Flight Physiology Flashcards
Boyle’s Law
“Boyle’s Balloon” P1 x V1 = P2 x V2
Increased altitude = increased volume due to decreased pressure.
Dalton’s Law
“Dalton’s Gang” - PT = P1 + P2 + P3…
Increased altitude = Decreased gas pressure without lowering percentage of gas. Causes hypoxia at altitude.
Normal Torr at sea level
760
Atmosphere gas composition
21% Oxygen
78% Nitrogen
1% Other
Henry’s Law
“Henry’s Heineken” P=KHC
Gas in a solution varies directly with the partial pressure of that same gas over the solution. Causes VQ mismatch due to pressure difference.
Charles Law
“Charging Charles” V1/V2 = T1/T2
Gas volume expands when heated and contracts when cooled. Pressure is constant!
Each 100m in elevation causes a temperature drop of?
1*C
Gay-Lussac’s Law
“Charles gay brother” P1/T2 = P2/T2
As temperature changes, pressure changes. Volume stays the same! Oxygen bottle in the sun.
Graham’s Law
“Graham’s grape jelly”
Gases with smaller mass diffuse faster than larger mass gasses.
Barotitis Media
Descent problem.
Air trapped in middle ear
Barodontalgia
Ascent problem.
Air trapped under recent dental work.
Treatment of Barodontalgia
Slower ascent, consider analgesics
Barosinusitis
Ascent problem.
Descend, slower climb, neosynephrine, analgesics
Barobariatrauma
Nitrogen from fatty tissue is released into plasma causing nitrogen narcosis.
Treatment of Barobariatrauma
Pre-oxygenate obese patient’s with 100% oxygen causing nitrogen washout.
Stressors of flight (8)
Decreased partial pressure of oxygen Barometric pressure changes Thermal changes Decreased humidity Noise Vibration Fatigue G-forces
Factors effecting stressors of flight
D- Drugs E- Exhaustion A- Alcohol T- Tobacco H- Hypoglycemia
MSL
Mean sea level
AGL
Above ground level
ATM
Atmosphere
Torr
Measurement of pressure in mmHg
PSI
Measurement of pressure in pounds
At sea level, 1 ATM weights?
14.7 lbs or 760 torr
0.5 ATM or 380 torr is at what altitude?
18,000
1 ATM every ___ while diving.
33 feet
Calculate partial pressure of oxygen on a normal day at sea level.
.21% x 760 torr = 159.6 torr
Physiologic zone
Sea level to 10,000
Physiological zone
10,000 to 50,000
Space-Equivalent zone
50,000 to 200,000
Hypoxic Hypoxia
Deficiency in alveolar O2 exchange. (Altitude hypoxia)
Stagnant Hypoxia
Reduced cardiac output or pooling of blood (Heart failure, shock)
Histotoxic Hypoxia
Inability to use present O2 in tissues due to poisioning. (Cyanide)
Hypemic Hypoxia
Reduction in O2 carrying capacity of blood. (Trauma with hemorrhage, Anemia, CO)
Indifferent stage of hypoxia
Increased HR and RR. Decreased night vision.
Night vision decreases at what altitude?
5000
Compensatory stage of hypoxia
Increased BP, impairment of task performance
Disturbance stage of hypoxia
Dizzy, sleepy, tunnel vision, cyanosis
Critical stage of hypoxia
Marked confusion and incapacitation
Pa02 decreased by ___ for every ___ increase in altitude
5 mmHg
1000 FT
Oxygen adjustment calculator
(Fio2 x P1) / P2 = Fio2 at altitude
Effective performance time
Amount of time a crew member is able to perform useful flying duties in an inadequately oxygenated environment
Time of useful consciousness
Elapsed time from exposure to oxygen deprived environment to the point when function is lost
Explosive decompression
1/2 of TUC compared to controlled decompression
S/S of Type I Decompression Sickness
Painful joints
Mottled skin
Itching
S/S of Type II Decompression Sickness
Neurological S/S
Hypovolemic shock
Signs of compression loss at altitude
Cooler cabin temperatures
Windows fogging
TUC at 30,000 ft MSL
90 seconds
45 seconds with rapid decompression
Every ___ increase in elevation causes temperatures to drop ___.
1000 ft
2*C
