Flight Medic Study Flashcards
Boyle’s Law
Boyle’s = Balloon = Barotrauma
The pressure of s gas is inversely proportional to the volume of a gas at a constant temperature.
(when a gas is pumped into an enclosed space, it will shrink to fit into that space, but the pressure that gas puts on the container will increase)
(Think Boyle’s Law if you see “pneumo”)
Boyle’s Law Effects?
ETT cuffs, MAST trousers, Air splints, IV drip rates (increases rate)
Pneumocephalus = intracranial pressure will increase
(Pneumothorax)
(IV drip rates - turn bag upside down and squeeze air out to releive pressure)
Dalton’s Law
“Dalton’s Gang” (additive gas law)
The total pressure of a gas mixture is the sum of the partial pressures of all the gases in the mixture (“dalton’s gang”)
Responsible for soft tissue swelling at altitude (uptake of inert gasses into tissue)
(All of the gases added together)
Charles’ Law
“Charging Charles”
At a constant pressure, the volume of gas is directly proportional to the absolute temperature of the gas.
Example of Charle’s Law
Charging an oxygen tank, the tank gets hot.
Gay-Lussac’s Law
Directly proportional relationship between temperature and pressure
(Pressure reading in the morning is due to temp drop)
Example of Gay-Lussac’s Law
Oxygen cylinder left outside overnight will have a lower pressure reading in the morning due to temperature drop.
This gas law also explains the reason you need to add air to your tires in the winter (colder temps lower pressure)
Graham’s Law
“Graham’s = Grey Matter”
Law of Gaseous Diffusion
Gas exchange at the cellular level
The rate of diffusion of a gas through a liquid medium is directly related to the solubility of the gas and inversely proportional to the square root of its density
Limits gas ability to move through liquid
Example of Graham’s Law
Example- gas bubbles coming out of exposed grey matter when at altitude
Henry’s Law
“Henry = Heineken”
Solubility of gas in liquid
The quanitity of gas dissoloved in 1cm of a liquid is proportional to the partial pressure of the gas contact with the liquid
Example of Henry’s law
Decompression Sickness / The Bends
Decompression Sickness “The Bends”
Related to Henry’s Law
There are 6 different types of DCS
Type I - Nitrogen related - painful joints, mottled skin, pruritic (itching)
May feel like ants are crawling on their skin
Cutis Marmorata - mottled skin, can often look like sunburn
Type II - Neurologic signs/symptoms, hypovolemic shock
Ground transport is preferred for ALL diving injuries/decompression sickness
Arterial Gas Embolism (AGE)
Related to Boyle’s Law
DEADILEST!!!
Caused by breath holding during ascent on a dive, air pushes through the alveoli and enters the skin in the neck/chest
Causes pneumothorax
May also have nose bleeds
AGE requires immediate hyperbaric treatment
Fly only in pressurized aircraft (fixed wing) or rotary wing <1000ft MSL (TAKE TRANSPORT ROUTE WITH LOWEST ALTITUDE)
Pulmonary Overpressurization
Related to Boyle’s Law
A syndrome that occurs when “breath holding” compressed air during ascent
The greatest pressure differences are just below the surface of the water (=4ft depth)
Atmosphere Calculations
Physiologic Zone
Sea Level - 10,000ft MSL
Night Vision is decreased begining at 5,000ft MSL
Physiologically Deficient Zone
10,000ft - 50,000ft MSL
Oxygen or pressurization required to survive at these altitutudes
Sign of compression loss = cooler temp in the cabin and windows fogging
Time of Useful Consciousness (TUC)
TUC normally 90 sec at 30,000ft
If rapid decompression occurs TUC in now 45 sec
(**always pick the lowest time**)
Oxygen Adjustment Calculation
(FiO2 x P1)/P2 = FiO2 required for ascent
FiO2 = fraction of inspired oxygen
P1 = the pressure you are at on the ground
P2 = the pressure you are flying to (cruising altitude)
Example: pt on NRB @0.5 FiO2 at sea level. You will be flying to altitude of 500, what will be the oxygen requirment at this pressure - 0.5 x 760 /500 = 0.76 FiO2.
Inherent Stressors of Flight
“Cold, High, Dry”
Self Imposed Stressors of Flight
Safety / CAMTS Critical Phases of Flight
Critical Phases of Flight
Only ESSENTIAL communication durig:
Takeoff, Landing (short final), Refueling, and Taxi (ground or air)
Does not apply for “straight/level (“cruising”) flight (less than 10k ft)
