Flight Physiology Flashcards
Barodentalgia Definition, Identification, and Treatment.
Excruciating pain caused by pressure increase in dental work or gum abscess. Identified as an ascent problem. Immediate abortion of flight.
Decrease in PaO2 per 1000 ft increase in altitude
5mmHg
Rapid decompression TOUC at 28,000 ft
2-3 minutes
Indifferent Stage of Hypoxia
Altitude 0-10,000ft SpO2 90-98% Decrease in night vision at 4,000 ft HR and RR increase Unaware of symptoms
Barobariatrauma Definition, Identification, and Treatment.
Nitrogen narcosis in morbidly obese patients. Identified as an ascent problem. High flow oxygen prior to departure.
Henry’s Law
The amount of gas dissolved in a solution is directly proportional to the pressure of the gas over the solution.
Rapid decompression TOUC at 35,000 ft
30-60 seconds
Altitude to temperature relationship
1000ft increase = 2 degrees celsius decrease
150m increase = 1 degree celsius decrease
Rapid decompression TOUC at 43,000ft and above
9-12 seconds
Boyle’s Law
As altitude increases the atmospheric pressure decreases and gas in an enclosed space will expand
P1V1=P2V2
Bedside PaO2 calculation
(P1 x FiO2) - 50
Increasing PEEP is an example of which law?
An example of Fick’s law
DEATH mnemonic
Drugs Exhaustion Alcohol Tobacco Hypoglycemia
Atmospheric Pressure at 18,000 ft (mmHg, torr, inHg, ATM)
380mmHg, 380 torr, 14.96 inHg, 0.5 ATM
Atmospheric Pressure at Sea Level (mmHg, torr, inHg, ATM)
760 mmHg, 760 torr, 29.92 inHg, 1 ATM
Critical Stage of Hypoxia
Altitude 20,000-25,000ft
SpO2 60-70%
Tremors, seizures, LOC, coma, death
Gay-Lussac’s law
For a given mass and constant volume of gas, the pressure exerted on the sides of it container is directly proportional to its absolute temperature.
Rapid decompression TOUC at 25,000 ft
3-5 minutes
Charles’ Law
The relationship between temperature and volume are proportional at a constant atmospheric pressure. As the temperature goes up, gas volume expands. As the temperature goes down, volume decreases.
Barotits Media Definition, Identification, and Treatment.
Inability to regulate temperature in inner ear due to eustachian tube blockage. Identified as a descent problem. Valsalva or chewing gum.
Dalton’s Law
The total pressure of gas mixture is the sum of the partial pressures of all gases. In addition, it describes how a pressure is exerted by a gas at various altitudes, and how that pressure affects the partial pressure of the said gas
PaO2
Partial pressure of oxygen in arterial blood
Smokers lose what percentage of their night vision at 5,000 ft ?
20%
Graham’s Law
The rate of the diffusion of a gas is inversely proportional to the square root of its molecular weight. This means that diffusion will happen at a faster rate if the gas is thinner and at a slower rate if the gas is heavier.
Disturbance Stage of Hypoxia
Altitude 15,000-20,000ft
SpO2 70-80%
Decrease in sense, CNS, and psychomotor
Signs: Hyperventilation and cyanosis
Increasing FiO2 is an example of which law?
An example of Dalton’s law
Compensatory Stage of Hypoxia
Altitude 10,000-15,000ft
SpO2 80-90%
Night vision < 50%
CNS symptoms: poor judgement, irritability, drowsiness
Rapid decompression TOUC at 18,000 ft
20-30 minutes
Providing PPV is an example of which law?
An example of Henry’s law
How long into gestation is surfactant typically produced?
37 weeks gestation
Calculation for desired FiO2 accounting for increase in elevation
(FiO2 x P1)/P2
Rapid decompression TOUC at 40,000 ft
15-20 seconds
Rapid decompression TOUC at 22,000 ft
5-10 minutes
Fick’s Law
The rate of diffusion of a gas across a permeable membrane is determined by the chemical nature of the membrane itself, the surface areas of the membrane, the partial pressure gradient of the gas across the membrane, and the thickness of the membrane.
Barosinusitis Definition, Identification, and Treatment.
Inability to regulate sinus pressure due to inflammation or blockage. Identified as an ascent problem. Valsalva or chewing gum.
PAO2
Partial pressure of oxygen in the alveoli
