What are the four primary gases that make up the composition of the atmosphere?
- Nitrogen (78.03%)
- Oxygen (20.95%)
- Argon (0.93%)
- Carbon Dioxide (0.03%)
** trace gases account for 0.06% **
What are the four stages of hypoxia?
- Indifferent: 0 - 10k ft/asl; HR and RR slightly increase
- Compensatory: 10k - 15k ft/asl; Decreased alertness
- Disturbance: 15k - 20k ft/asl; Increased errors in judgement
- Critical: 20k - 23k; mental incapacitation and death
What is the maximum allowable slope for a helicopter LZ?
5º
The helicopter LZ can NOT have a slope that exceeds 5º.
In this atmospheric level, you would expect to see notable impairment due to hypoxia, resulting in noticeable deficits to those involved.
The Physiological Deficient Zone - 10,000 - 50,000 ft/ASL
What are the 8 primary stressors of flight?
- Hypoxia
- Barometric Pressure Changes
- Thermal Variations
- Decreased Humidity
- Fatigue
- Noise
- Vibration
- Gravitational Forces
_______ results in inadequate tissue oxygenation secondary to a metabolic disorder and/or poisoning of the cytochrome oxidase enzyme system resulting in cellular inability to utilize oxygen.
Histotoxic hypoxia -
- Cyanide poisoning
What is the ideal size for a helicopter landing zone?
100’ x 100’ is the ideal size for a helicopter landing zone.
What is the typical maximum distance utilized for rotor-wing air medical transport?
150 nautical miles is the typical maximum distance utilized for rotor-wing air medical transport.
- ** speed approximately 100 - 200 mph ***
- ** Altitude ≤ 10,000 ft/asl
______ law states that at a constant pressure, the volume of gas is directly proportional to its temperature.
Charles’ Law states that at a constant pressure, the volume of gas is directly proportional to its temperature.
V1 ÷ T1 = V2 ÷ T2
** for every 1ºC temperature decrease, gas volume will decrease 1/273; vise versa **
Your patient is becoming increasingly restless and agitated in flight. What should you consider first?
Hypoxia should be considered first.
What are the three layers of the atmosphere and their perspective altitude range?
- Physiological Zone: 0 - 10,000 ft/ASL
- Physiological Deficient Zone: 10,000 - 50,000 ft/ASL
- Space Equivalent Zone: 50,000 - 250,000 ft/ASL
What is the primary factor resulting is air medical transport helicopters?
Human error (77%) is the primary factor resulting is air medical transport helicopters.
Weather: 30%
Obstacle Strike: 20%
Mechanical: 17%
True or False:
If a sudden increase in altitude occurs, the effect of temperature will occur faster than a change of pressure on a contained gas.
False.
The contained gas will attempt to expand as temperature happens more slowly.
- ** Boyle’s Law vs. Charles’ Law ***
- ** it takes a LARGE amount of heat to effect a small amount of volume ***
The Federal Aviation Administration requires all Air Medical Transports to operate under and comply with which regulation:
Title 14 Part 135
** FAR 135 which governs all commuter, or on-demand commercial operations **
Can individual states impose regulations and/or restrictions on commercial air carriers?
No, the Airline Deregulation Act of 1978 prohibits states from imposing regulations and/or restrictions on commercial air carriers.
As a result of Boyle’s Law, which medical equipment might be adversely affected in aviation medicine?
(In no specific order)
- ETT cuff
- Balloon pumps
- Air splints
- IV drip sets
- NG/OG tubes
** as pressure decreases, the volume will increase **
For every 1,000 ft of altitude, the temperature will decrease by _______.
2ºC
For every 1,000 ft of altitude, the temperature will decrease by 2ºC.
______ results due to the decrease of partial pressure of oxygen (PaO2).
Hypoxia results due to the decrease of partial pressure of oxygen (PaO2).
Which gases are of the most concern to aviation medicine?
- Nitrogen (78%)
- Oxygen (21%)
- Carbon Dioxide (< 1%)
- Water (vapor)
What is the barometric pressure at sea level?
760 mmHg is the barometric pressure at sea level.
760 mmHg = 1 ATM (14.7 lbs at S/L)
** decreases with ascent; increases with decent **
______ results from inadequate oxygenation secondary to reduced partial pressures of oxygen in inspired air.
Hypoxic hypoxia -
** impaired gas exchange across alveolar-capillary membrane **
______ results from inadequate tissue oxygenation results due to the decrease of partial pressure of oxygen (PaO2). to reduced oxygen-carrying capacity.
Anemic (Hypemic) hypoxia -
There is adequate availability of oxygen molecules but an obstructive pathology prevents oxygen from diffusing across the alveolar membrane.
- CO poisoning
- Drugs
- Anemia
- Pulmonary Embolism
- COPD
- Pneumonia
______ law states that the total pressure of a gas mixture is the sum of the individual partial pressures of all the gases in the mixture.
Dalton’s Law states that the total pressure of a gas mixture is the sum of the individual partial pressures of all the gases in the mixture.
Pt = P1+P2+P3…
______ law states that when temperature remains constant, the volume of a gas is inversely proportional to its pressure.
Boyle’s Law states that when temperature remains constant, the volume of a gas is inversely proportional to its pressure.
P1 V1 = P2 V2
** inverse = opposite **
