Aeromedical Factors

Question 1

4 types of hypoxia

Answer 1

1. Stagnant hypoxia
2. Histotoxic hypoxia
3. Hypemic hypoxia
4. Hypoxic hypoxia

Question 2

Stagnant hypoxia

Answer 2

• Oxygen deficiency caused by poor blood circulation

- caused by shock, low G’s, cold temps, the heart failing to pump blood, or constricted artery (leg falls asleep)

Question 3

Histotoxic hypoxia

Answer 3

• the inability of blood cells to effectively use oxygen

- can be caused by drugs or alcohol

Question 4

Hypemic hypoxia

Answer 4

• Inability of blood cells to carry enough oxygen
• deficiency in blood such as anemia or CO poisoning
• carbon monoxide poisoning: CO latches itself onto blood 200 times more easily then oxygen
• cigarette smoke saturates blood with CO as high as 80%

Question 5

Hypoxic hypoxia

Answer 5

• not enough oxygen available (altitude)
• most common among aviators
• prevent with oxygen masks

Question 6

Symptoms of hypoxia (FISHRIBL)

Answer 6

F- fatigue
I- impaired judgment
S- sense of well being 
H- headache or dizziness 
R- reaction time decreases
I- impaired vision
B- blue fingers or lips (cyanosis)
L- limp muscles/numbness or tingling

Question 7

Hypoxia prevention

Answer 7

• prevention is the best defense for hypoxia since it impairs judgment when experiencing the condition
  1. Physical fitness
  2. Nutritious diet
  3. Avoid alcohol and smoking
  4. Comfortable atmosphere, when body is comfortable it uses less oxygen

Question 8

Supplemental oxygen

Answer 8

1. No person may operate a civil aircraft:
   12500’ MSL put to and including 14000’ MSL
   - aircrew is provided w/O2
   - over 30 min crew must use O2
   Above 14000’ MSL
   - flight crew must use at all times
   Above 15000’ MSL
   - all occupants must be provided with O2
2. Per AIM 8-1-2
   - pilots are encouraged to use O2 above 10000’ during the day
   - over night 5000’

Question 9

Hyperventilation

Answer 9

1. Results of excessive loss of carbon dioxide from the body caused by emotional stress, fright, or pain
2. Carbon dioxide in the body
   - CO2 stimulates the respiratory system to stabilize breathing
   - when physically active, more O2 is inhaled, which produces more CO2. This stimulates the respiratory system to breath faster to expel the added CO2
3. The higher the rate of breathing w/o the need for increased O2 causes excessive loss of CO2
4. Unconsciousness may occur as the body tries to stabilize breathing rate

Question 10

Hyperventilation symptoms (FISHRIPM)

Answer 10

F- fatigue or drowsiness
I- impaired judgment
S- sense of well being
H- headache or dizziness
R- reaction time decreases
I- impaired vision
P- pale clammy skin
M- muscle spasms

Question 11

Hyperventilation prevention/treatment

Answer 11

• recovery is quick if breathing is controlled
• breath normally, focus on breathing
• breathing into a paper bag
• talk out loud- distracts them and forces them to breath

Question 12

Middl ear and sinus block

Answer 12

Ear pain is the result of a difference in pressure between the middle ear and environment

Question 13

Middle ear

Answer 13

1. During ascents, higher pressure in middle ear opens the Eustachian tube to equalize pressure
2. During descents, higher pressure from outside air may not allow Eustachian tube to open and equalize pressure
   - may be prevented by descending slowly and gradually
   - swallowing, yawning, chewing might not open tube
   - valsalva maneuver hold nose and mouth shut and forcibly exhale
   - colds, sore throats, and ear infections can prevent equalization and be painful

Question 14

Sinuses

Answer 14

1. Blocked passages and/or congestion may prevent equalization and be painful
2. Lack of equalization between nasal passages and sinuses
3. Inflammation of the sinuses from allergy or cold may trap air in sinus cavities
4. Congestion around nasal passages caused by allergies and colds
   - nasal sprays, decongestants, valsalva maneuver, and descending slowly may help to prevent this
5. Consult an AME before using any medication

Question 15

Spatial disorientation

Answer 15

1. Is a confusion between motion perceived by the peripheral vision and actual motion taking place
2. Incorrect mental image of position,attitude, or movement relative to what is really happening
3. Not knowing position in space caused by conflicting info between 3 senses:
   - visual: eyes
   - kinesthetic/somatosensory system- nerves, skin, sound, Gravity
   - vestibular sense- inner ear hairs that sense movement
4. Focus on instruments
5. At night, ground celestial lighting is required to help prevent spatial disorientation
6. Rain on the windshield in flight. Peripheral vision tells you that you are moving faster then you really are. As the rain quickly flows past the AC

Question 16

Hypoxia

Answer 16

1. Lack of oxygen. Occurs when the tissues in the body do not receive adequate oxygen

Question 17

Motion sickness

Answer 17

1. Vestibular disorientation: inner ear fluid keeps moving once you are stopped
   - gives the feeling of movement when there is none
2. Caused by severe and intense feeling of instability from overstimulation of the vestibular sense.
3. Causes by a constant stimulation of vestibular sense
4. Can occur even among the most experienced pilots
5. Commonly occurs among passengers who focus inside the aircraft

Question 18

Motion sickness symptoms

Answer 18

• general discomfort
• paleness
• nausea
• dizziness
• sweating
• vomiting

Question 19

Motion sickness prevention/treatment

Answer 19

• lean head back against headrest and relax (to cope with vertical motion)
• keep passengers informed of flight progress
• open vents to allow cool, fresh air into cabin
• focus outside aircraft look for traffic/landmarks
• Dramamine

Question 20

Carbon monoxide poisoning/symptoms/treatment

Answer 20

1. Occurs when CO2 attaches to the hemoglobin and prevents it from carrying O2 to the cells of the body
2. CO attaches itself 200 times more easily to blood then oxygen
3. Caused by exhaust leak (cabin heat)
   SYMPTOMS:
   - headache
   - drowsiness
   - dizziness
   TREATMENT:
   - turn off cabin heat
   - open vents/windows
   - use supplemental O2 if available

Question 21

Fatigue 2 general types/effects and hazards

Answer 21

1. Acute:
   - short term and normal occurrence of everyday living
   - brought on by excitement, strenuous activity, or lack of sleep
   - prevented by eating well, getting plenty of sleep, and exercising
2. Chronic:
   - brought by continuous high stress periods or prolonged untreated periods of acute fatigue
   - usually requires help from a doctor
   - prevented by properly correcting acute fatigue
3. Effects/hazards:
   - adverse effect on ability to make sound decisions
   - impaired coordination
   - degraded attention
   - adverse effect on ability to communicate

Question 22

Stress 3 types

Answer 22

The body’s response to physical and psychological demands placed on it

1. Physical
   - stress influenced by the environment such as temp, humidity, noise, vibration, or lack of O2
2. Physiological:
   - influenced by physical conditions such as fatigue, lack of exercise, sleep loss, hunger, and illness
3. Psychological:
   - influenced by emotional factors such as death of a loved one, sick child, relationship problems, work, or even winning the Lottery

Question 23

Categories of stress, effects, and stress management

Answer 23

1. Acute:
   - immediate threat “fight or flight”- short term
2. Chronic:
   - stress not dealt with, build up of acute stress
3. Effects:
   - inability to make effective decisions
   - poor judgment
   - increase risk of errors
4. Stress management:
   - avoid situations w/many distractions
   - organize cockpit before takeoff
   - stay calm in emergency
   - maintain proficiency in A/C
   - don’t let mistakes bug you

Question 24

Dehydration

Answer 24

Dehydration is a condition that occurs when the loss of body fluids, mostly water, exceeds the amount that is taken in. With dehydration, more water is moving out of your cells and bodies than what we take in through drinking

Question 25

Dehydration symptoms and corrective action

Answer 25

1. Symptoms:
   - rapid heart rate
   - increased thirst
   - dry mouth
   - tired or sleepy
   - decreased urine output
   - urine is low volume and more yellowish than normal
   - headache
   - dry skin
   - dizziness
   - few or no tears
2. Dehydration can worsen quickly requiring hospitalization
3. Corrective action:
   - sipping small amounts of water
   - drinking carbohydrate/electrolyte-containing drinks
   - sucking on Popsicles made from juices
   - sucking on ice chips
   - sipping through a straw

Question 26

Effects of alcohol

Answer 26

1. The most widely used and abused drug
2. May be used medicinally or consumed as a beverage
3. Depressing effect on nervous system and dulling of the senses
4. Adverse effects:
   - impaired judgment
   - decreased sense of responsibility
   - decreased coordination
   - constricted visual field
   - diminished memory
   - reduction in reasoning
   - lower attention span
   - increased frequency of errors
5. Intoxication:
   - determined by the amount of alcohol in bloodstream
   - measures as a % by weight in blood
   - depends on amount of alcohol consumed, rate of consumption, how long you have been drinking, and food in stomach

Question 27

Depressants

Answer 27

1. Drugs which reduce the bodies functions
   - lower blood pressure
   - reduced mental processing
   - slow motor and reaction responses
2. Examples:
   - tranquilizers
   - motion sickness meds
   - stomach meds
   - decongestants
   - antihistamines
   - alcohol

Question 28

Stimulants

Answer 28

1. Drugs which excite the nervous system and produce an increase in alertness and activity
   - amphetamines
   - caffeine nicotine
2. Stimulants can produce anxiety and drastic mood swings which are dangerous in flight

Question 29

Pain killers

Answer 29

1. Analgesics:
   - over the counter
   - have few side effects when used properly, and usually do not restrict flying
   - aspirin
   - Tylenol
   - Advil
2. Prescription:
   - may include side effects such as mental confusion, dizziness, headaches, nausea, and vision problems, may restrict flying
   - darvon
   - percodan
   - Demerol
   - codeine
3. Anesthetics:
   - drugs which deaden pain or cause loss of consciousness
   - commonly used in dental or surgical procedures
   - usually does not restrict flying as much as the mental procedure and subsequent pain does

Question 30

Nitrogen excess

Answer 30

1. Decompression sickness “the bends”
2. Usually caused by scuba diving
   - the reduction of the atmospheric pressure can cause physical problems
   - it occurs when nitrogen absorbed during a dive forms bubbles in the body tissue and the bloodstream as pressure decreases
   - can cause pain, paralysis, or death
3. Recommended wait time:
   up to 8000’ MSL
   - dive did not require a controlled ascent- 12hrs
   - dive did require a controlled ascent - 24hrs
   Above 8000’ MSL
   - any dive 24 hours