AP103 Altitude Threats Flashcards
During ascent (as ambient pressure decreases), gases trapped within the body cavities will _____
Expand
What are the four areas of the body influenced by the mechanical effects of trapped gases
Ears, Sinuses, G.I. tract, Teeth
What is the best method of preventing problems with the ears and sinuses in-flight?
Do not fly with a cold
What are the four DCS types?
Bends, Chokes, Skin manifestations, and CNS (neurological manifestations
Symptoms of the Bends
-Deep, dull boring pain in a joint
-Pain may involve the muscles
-Usually occurs in shoulders, knees, elbows, and ankles
Symptoms of the Chokes
-Deep, sharp pain centrally located under the sternum
-Difficulty with inspiration
Symptoms of Skin Manifestations
-Mottles and diffuse rash
-Itching sensation
Symptoms of CNS
-Visual disturbance
-Partial paralysis, loss of speech or hearing
-Severe, persistent headache
-Vertigo, loss of orientation
-Tingling of one arm, leg, or side of the body
DCS is caused by ____ coming out of solution in the tissues and blood
Nitrogen
List, in order, the corrective actions for any suspected/observed DCS
- 100% or maximum oxygen
- Immobilize the affected area
- Land as soon as practical
- Obtain medical assistance (flight surgeon)
- Hyperbaric therapy
What is considered adequate protection against DCS
Cabin pressure and denitrogenation
The USAF forbids flight within ______ hours of compressed air exposure for all normal flying operations
24
What is hypoxia?
A state of oxygen deficiency in the blood, cells, or tissues sufficient to cause impairment of function
What kind of hypoxia is usually caused by exposure to low barometric pressure?
Hypoxic hypoxia
What are the four types of hypoxia?
Hypoxic hypoxia, Stagnant hypoxia, Hypemic hypoxia, Histotoxic hypoxia
Causes of Hypoxic hypoxia
-Loss of cabin pressurization
-Improper use of oxygen equipment
-Oxygen equipment malfunctions
Causes of Stagnant hypoxia
-Cold temperatures
-Shock
-Hyperventilation
-G Forces
Causes of Hypemic hypoxia
-Drugs
-Carbon monoxide
-Blood donation
Causes of Histotoxic hypoxia
-Alcohol
-Cyanide
What is the most dangerous characteristic of hypoxia?
Insidious onset
What are signs/symptoms are normal associated with hypoxia?
-Bluing (cyanosis)
-Impaired Vision
-Hot or cold flashes
-Dizziness
-Lightheadedness
-Loss of muscle coordination
-Apprehension
-Feeling of well being
-Tingling
-Impaired judgement/confusion
True or False: The time of onset of hypoxia and the severity of symptoms are identical with all crewmembers from one day to the next
False
What is the term for the period of time from the interruption of the oxygen supply or exposure to on oxygen poor environment, to the time when useful function is lost?
Time of useful consciousness (TUC)
What factors decrease TUC?
-Increased physical activity
-Stress
-Hypoxia (histotoxic, hypemic, stagnant)
-Rapid decompression
-Anxiety
-Increased altitude
