Human Factors Flashcards
Define hypoxia
Hypoxia is a state of oxygen deficiency in the body that can impair the brain.
Hypoxia is the inability of the heart to deliver oxygen to the major organs. The two organs that need oxygen the most are the brain and the eyes.
List the 4 types of hypoxia
Hypoxic - Also referred to as altitude hypoxia. The percentage of oxygen is the same but the molecules are less concentrated.
Histotoxic - The inability of the body to use the oxygen. Toxic substances get into the blood and prevent oxygen from getting to the organs.
Hypemic - Caused by anemia, a disease, blood loss, deformed blood cells, or carbon monoxide poisoning.
Stagnant - Oxygen deficiency in the blood due to poor circulation. If a pilot has a weak heart or heart failure.
Define hypoxic hypoxia
Also referred to as altitude hypoxia. The percentage of oxygen is the same but the molecules are less concentrated.
Define hypemic hypoxia
Caused by anemia, a disease, blood loss, deformed blood cells, or carbon monoxide poisoning.
Define stagnant hypoxia
Oxygen deficiency in the blood due to poor circulation. If a pilot has a weak heart or heart failure.
Define histotoxic hypoxia
The inability of the body to use the oxygen. Toxic substances get into the blood and prevent oxygen from getting to the organs.
Hypoxia symptoms can occur as low as
5000 ft
What impairments does hypoxia start to cause around 12,000 - 15,000 feet?
List some physical and emotional symptoms.
Judgment, alertness, memory loss, coordination, ability to make calculations.
Headache, drowsiness, euphoria, belligerence.
List some factors that increase the risk of hypoxia
- CO from smoking or the planes exhaust
- Anemia
- Medicines
- Alcohol
The body needs more oxygen if extremely hot, cold, has a fever, or is anxious.
List 3 ways to avoid hypoxia
- Enrich the air with oxygen from an appropriate oxygen system
- Maintain a safe cabin pressure altitude
- Use a pulse oximeter
Define hyperventilation.
Why is CO2 needed?
Hyperventilation is an increase in breathing resulting in a significant decrease in carbon dioxide in blood.
CO2 is needed to regulate breathing.
What are some hyperventilation symptoms?
- lightheadedness
- suffocation
- drowsiness
- tingling
- coolness
- incapacitation
- disorientation
- muscle spasms
How do you reverse hyperventilation?
Through normal / slowed breathing
Breathe in / out of a paper bag
What is an “ear block”?
What does it cause?
Air in middle ear pushes open the Eustachian tube to nasal passages during climb, but doesn’t do that during descent.
Severe pain and loss of hearing for hours to days.
“Ear block” is prevented by
- Swallowing
- Yawning
- Tensing throat
- Valsalva maneuver - close mouth, pinch nose, blow through nostril
Avoid flying with upper respiratory infection or nasal allergies.
What is spatial disorientation?
The body’s inability to know where it is while in motion. The eyes see one thing, and the brain senses something different.
Awareness of orientation of aircraft and oneself in relation to known reference point.
Spatial disorientation is caused by 3 main sensory areas:
Visual
Vestibular - sensing system of inner ear
Postural - nerves in skin, joints, muscles of body
What causes motion sickness?
Continuous stimulation of the inner ear, which controls balance.
What are symptoms of spatial disorientation?
- desire for food is lost
- saliva collects in mouth
- perspiration
- nauseous
- vomitting
- incapacitation
What actions can be taken if a pilot or passenger has motion sicknesss?
- open up air vents
- use supplemental oxygen
- loosen clothing
- keep eyes on one point outside of the aircraft
- avoid moving head
- cancel flight and land
What is carbon monoxide poisoning?
Carbon monoxide is breathed in, and it reduces the ability of blood to carry oxygen.
CO causes hypoxia (hypemic).
What is CO?
A colorless, odorless, tasteless gas contained in exhaust fumes.
What are the symptoms of CO poisoning?
- headache
- drowsiness
- dizziness
How is CO poisoning caused?
Heaters used with exhaust gas fumes escaping through manifold cracks.
What steps do you take if CO poisoning is suspected?
Turn off the heater
Open vents
Land
What are the effects from scuba diving?
The body needs time to rid itself of excess nitrogen.
Decompression sickness can occur even if low altitude is encountered.
Below and up to 8,000 feet (actual not cabin as decompression is a risk):
- Wait 12 hours if no controlled ascent required
- Wait 24 hours if controlled ascent was required
Above 8,000 feet
-Wait 24 hours for any dive
OTC cold medicine is to be avoided because…
…changes in atmospheric pressure can cause impaired judgment and performance.
