Emergency Medicine IS Out Of This World Dr Alicia Tucker Emergency Physician Diving and Hyperbaric Medicine Fellow Royal Hobart Hospital Disclosures ❖ I am not a Flight Surgeon ❖ I do not represent the Australian Space Agency ❖ I am not an Astronaut …..But I’d like to do all three!! Mission Objectives ❖ Introduction ❖ Challenges of Human Spaceflight ❖ Challenges of Medical Care Delivery in Space ❖ Exploration Medical Capability ❖ From Astronaut to Physician ❖ From Emergency Physician to Astronaut?? Why Hobart? ❖ Australian Antarctic Division/CARMM ❖ University of Tasmania/CARMM ❖ Royal Hobart Hospital ❖ Triple Lock Hypobaric/Hyperbaric Chamber Graduate Certificate in Healthcare in Remote and Extreme Environments (M5A) “Houston, we have a problem……” Challenges of Human Spaceflight ❖ Gravity and Weightlessness ❖ Vacuum/Pressure ❖ Radiation ❖ Temperature Extremes ❖ Micrometeoroids and Space Debris ❖ Isolated, Confined, Extreme Environment (ICE) ❖ Distance from Earth** Acceleration Forces - Launch and Re-entry ❖ Its all about Rocket Science! ❖ Rotational Speed of Earth = 460m/s ❖ Escape Velocity = 11.2km/s (Mars = 5.027km/s) ❖ To get to the moon = 14.5km/s ❖ On Launch body experiences 3-4G ❖ Re-entry –Shuttle (1.5G), Soyuz (4.5G), Ballistic Entry (8G) ❖ Highest risk of Loss of Crew Life ❖ Cost to send 1kg to Space = $20 000! Gravity and Weightlessness Weight = mass x gravity Weightlessness ≠ No Gravity Every small body, independent of its mass orbits with the same speed at the same distance around a big body. Eg ISS 27 500km/hr Weightless is like free fall (zero-G/micro-G) The Effect of Weightlessness on Humans 1. Fluid Redistribution ❖ Within moments of being in micro-g ❖ Puffy moon face, sinus and nasal congestion, fatigue, anorexia, constipation ❖ Adaptation – reduced plasma volume around 20% (‘Micro-G Normal’) ❖ Altered cardiac function – ‘becomes lazy’; reduced autonomic responses ❖ Orthostatic hypotension and syncope on return to earth The Effect of Weightlessness on Humans 2. Space Adaptation Syndrome/Space Motion Sickness ❖ >50% affected ❖ Lose of proprioceptive signals ❖ Lack of gravitational effect on otoliths ❖ Motion sickness – nausea, vomiting, vertigo, ❖ headaches, lethargy ❖ Takes up to 72hrs to adapt, often need help ❖ from medications The Effect of Weightlessness on Humans 3. Space-flight Associated Neuro-ocular Syndrome (SANS) ❖ Previously known as Vision Impairment and Intracranial Pressure (VIIP) ❖ 23 percent of short-flight and 49 percent of long-flight astronauts ❖ Cause not confirmed: ❖ ?fluid shift , ?increased CO2 ❖ ?increased sodium intake ❖ ?homocysteine metabolism The Effect of Weightlessness on Humans 4. Bone and muscle deterioration ❖ 1.5-3% loss of bone mass/month eg lower vertebrae, hip and femur due to increased osteoclast activity ❖ Increased calcium in blood – increased calcinuria and increased kidney stones ❖ Increased spinal length/height up to 7cm! Back Pain. ❖ Rapid muscle atrophy within a week ; 4-6 month mission = 20% loss upper limbs, 50% lower limbs, 50% paraspinals! ❖ Recovery time is 2-2.5 x mission length. Trabecular pattern may differ. ❖ Risk Mitigate: ❖ Resistive Exercise devices and treadmills ❖ Nutrition: Vit D, fish meals, more calorie load, reduced sodium Vacuum/Pressure Excursions ❖ Vacuum – a space void of matter ❖ Space is close to, but not a perfect vacuum ❖ Stars, planets, and moons keep their atmospheres by gravitational attraction, and as such, atmospheres have no clearly delineated boundary. ❖ The density of atmospheric gas decreases with distance from the object. Vacuum/Pressure Excursions ❖ Earth at sea level – ‘1 atm’ ( 760mmHg) ❖ Mount Everest – 1/3 atm (250mmHg) ❖ 100km altitude – 3 x 10 -7 atm ❖ ISS (400km) – 10-11 atm ❖ Interstellar – 10-20 atm Armstrong Limit/Line (18900m)- is the altitude that produces an ambient pressure so low (0.0618 atmosphere or 6.3 kPa (47 mmHg)) that water boils at the normal temperature of the human body: 37 °C (98.6 °F) The Effect of Vacuum on Humans ❖ Ebullism – The formation of gas bubbles in bodily fluids due to reduced environmental pressure. Body fluids boil! Steam swells tissues. Skin/spacesuits prevent rupture ❖ Hypoxia – within 10 seconds there is removal of all gases from the lungs, so lose consciousness. Death from hypoxia within 1-2 minutes ❖ Decompression/Barotrauma – ambient pressure changes: ❖ Barotrauma: pulmonary, middle ear, inner ear, sinus ❖ Decompression Illness: CAGE, DCS – ‘The Bends/The Chokes’ Radiation ❖ The Earths atmosphere and magnetosphere helps protect us from radiation. Mars has no global magnetic field ❖ Van Allen Belts and South Atlantic Anomaly ❖ 1 year in Low Earth Orbit = 10 x Earth ❖ Types: ❖ Galactic cosmic rays ❖ Solar Particles ❖ Trapped Particles Temperature Extremes ❖ Coldest Temperature on Earth -88C (Vostock Station Antarctica) ❖ Hottest Temperature on Earth 58C (Libyan Desert) ❖ Temperature outside ISS (-157C to 120C) ❖ Temperature on Mercury (-180 to 420C) ❖ Temperature on Mars (-125 to 20C) ❖ Temperature on Neptune (-220 to -200C) ❖ Absolute Zero – 273.15C ISS Environmental Control and Life Support System (ECLSS) Micrometeoroids and Space Debris Micrometeoroids ❖ Constantly degrade casing of spacecraft. ❖ Can damage shields/antennae. Space Debris ❖ Manmade, left over launchers, satellites; ❖ Over 300000 pieces >1cm in orbit Mitigation ❖ Risk analysis ❖ Shields ❖ Collision Avoidance Manoeuvres ❖ Space Clean up ICE - Psychological Effects of Space "If you want to instigate the art of manslaughter just shut two men up in a eighteen by twenty-foot cabin for a month. Human nature won't stand it.“ ❖ Antarctic over-winter teams: ❖ 12% psychological adaptation difficulties, ❖ 3% Full psychological disorders ❖ 14% US Mir Astronauts experienced depression ❖ Analogues: Mars500, Mars160, HiSEAS, HERA A Typical Astronaut! - Equivalent to ASA class III ❖ Hypovolaemic/Orthostatic – reduced intravascular and extracellular volume (10-20%) ❖ Anaemic – reduced EPO, increased red cell destruction by spleen (Hb down 15%) ❖ Osteopaenic – 1.5-3% total body calcium loss/month ❖ Weak and aerobically deconditioned – Loss of muscle mass; VO2 Max down 15% ❖ Reduced Vision – altered depth of field and acuity ❖ Electrolytes – reduced ADH and diuresis - Na+ lower by 6%; Aldosterone increased so increased K+ excretion; low Mg++; Increased arrhythmias (PVCs, SVT, AF) ❖ Ventilation/perfusion zones abolished – increased perfusion and decreased ventilation ❖ Immunosuppressed – increased cortisol, reduced IL-1; increased neutrophils, other cell lines reduced; altered microbiologic flora ❖ Altered wound healing ❖ Psychologically fragile Factors Affecting The Level of Care in Space ❖ The type of mission, length of stay, extravehicular activities (EVAs), and mission objectives. ❖ The number, health and performance of the crew upon embarking on the mission. ❖ Risk of illness or injury. ❖ Mission/Programmatic philosophy of accepted medical risk (Crew Health Concept of Operations and IMM). • Factors Affecting The Level of Care in Space ❖ Fixed Supplies. ❖ The level of training of the medical provider. ❖ Environment in which initial assessment and management is completed ❖ Some technology and advances in medicine can’t be utilised in this austere environment. ❖ The distance from the platform to more definitive care, either Earth or Gateway. Limited return capability. Diagnostics in Space ❖ Diagnostic Resources are limited ❖ The major skill set is most likely offsite or not available ❖ Adaptive physiology will alter presenting signs and symptoms ❖ Microgravity – affects distribution of pathological fluid and gas eg FAST ❖ Loud ambient noise effects auscultation Therapeutics in Space Therapeutic resources are limited ❖ Launch mass, power, telemetry all in short supply ❖ Dedicated Crew Medical Officer may have only 60 hours of medical training Nearest Trauma Centre ❖ Flight surgeons direct the team via video link off site Micro-gravity ❖ No passive air-fluid separation - can’t just hang an IV ❖ Restraints required for patient, clinician and equipment ❖ Bleeding – large fluid domes tend to adhere to wound but can also contaminate cabin atmosphere ❖ Pharmaceuticals work differently ❖ Reduced gastric emptying ❖ Evidence of reduced biological activity Therapeutics in Space Procedures possible in micro-G (with adaptations) ❖ Ventilation ❖ IV infusion ❖ Laceration closure ❖ Percutaneous Tracheostomy ❖ Foley catheter drainage ❖ Chest drain insertion and drainage ❖ Laparotomies (on animals only so far) ❖ Auto-transfusion from haemo-thorax ❖ Peritoneal lavage…NOT SO MUCH! Interim Mission Report ❖ Introduction ❖ Challenges of Human Spaceflight ❖ Factors affecting the level of medical care in Space Case Scenario – Astronaut with Right Sided Back Pain Issues: Differential Diagnosis: ❖ Differential Diagnosis ❖ Musculoskeletal back pain ❖ Decompression Illness ❖ Assessment ❖ Do you cut short the EVA? ❖ Renal Calculus ❖ ❖ Management Pyelonephritis ❖ Retrocaecal appendicitis ❖ Disposition.