aviation medicine

Aviation Medicine 

Definition

Also known as aerospace medicine, flight medicine, or space medicine, aviation medicine is a medical specialty that focuses on the physical and psychological conditions associated with flying and space travel.

Purpose

Since flying airplanes and spacecraft involves great risk and physical demands, such as changes in gravity and oxygen, pilots and astronauts need medical experts to protect their safety and the public's safety.

Description

Pressure changes

In the United States, the Federal Aviation Administration (FAA) requires all pilots who fly above 14,500 ft (4,420 m) to be prepared for pressure changes caused by lower oxygen levels at high altitude. Pilots must either have a pressurized cabin or access to an oxygen mask. Without these protections, they could experience hypoxia, or altitude sickness. Hypoxia reduces the amount of oxygen in the brain, causing such symptoms as dizziness, shortness of breath, and mental confusion. These symptoms could cause the pilot to lose control of the plane. Hypoxia can be treated with oxygen therapy.

Rapid altitude increases and decreases can cause pain because there is an air pocket in the middle portion of the ear. To equalize pressure in the ear, physicians typically advise pilots and passengers to clear their sinuses by plugging their nose and blowing until the eardrums "pop." Other options include yawning, swallowing or chewing gum. For people with a cold or a severely blocked middle ear, the use of decongestants, antihistamines, or nasal sprays may help. Without taking steps to equalize pressure, the tympanic membrane could rupture, causing hearing loss, vertigo, dizziness, and nausea.

Gravity's impact

Fighter pilots who fly high-performance jets can experience health problems during rapid acceleration and when executing tight turns at high speed. During these moves, a pilot experiences extreme gravity conditions that can pull blood away from the brain and heart and into the lower body. This can cause the pilot to have tunnel vision or pass out. To prevent these potentially deadly situations, the military requires fighter pilots to wear special flight suits, or G suits, which have compartments that fill with air or fluid to keep blood from pooling in the lower body.

Some pilots, like the Blue Angels, use a technique called the Valsalva Maneuver instead of G suits to prevent black outs during high-performance flying. The Valsalva Maneuver involves grunting and tightening the abdominal muscles to stop blood from collecting in the wrong parts of the body.

PREVENTIVE CARE. Since any routine health problem that affects a pilot could mean the loss of hundreds of lives, aviation medicine specialists who work for commercial airlines and the military take special care to educate pilots about proper diet, exercise and preventive health tools. For example, physicians may frequently screen pilots for vision changes caused by glaucoma or cataracts. They also will check for hearing loss and encourage the pilot to wear earplugs or headphones to buffer engine noise. To monitor for heart disease, physicians will check blood pressure and may order diagnostic tests such as an ECG or stress test.

Motion sickness

Many people experience nausea, vertigo, and disorientation when they first arrive in space. This is caused by changes in the fluid in the inner ear, which is sensitive to gravity and affects our sense of spatial orientation. The symptoms typically ease after several days, but often recur when the astronaut returns to Earth. To treat this condition, physicians give astronauts motion sickness medication, such as lorazepam.

Key terms

G suits — Special flight suits, worn by fighter pilots, which have compartments that fill with air or fluid to keep blood from pooling in the lower body during rapid acceleration and tight turns.

Hypoxia — Hypoxia, or altitude sickness, reduces the amount of oxygen in the brain causing such symptoms as dizziness, shortness of breath, and mental confusion.

Tympanic membrane — A structure in the middle ear that can rupture if pressure in the ear is not equalized during airplane ascents and descents.

Valsalva Maneuver — Pilots grunt and tighten their abdominal muscles to prevent black outs during high-performance flying.

Bone and muscle loss

In zero-gravity conditions, astronauts lose bone and muscle mass. On earth, the natural resistance of gravity helps build stronger muscles and bones during normal weight-bearing activities like walking or even sitting at a desk. In space, however, astronauts must work harder to prevent bone and muscle loss. Exercise is an important treatment. Crew members may use an exercise cycle or resistive rubber bands to stay in shape. Physicians also may give them medication to prevent bone loss and prescribe nutritional supplements, such as a mixture of essential amino acids and carbohydrates, to limit muscle atrophy.

Radiation

Another health threat to space travelers is radiation. Harmful rays can alter the DNA in human cells and cause cancer. Excess radiation also can weaken the immune system. To prevent these problems, physicians may give astronauts nutritional supplements. For example, research has show that n-3 fatty acids found in fish oil reduce DNA damage.

Cardiovascular issues

When astronauts return to earth after a long mission, they tend to feel dizzy and black out. Scientists are concerned about this dilemma because it could be dangerous if the crew members need to make an emergency exit. One way to prevent this problem, which is caused by a drop in blood pressure, is to have the astronauts drink extra fluids and increase salt intake to increase blood volume. Physicians also may prescribe medication that causes blood vessels to contract. As another precaution, astronauts also put on protective flight suits, or G suits, before they re-enter the earth's atmosphere.

Resources

Periodicals

Aviation, Space and Environmental Medicine. Monthly peerreviewed journal published by the Aerospace Medical Association. Contact theeditor: 3212 Swandale Dr., San Antonio, TX 78230-4404. (210) 342-5670. ASEMJournal@worldnet.att.net.

Organizations

Aerospace Medical Association. 320 S. Henry St., Alexandria, VA 22314-3579. (703) 739-2240. http://www.asma.org.

National Space Biomedical Research Institute. One Baylor Plaza, NA-425, Houston, TX 77030. (713) 798-7412. info@www.nsbri.org. http://www.nsbri.org.

Wright State University Aerospace Medicine Program. P.O. Box 92, Dayton, Ohio 45401-0927. (937) 276-8338. http://www.med.wright.edu.

Other

Federal Aviation Administration Office of Aviation Medicine. 〈http://www.faa.gov/avr/aamhome.htm〉.

National Aeronautics and Space Administration Aerospace Medicine. 〈http://spacelink.msfc.nasa.gov〉.

Society of USAF Flight Surgeons Online Catalog. 〈http://www.sam.brooks.af.mil/ram/rammain.htm〉.

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medicine /med·i·cine/ (med´ĭ-sin)

1. any drug or remedy.

2. the diagnosis and treatment of disease and the maintenance of health.

3. the treatment of disease by nonsurgical means.

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alternative medicine  see complementary and alternative medicine.

aviation medicine  that dealing with the physiologic, medical, psychologic, and epidemiologic problems involved in aviation.

Chinese herbal medicine  a highly complex system of diagnosis and treatment using medicinal herbs, one of the branches of traditional Chinese medicine. Herbs range from the nontoxic and rejuvenating, used to support the body's healing system, to highly toxic ones, used to treat disease.

clinical medicine 

1. the study of disease by direct examination of the living patient.

2. the last two years of the usual curriculum in a medical college.

complementary medicine , complementary and alternative medicine (CAM) a large and diverse set of systems of diagnosis, treatment, and prevention based on philosophies and techniques other than those used in conventional Western medicine. Such practices may be described as alternative, existing as a body separate from and as a replacement for conventional Western medicine, or complementary, used in addition to conventional Western practice. CAM is characterized by its focus on the whole person as a unique individual, on the energy of the body and its influence on health and disease, on the healing power of nature and the mobilization of the body's own resources to heal itself, and on the treatment of the underlying causes, not symptoms, of disease. Many of the techniques used are controversial and have not been validated by controlled studies.

emergency medicine  the medical specialty dealing with the acutely ill or injured who require immediate medical treatment.

environmental medicine  that dealing with the effects of the environment on humans, including rapid population growth, water and air pollution, travel, etc.

experimental medicine  the study of diseases based on experimentation in animals.

family medicine  see under practice.

folk medicine  the use of home remedies and procedures as handed down by tradition.

forensic medicine  medical jurisprudence.

geographic medicine 

1. geomedicine.

2. tropical m.

group medicine  the practice of medicine by a group of physicians, usually representing various specialties, who are associated together for the cooperative diagnosis, treatment, and prevention of disease.

herbal medicine  herbalism.

holistic medicine  a system of medicine which considers man as an integrated whole, or as a functioning unit.

internal medicine  that dealing especially with diagnosis and medical treatment of diseases and disorders of internal structures of the body.

legal medicine  medical jurisprudence.

mind-body medicine  a holistic approach to medicine that takes into account the effect of the mind on physical processes, including the effects of psychosocial stressors and conditioning, particularly as they affect the immune system.

naturopathic medicine  naturopathy.

nuclear medicine  the branch of medicine concerned with the use of radionuclides in the diagnosis and treatment of disease.

occupational medicine  the branch of medicine dealing with the study, prevention, and treatment of workplace-related injuries and occupational diseases.

orthomolecular medicine  a system for the prevention and treatment of disease based on the theory that each person's biochemical environment is genetically determined and individually specific. Therapy involves supplementation with substances naturally present in the body (e.g., vitamins, minerals, trace elements, amino acids) in individually optimized amounts.

patent medicine  a drug or remedy protected by a trademark, available without a prescription; formerly used for quack remedies sold by peddlers.

physical medicine  physiatry.

preclinical medicine 

1. preventive m.

2. the first two years of the usual curriculum in a medical college.

preventive medicine  science aimed at preventing disease.

proprietary medicine  a remedy whose formula is owned exclusively by the manufacturer and which is marketed usually under a name registered as a trademark.

psychosomatic medicine  the study of the interactions between psychological processes and physiological states.

rehabilitation medicine  the branch of physiatry concerned with the restoration of form and function after injury or illness.

socialized medicine  a system of medical care controlled by the government.

space medicine  the branch of aviation medicine concerned with conditions encountered by humans in space.

sports medicine  the branch of medicine concerned with injuries sustained in athletics, including their prevention, diagnosis, and treatment.

traditional Chinese medicine  (TCM) the diverse body of medical theory and practice that has evolved in China, comprising four branches: acupuncture and moxibustion, herbal medicine, qi gong, and tui na. In all of these, the body and mind are considered together as a dynamic system subject to cycles of change and affected by the environment, and emphasis is on supporting the body's self-healing ability. Fundamental to TCM are the yin and the concept of basic substances that pervade the body: qi, jing, and shen, collectively known as the three treasures, and the blood (a fluid and material manifestation of qi) and body fluids (which moisten and lubricate the body).

travel medicine , travelers' medicine the subspecialty of tropical medicine consisting of the diagnosis and treatment or prevention of diseases of travelers.

tropical medicine  the branch of medicine concerned with diseases of the tropics and subtropics.

veterinary medicine  the diagnosis and treatment of diseases of animals other than humans.

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aviation medicine

[āv′ē·ā′shən]

a branch of medicine that is concerned with the health effects of travel by aircraft, including such aspects as jetlag, restricted body movement for long periods, and reaction to violent aircraft movement in turbulent weather. See also aerospace medicine, aviation physiology.

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aviation medicine

Travel medicine In-flight emergencies Federal Aviation Agency regulations require that an 'enhanced' medical kit–stethoscope, sphygmomanometer, airway tube, syringes, epinephrine, nitroglycerin, 50 ml 50% dextrose, diphenhydramine injectable be carried on any airplane with > 30 seats In-flight emergencies Syncope 29%, cardiac/chest pain 16%, asthma/shortness of breath 10%, allergic reactions 5%, in-flight deaths Disease transmission Resurgence of TB has made the aerosol transmission through aircraft ventilation systems a health hazard of unknown epidemiologic significance  Statistics 0.31 deaths/106 passengers—regardless of flight length; 125 deaths/109 passenger kilometers; 25 deaths/106 departures; the average victim was ♂, age 53.8, physicians were available in 43% of cases Cause of death Cardiac 56%, terminal cancer 8%, respiratory 6%, miscellaneous and no cause, the remainder. See Traveler medicine.