2024.07.06-Space Medicine_Stern.pdf

 Space Medicine Claudia Stern 06/07/2024 The ESAM ACADEMY 2  Effects of microgravity on the human body Fluid shift Space Adaptation Syndrome Muscle atrophy Bone loss Renal stones Exposure to ionizing radiation Space associated n...

 Space Medicine Claudia Stern 06/07/2024 The ESAM ACADEMY 2  Effects of microgravity on the human body Fluid shift Space Adaptation Syndrome Muscle atrophy Bone loss Renal stones Exposure to ionizing radiation Space associated neuro-ocular Syndrome Back pain Fluid Shift Shift of up to 2.0 litre of fluid from lower to upper body within minutes of entry into microgravity Barosensors in the big vessels notice an oversupply of blood and excrete a hormon that the kidneys induce to excrete fluids Blood volume is reduced Mucosae of nose and throat swell Bird legs Stedy state within 3-5 days  Space Adaptation Syndrome 2/3 of all astronauts are affected Headache, nausea, dizziness > 1/3 suffer from vomiting Duration: 2 - 3 days „Mismatch“ between the sensation of the body posture and the visual sense Muscle loss Muscles of the legs and the back are affected During short term missions: Musle loss 10-20% During long term missions: Musle loss 40-50%, loss of musle strength: 20-50% The heart as a musle is also affected Body changes in microgravity Bone and muscle loss Calcium excretion: possibility of renal stones 2.5 hours sport activities per day ©ESA/NASA Muscles were stimulated by an electric suit ©NASA  Bone loss If no (musle) stress is put on the muscles the density and bone mass is reduced through absorption About 1-2 % per month in microgravity Seems to be not reversible in all astronauts Absorption stopps only 4 weeks after the landing Rebuilding can take up to 24 months Depends very much on the training discipline of the astronaut Bones follow musles Bone resorption promotes stone formation (lithiasis) Bone resorption releases calcium Is excreted by the kidneys Can produce kidney stones Risk of radiation exposure Acute: Nausea Vomiting Death Longterm: Cataract Infertility Cancer Potential Outcome: Sickness and reduced performance Reduced life expectancy during and after the mission Radiation Measurements Crew Passive Dosimeters (each crew member carries a radiation detector for the whole duration of the mission) Matroshka: Torso: 68 kg, 1,1 m height, 60 cm diameter Within the ISS and EVA at the ISS Contains human bones active und passive radiation detectors at > 800 positiones Radiation Measurements Radiation measurement and evaluation of Both mannequins are made of materials protection vest AstroRad that mimic the bones, soft tissues and organs of adult women, so that the radiation dose can be measured in the organs that are particularly sensitive to radiation Credit: DLR Spaceflight associated neuro-ocular Syndrome (SANS) Rumors about changes of vision in space are as old as spaceflight Some astronauts reported about an improvement in vision, others about a reduction in vision  In 2008 first known case of visual changes after long duration space flight Visual Impairment and Intracranial Pressure (VIIP) Syndrome 7 cases were reported Since then about 40% (15 cases) of astronauts coming back from a long duration spaceflight (~ 6 months) have been identified with VIIP Syndrome Eye Changes Posterior globe flattening Hyperopic shift Optic disc edema Reduced Visual Acuity Choroidal folds Indications of increases intracerebral pressure Cotton Wool Spots -(Visual field defect) Optic Disc Edema © NASA Longitudinal Study of Astronaut Health Choroidal folds © NASA Longitudinal Study of Astronaut Health Simulation of microgravity 30-60 days -6° head down tilt Research facility :envihab ©DLR VaPER (VIIP and Psychological :envihab Research Study) Professional astronauts  84 Testpersons (age average 50,4 years) Hypertension (27) Cardiac Deseases (15) Diabetes (10) Pulmonary Deseases (14) Back problems (29) Controlls (24) Highest Blood Pressure: 217/144 mm Hg; HF 192 Hypoglycemia Hypotony Arhythmia (52%) Questionnaire Grayout: 69% Nausea: 20% Neck problems: 6%  2 Diabetes patients with insulin pump Expectable problems: Hypo/hyperglycemia, pump damage, unexpected stress response RR, ECG, oxygen saturation, questionnaire concerning nausea, gray out No problems, no abnormalties Blood sugar stayed between 110-206 mg/dl 06/07/2024 The ESAM ACADEMY 23 06/07/2024 The ESAM ACADEMY 24 06/07/2024 The ESAM ACADEMY 25 06/07/2024 The ESAM ACADEMY 26 Medical Screening in Commercial Spaceflight What are the additional challenges? Acceleration and deceleration forces Motion sickness Weightlessness Hypoxia Pressure difference Small and possibly crowded cabin Noise Extraordinary psychological situation Medical evaluation procedure Standardisation and mutual acceptance Medical assessment for professional pilots Step I: Questionnaire Step II: Physical evaluation Step III: Training Step IV: Preflight evaluation Step V: Check out  Medical evaluation step I: Questionnaire Check for potential no-go criteria (high risk of sudden emergency) Can be performed by the respective candidate, help of family doctor Helps to find out potential health problems Medical evaluation step I: Questionnaire Additional specific questions History of decompression sickness (DCS) Diabetes Cancer Heart or circulatory disorders (including implanted pacemaker or defibrillator) Disability or deformity requiring accommodation Mental disorders Claustrophobia Vertigo Seizures Questionnaire: Medication We know a lot of potential side effects of medication Sedation (Sleepiness) Vasodilatation (Blood pressure) Bradycardia Psychtropic effects …… But we do not always exactly know how much all the taken medication influences each other The individual medical evaluation and the relevance for the flight profile is a challenge for the medical examiner Medical evaluation step II: Physical Evaluation Physical Examination Laboratory tests (BC, Lipid profile, Urinanalysis) Electrocardiogram Ophthalmology (Visual acuity, Refraction,Tonometry) ENT, Hearing (speech discrimination, pure tone audiometry on indication) Pulmonary function testing Medical evaluation step II: Physical Evaluation Cardiovascular stress test Abdominal ultrasound over 65 years Tilt table testing to prevent/detect reasonable vasovagal or orthostatic reactions during flight Re-evaluation Following EASA Class 2 5 years up to 40 years 2 years 40-50 years 1 year thereafter  Step IV: Preflight evaluation Interval between initial medical assessment 7 to 14 days before take - off phone conversation with possible advice Anamnestic changes in medical situation (Medication, Infection, Surgery) At the Spaceport before the flight Basic physical examination Resting ECG Blood pressure Urine Pregnancy test Step V: Check out Questionnaire Blood pressure ECG Differences in recommendations of examinations AsMA, International Academy of Aeronautics, FAA, International Association for the Advancement of Space Safety (IAASS) Historical und cultural differences Discrimination versus aptitude Suborbital Flights and competencies in Europe No legal definition of air and space Suborbital: aviation or space activity ESA: technical organization and not a regulating body that has the legislative power EU: competencies of EU and member states “co-exists” Member states may only exercise its competencies if the EU does not make use of its competencies Suborbital Flights and competencies in Europe EASA´s mandate does not cover space activities Member states issue Air Operator Certificates (AOC) EASA has oversight Certification entails responsibility FAA issues licenses Leaves the responsibility to the operator High potential exposure to liability will probably not lead to a transitional regime of EASA Tanja Masson-Zwaan: Regulation of sub-orbital space tourism in Europe. Air and Space Law35 no.3 (2010)263-272 Conclusion: Recommendations for a safe and unforgettable trip The beginning of commercial spaceflight contains unknown risk factors to the respective passengers There are almost no experiences with laymen in space Medical evaluation, selection and training are necessary to execute safe suborbital spaceflight We recommend high standards for the screening procedure in the initial phase of commercial human spaceflight The medical certification procedure should be standardized and there should be mutual acceptance between the testing centers The standards might be lowered with successful flights and more data