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Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.
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Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Mar 26, 2015

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Page 1: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Space Medicine

Biological Hazards and Medical Care in Space

H.G. Stratmann, M.D.

Page 2: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Vostok Launch

Page 3: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Mercury-Atlas 3 Liftoff

Page 4: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Gemini 12 Liftoff

Page 5: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Apollo 11 Launch

Page 6: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Astronaut on Moon

Page 7: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Skylab

Page 8: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Apollo-Soyuz Apollo capsule

Page 9: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Apollo-Soyuz Soyuz capsule

Page 10: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.
Page 11: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Mir

Page 12: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Earth from Moon

Page 13: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Terrestrial versus Extraterrestrial Environment

Earth LEO Moon Mars

Atmosphere 78% Nitrogen21% Oxygen

~ None None 95% CO2

3% nitrogen2% argon

Pressure 760 mmHg ~ None None ~ 5 mmHg

Temperature(Celsius)

21o -178o to + 110o ~ same as LEO -120o to +25o

Gravity (g) 1.0 ~ None 0.16 0.38

Radiation(rems/year)

0.1 to 0.2 ~ 14.0-21.0 ~ 20.0 ~ 15.0

Page 14: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Major Biological Risks of Space Travel

• Loss of atmosphere• Exposure to toxins• Mechanical trauma• Acceleration and deceleration• Extreme temperatures• Meteoroids and space debris• Circadian rhythms and sleep• Psychological• Adverse biological effects of microgravity• Radiation

Page 15: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Loss of Atmosphere• Barotrauma

– Expansion of gas temporarily trapped in a body cavity (e.g. ear or sinus)

– Pressure differences causing pain or injury• Decompression sickness

– Ambient atmosphere pressure < partial pressure of inert gases (e.g. nitrogen)

– Nitrogen forms bubbles in bloodstream• “Bends” (pains in joints and muscles)• “Chokes” (gas emboli)• Neurological symptoms (weakness,

convulsions, syncope)

Page 16: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Loss of Atmosphere

• Explosive decompression– Rate of decompression is so great that transient

overpressure occurs in lungs and other air-filled cavities

– Pressure difference in the lungs ≥ 80 mm Hg causes rupture and possible air embolism

– Ebullism - “boiling” of body fluids (e.g. blood)• At body core temperature of 37o C, ebullism

occurs at an ambient pressure of 47 mm Hg (Armstrong limit, roughly an altitude of 19 kilometers)

Page 17: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Loss of Atmosphere

• Ambient pressure/atmosphere in Space Shuttle is similar to sea level on Earth (14.7 psi, 78% nitrogen, 21% oxygen)

• Extravehicular activity (EVA) requires space suit pressure of 4.3 psi

• To prepare for EVA, cabin pressure is slowly lowered (maximum 0.1 psi/sec) to 10.2 psi for 24 hours

• Astronauts don space suits and prebreathe 100% oxygen to purge nitrogen from the blood, then undergo final decompression to 4.3 psi

Page 18: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Toxins

• Ammonia– Used in Shuttle environmental control and life-

support systems– Causes irritation of eyes and mucous membranes– More severe exposure causes dyspnea, vomiting,

and pulmonary edema• Freon

– Used in the heat exchange system– Can produce lightheadedness, dyspnea, liver

damage, and arrhythmias

Page 19: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Toxins

• Hydrazine and monomethyl hydrazine– Use in Shuttle auxillary power unit– Cause severe burns, liver and kidney damage,

and seizures in liquid and gaseous forms• Nitrogen tetroxide

– Used as oxidant in Orbital Maneuvering System– Causes burns and blindness in liquid form and

pneumonitis and pulmonary edema when inhaled (Apollo-Soyuz, 1975)

Page 20: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Trauma and Mechanical Failure

• Astronauts are vulnerable to conventional injuries– Burns– Abrasions– Lacerations– Electrical shock– Fractures– Deliberately inflicted injuries

Page 21: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Space Fatalities

• Soyuz 1 (1967)—1 fatality when parachute system failed during reentry

• Soyuz 11 (1971)—3 fatalities due to sudden depressurization during reentry

• STS-51L (1986)—7 fatalities due to failure in booster rockets

• STS-107 (2003)—7 fatalities during reentry due to damage to left wing

Page 22: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Challenger Explosion

Page 23: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Columbia Launch

Page 24: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Acceleration and Deceleration

• Excessive g (an acceleration of 9.8 m/s2) can cause lightheadedness or syncope

• Upper limit of 4 g for sustained long-term acceleration and (briefly) 18 g for control of movement

• Mercury program—up to 8 g briefly during launch and up to 11 g during reentry– “The Right Stuff”

• Shuttle—3 g during launch, 1.2 to 1.4 g during reentry

Page 25: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Temperature Control

• Heat exchange in space is based solely on radiation, either from the Sun or to space itself—not by conduction or convection

• Effective temperature-control systems are available for both space suits and spacecraft

Page 26: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Meteoroids and Space Debris

• Represent a risk of collision with spacecraft or astronauts during EVA

• Meteoroids consist of stone and iron, with a total of 200 kg within 200 km of Earth’s surface at any given time

• Average velocity of meteoroids is about 16 km/sec

• Most are ≤ 0.1 mm in diameter, but can be ≥ 1 cm

Page 27: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Meteoroids and Space Debris

• Over 3 million kg of man-made debris (old rocket boosters, destroyed satellites, flecks of pain or particles of rocket fuel) are within 2000 km of Earth’s surface

• Over 7000 objects > 20 cm in size are tracked by NORAD

• Collision velocity with an orbiting spacecraft would be about 10 to 13 km/sec

• Range in size from < 0.1 mm to meters

Page 28: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Circadian Rhythms and Sleep

• Body rhythms that occur over a period of about 24 hours

• Sleep/activity cycle, body temperature, heart rate and blood pressure, secretion of growth hormone, cortisol, melatonin, etc.

• Entrained on cyclical environmental stimuli, especially the light-dark cycle based on Earth’s 24-hour rotation

Page 29: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Circadian Rhythms and Sleep

• Rapid travel through different time zones on the Earth’s surface disrupts the synchronization between endogenous biological “clocks” and external cues like light/darkness

• The resulting desynchronosis (“jet lag”) is associated with insomnia, loss of appetite, and fatigue

• Light-dark cycles in space vary widely• Light-dark cycle in low Earth orbit is between 80 to

140 minutes, 30-40% of which is darkness

Page 30: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Circadian Rhythms and Sleep

• Sleep disturbances are common in astronauts– Insomnia– Intermittent, poor quality, or even

prolonged (up to 12 hours) sleep– Sleep disturbances can degrade work

performance and alertness during routine or emergency situations

– Half of Shuttle astronauts use sleeping medications

Page 31: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Psychosocial Stressors of Space Flight

• Isolation, loss of social contacts, reduced sensory stimulation, anxiety, boredom, loss of privacy, dealing with emergencies, overly busy work schedules

• Decreasing motivation, emotional hypersensitivity and lability, and irritability or hostility toward Earth-bound control personnel and crewmates occur during extended missions (e.g. Skylab, Mir, ISS)

Page 32: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Radiation

• Serious hazard for acute and long-term injury during prolonged space missions

• Sun produces electromagnetic (gamma rays and X-rays) and particulate (electrons and protons) radiation

Page 33: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Radiation

• Solar radiation is produced continuously (solar wind) and increases dramatically during solar particle events (high energy protons of 10 to 500 MeV)

• Cosmic radiation is a constant source of radiation, consisting of very high energy protons (up to 2 GeV), alpha particles, and heavier ions originating outside the Solar System (possibly from old supernovas)

Page 34: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Radiation

• Surface of Earth is protected by:– Atmosphere (e.g. ultraviolet light, X-rays,

and gamma rays)– Van Allen Belts

• Two ring-shaped regions at average altitudes of 1000 to 10,000 km and 13,000 to 20,000 km where extraterrestrial electrons and protons are trapped by Earth’s magnetic field

• Lower belt descends to about 500 km at the “South Atlantic anomaly,” where the most radiation exposure in low Earth orbit occurs

Page 35: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Radiation

• Average annual radiation exposure at sea level is 0.1 to 0.2 rem

• Average annual radiation exposure in low Earth orbit (366-day Mir mission) was up to 14 to 21 rem

• EVA and solar events (particularly solar particle events associated with coronal mass ejections) increase radiation exposure– Could expose an astronaut to potential level dose of

hundreds of rem• Proper shielding of spacecraft and use of underground

habitats on lunar and Martian missions would dramatically decrease radiation exposure

Page 36: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Risks of Radiation Exposure

• Acute effects of whole-body exposure– Prodromal syndrome (50 to 150 rem)– Hematopoietic syndrome (150 to 400 rem)– Hematopoietic-gastrointestinal syndrome (400 to

800 rem)– Gastrointestinal syndrome (800 to 2000 rem)– CNS syndrome (>2000 rem)

• LD50 is about 400 rem

Page 37: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Risks of Radiation Exposure

• Long-term effects– Cataracts– Infertility– Defects in offspring– Malignancy

• Breast• Thyroid• Leukemia• Lung

Page 38: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Biological Effects of Micro and Low gravity

• Neurovestibular

• Cardiovascular

• Hematological

• Musculoskeletal

Page 39: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityNeurovestibular

• Space Adaptation Syndrome– Occurs in 2/3 of astronauts (males > females)– Headache, nausea, vomiting, dizziness, malaise– Made worse by head and body movements– Develops shortly after entering orbit, peaks after 1

to 2 days, and usually resolves after 4 to 7 days– Responds fairly well to dimenhydrinate,

promethazine, and other motion sickness medications

Page 40: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityNeurovestibular

• Sensory illusions (e.g. “inversion illusion”)• Postflight problems

– Feeling “levitated” over bed when trying to sleep at night

– Ataxic gait and walking straight when trying to turn a corner

– Feeling extraordinarily heavy or that one is being pushed to one side while only standing

– May take weeks or months to resolve

Page 41: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityCardiovascular

• Shift of 1.5 to 2.0 L of fluid from lower to upper body within minutes of entry into microgravity from loss of gravity-induced hydrostatic pressure– Jugular venous distention– Facial puffiness, nasal congestion, headaches,

nasal voice– Reduction of calf diameters by 30% (“bird legs”)– Enlargement of liver and other visceral organs

Page 42: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityCardiovascular

• Decreased sympathetic tone– Can cause orthostatic hypotension and syncope

on return to Earth, particularly when coupled with redistribution of at least 1 L of reduced total body fluid volume to lower extremities

– Heart size and mass decrease slightly– Variable, relatively mild changes in heart rate,

blood pressure, and left ventricular systolic function

– Minor arrhythmias

Page 43: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityHematological

• Red blood cell counts decrease by 10 to 20% of preflight values within 2 to 3 weeks in space, then slowly recover after about 60 days– May represent increased destruction and

decreased production of RBCs

• Spherocytes and echinocytes increase

Page 44: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityHematological

• Neutrophil counts increase an average of 32%– May be due to stress-induced release of

epinephrine and glucocorticoids

• Killer T-lymphocytes show diminished number and activity

• Little change in helper T-lymphocytes or B-lymphocytes

• Eosinophils decrease by an average of 62% of pre-flight values

Page 45: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityMusculoskeletal

• Relaxed astronauts in microgravity assume a fetal position, with loss of normal curve of the thoracolumbar spine

• Increase in height of 3 to 6 cm from decompression of intervertebral disks, with possible associated pressure on nerve roots and back pain

Page 46: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityMusculoskeletal

• Decrease in muscle mass (primarily in weight-bearing muscles of legs and back)– Vigorous exercise programs (up to 3 hours per

day) using isotonic and isometric exercises help stabilize muscle mass at 80 to 85% of preflight value

– Muscle weakness and soreness postflight, with gradual return of preflight muscle mass after weeks to months of exercise

Page 47: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityMusculoskeletal

• Microgravity causes demineralization of bone, decreased total bone mass, and increased urinary and fecal calcium loss (greater risk of urolithiasis)

• Mechanism for bone loss is not established– Activity of osteoclasts unchanged– Activity of osteoblasts decreased

Page 48: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityMusculoskeletal

• With exercise programs, total bone mass loss is similar to muscle loss (about 15 to 20% of preflight values)– Percentage of bone loss is greater in

weight-bearing bones (e.g. calcaneus)– Bone mass may not return to preflight

value even years later

Page 49: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityCountermeasures to microgravity

• Vigorous exercise programs– Treadmill– Rowing machine– Ergometer– Isometric exercise is more effective than isotonic

(aerobic) exercise for reducing bone and (probably) muscle loss

– Effectiveness of supplemental calcium or medications (calcitonin or clodronate) for controlling calcium loss hasn’t been established

– “Penguin” suit

Page 50: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityCountermeasures to microgravity

• Postflight orthostatic hypotension– Ingestion of salt tablets and 1 L of water

shortly before reentry– Lower-body negative-pressure devices

• Chibas suit

– G-suit

Page 51: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

MicrogravityCountermeasures to microgravity

• Artificial gravity– Rotation of spacecraft or habitat– Tethered system– Centrifuge for intermittent use

• Adverse effects of reduced gravity should be milder on Mars (0.38g) and the Moon (0.16g)

Page 52: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Care of Astronauts

• Preflight screening• Medical requirements for Shuttle crews

vary– Pilot (Class I)– Mission Specialist (Class II)– Payload Specialist (Class III)– Space Flight Participant (Class IV)

Page 53: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Care of Astronauts

• Requirements are most stringent for Class I (pilot)– Near vision better than 20/20 in each eye

(uncorrected) and either far vision 20/100 or better uncorrected, or correctable to 20/20 each eye

– BP no greater than 140/90 mmHg– Height between 64 inches and 76 inches

Page 54: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Care of Astronauts

• Requirements for Class II (mission specialist)– Distance visual acuity: 20/200 or better

uncorrected, correctable to 20/20 each eye– Blood pressure no greater than 140/90

mmHg measured in a sitting position– Height between 58.5 and 76 inches.

Page 55: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Care of Astronauts

• Class III and IV have no limit on near vision and BP must be no greater than 150/90 mmHg

Page 56: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Evaluation of Astronaut Candidates

• Medical history and physical examination• Cardiopulmonary tests

– Pulmonary function tests– Exercise treadmill test– Echocardiogram– EKG and 24-hour Holter monitor

• Eye and ear examination– Audiometry, visual acuity, color perception,

tonometry

Page 57: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Evaluation of Astronaut Candidates

• Dental examination• Neurological examination (including EEG)• Psychiatric interview and psychological tests• Tests

– X-rays of chest, sinuses, and teeth– Abdominal ultrasound– Mammogram in women

Page 58: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Evaluation of Astronaut Candidates

• Laboratory tests– Chemistries, blood counts, screens for STDs– Urinalysis– 24-hour excretion of calcium– Stool for ova and parasites– Drug screen– PPD– Pregnancy test (premenopausal women)

Page 59: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Care of Astronauts

• Medical examinations are done 10 days, 2 days, and immediately before a Shuttle launch

• Crew members live in restricted quarters for a week prior to launch to minimize exposure to infectious diseases

Page 60: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Care of Astronauts

• Two members of every Shuttle crew are assigned as medical officers– Non-physicians receive paramedic-level training– Advice during flight is available from ground-based

Crew Surgeon and Deputy Crew Surgeon

• All crew members receive 16 hours of lectures on the physiological effects of space flight and are trained in CPR and first aid

Page 61: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Injuries and illnesses during space flight

• Space Adaptation Syndrome• Nasal/sinus congestion• Headache• Backache• Skin irritation/dryness/dermatitis• Boils• Urinary tract infection• Renal colic• Prostatitis

Page 62: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Injuries and illnesses during space flight

• Upper respiratory infection (“cold”)• Pneumonitis• Minor abrasions/lacerations• Constipation• Arrhythmias• Decompression sickness• Corneal abrasion/foreign body• Musculoskeletal strain/sprain• Minor trauma/contusions

Page 63: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Supplies on Shuttle Missions and the ISS

• Medications– Analgesic and NSAIDs– Antiemetics

– Antihistamines and H1 blockers

– CNS stimulants– Cardiovascular agents

Page 64: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Supplies on Shuttle Missions and the ISS

• Medications– Antibiotics– Sedative-hypnotics– Antidepressants– Gastrointestinal agents– Dermatological agents– Ophthalmic and otic agents

Page 65: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Supplies on Shuttle Missions

• Diagnostic equipment and supplies– Blood pressure cuff and sphygmomanometer– Stethoscope– Disposable thermometers– Otoscope– Ophthalmoscope– Fluorescein strips

Page 66: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Supplies on Shuttle Missions

• Therapeutic items and other supplies– Needles– Syringes and tourniquet– IV tubing and normal saline– Suture equipment and supplies– Scalpels and scissors– Alcohol and betadine wipes, bandaids, gauze,

bandages, sponges– Surgical masks and gloves– Oral airway and cricothyroidotomy set

Page 67: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Medical Supplies on Shuttle Missions

• A defibrillator is not carried on most Shuttle flights

• A ventilator and X-ray equipment are not carried on Shuttle flights

• A defibrillator and an ultrasound system are carried on the International Space Station

Page 68: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Nutritional Factors

• Food intake of at least 2500 to 3000 calories/day– Negative nitrogen balance

• Fluid intake up to 4200 ml/day (e.g. from fuel cells)• Changes in sensitivity to taste and odors• Food on Shuttle includes thermostabilized,

rehydratable, intermediate-moisture, and natural-form items– Prepackaged for each crew member and stored in dry form

when possible– Forced-air convection oven for heating foods

Page 69: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Infection Control

• Personal hygiene is difficult in microgravity• Contamination by microorganisms from food, water

(especially if recycled), wastes, experimental animals, and payload items

• Microorganisms continuously shed from skin, mucous membranes, and GI and respiratory tracts– Released as aerosols by sneezing, coughing, and talking– Droplets do not settle but remain suspended until striking a

surface or coming into contact with a crewmember (e.g. inhalation)

– Increased bacterial resistance to antibiotics and reduced immune function

Page 70: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Problems with Medical Care in Space

• Limited equipment and supplies

• Limited expertise and medications

• Adverse effects of microgravity

Page 71: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Problems with Medical Care in Microgravity

• Direct effects on the body– Relative anemia– Increased susceptibility to and delayed healing of

fractures

• Difficulties with diagnostic and therapeutic procedures– No rising of air or layering of fluid on X-rays– No air-fluid levels in bowel obstruction– Placing patient in Trendelenburg position (e.g.

hypovolemia) or reverse Trendelenburg (e.g. congestive heart failure) are ineffective

Page 72: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Problems with Medical and Surgical Care in Microgravity

• Space pharmacology– Timing of dosing and changes in

absorption and metabolism of medications are not established

– Limited types and supplies of medications

Page 73: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Problems with Medical and Surgical Care in Microgravity

• Surgery– All individuals involved (physician, nurse, patient)

must be restrained– Difficulty maintaining a sterile field

• Drapes must be secured• Special techniques for putting on surgical gowns and

gloves• Airborne particles don’t settle• Special equipment required for washing and disinfecting

surgical equipment

Page 74: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Problems with Medical and Surgical Care in Microgravity

• Surgery– Use of inhaled agents for general anesthesia is

dangerous in confined area of a spacecraft– Effectiveness of spinal anesthesia is at least partly

gravity-dependent– Spurting arteries produce blood droplets suspended

in air, and venous blood forms hemispheric domes– Abdominal viscera float out of the abdomen– IV fluids require a pressure pump– Collected urine and blood don’t settle to bottom of a

measuring container

Page 75: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

ISS

Page 76: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Mars

Page 77: Space Medicine Biological Hazards and Medical Care in Space H.G. Stratmann, M.D.

Spirit Rover