Flight Analogues and Terrestrial Wound Clinic Applications

understanding of spaceflight human adaptive physiology and its implications for healthcare.

Embracing Technological Advances for Enhanced Patient Outcomes Similar to the paradigm shift brought about by the James Webb telescope in our understanding of celestial bodies, incorporating advanced technologies into wound clinics has the

potential to revolutionize treatments and outcomes for the patients we care for. By adopting and integrating ‘James Webb telescope' technology (referring metaphorically to noninvasive imaging devices) into wound clinics, we stand at the threshold of remarkable advancements in wound care. As we embrace these new possibilities, we position ourselves at the forefront of wound care advances, ready to propel patient outcomes to new heights.

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