Space is not kind to the human body. Astronauts are subjected to copious radiation, neurological feedback loops are altered and fluid shifts become readily apparent. Removal of a downward venous gradient over time is now thought to lead to intracranial hypertension with consequences resembling those of uncontrolled pseudotumor cerebri for long-duration space missions. Breathing circuits in the spacecraft must be managed to allow for adequate fresh gas flow and CO2 removal while still maintaining allowable engineering parameters. As experts in hemodynamics, breathing mechanics and gas exchange, anesthesiologists are uniquely qualified to understand and manage the complex changes occurring to the human body during spaceflight. These and new challenges will only become more apparent as human space exploration continues to expand and private companies begin offering commercial spaceflight.
Even healthy subjects experience profound fluid shifts and autonomic changes in spaceflight. Acutely, up to 2L of fluid shifts cranially, creating “chicken...
