What is Hypoxia?
A lack of sufficient oxygen to meet the needs of the body tissues, enough to cause impairment of function.
Name types of Hypoxia.
- -Hypemic Hypoxia
Name stages of Hypoxia, their altitudes, and symptoms.
- -Indifferent (zone of adaptability), 0-10,000ft, no real impairment
- -Compensatory, 10,000-15,000ft, impairment after some time: short term memory lapses, judgement lapses
- -Disturbance, 15,000-20,000ft, body has no protection against hypoxia, normal symptoms begin
- -Critical, 20,000ft-up, rapid decrease in capabilites
Name signs & symptoms of Hypoxia.
- External Sym: reasoning difficulties, headache, poor motor coordination, cyanosis, increased perspiration, increases rate & depth of respiration
- Internal Sym: vision impairment, euphoria, hot-cold flashes
- Every person has their own symptoms.
Cause & treatment of Hypoxic Hypoxia.
- Caused by lack of partial pressure of O2, in order to transfer to the tissues; considered a disruption of the O2 alveolar exchange. (altitude, vacuums, etc.)
- Treatment- reduce altitude, supplemental oxygen
Cause & treatment of Hypemic Hypoxia.
- Oxygen deficiency due to the reduction of the oxygen caring capcity of blood; common causes are carbon monoxide (binds with Iron in hemoglobin 255 times stronger than O2).
- Treatment- remove contamination & exposure to O2
Cause & treatment of Stagnant Hypoxia.
Blood pools and/or is unable to move. Body parts falling sleep, G-lock, and heart failure.
Cause & treatment of Histotoxic Hypoxia.
Tissues are unable to use O2 (alcohol, cyanide).
2 ways O2 systems are stored.
- High pressure bottles marked green (1800 to 2200psi) or low pressure (400-450psi).
List types of O2 systems & usable altitudes.
- Continuous Flow- below 18,000 up to 28,000ft.
- Dilutor Demand- up to 40,000ft.
- Pressure Demand- 40,000- 50,000ft.
Describe Continuous Flow O2 system.
- Most basic, uses ambient air pressure & increases the percent of O2 person receives.
- Types: nasal cannula, basic masks, airline "pig snouts"
Describe Dilutor Demand O2 system.
Sealed mask that increases amount of O2 mixed with cabin air until its giving 100% O2. Will only provide air when wearer inhales, flow stops when exhaling.
Describe Pressure Demand O2 system.
Simialr to diluter demand, this system increases the pressure of the air given as it climbs as well as the oxygen.
Altitude at which full protection from hypoxia at 100% O2.
Altitude at which 100% O2 will be at partial pressure of 10,000ft.
Maximum safe amount of pressure you can add to O2.
40mm, above this alveoli in lungs may pop. 60mm can be deadly.
What is hyperventilation?
- Breathing at a rate that is greater than required for current activity level. Normal trigger for inspiration if CO2 level.
- Sym: lightheadedness, nausea, coolness, muscle spasms
- Treatments: consciously control breathing, talk loudly, re-breathing
At night, what is affected and O2 should be used at what altitude?
What is Boyles Law?
If you keep temperature constant, volume will be inversely proportional to pressure: p1/p2 = v2/v1
What is Dalton's Law?
The total pressure of a mixture of gases is the sum of all of the partial pressures of gases.... Pt= Po2+ Pn2 + Pco2+ .... (this is how hypoxic hypoxia occurs, there isn't enough pressure).