Module 10 - Flight Physiology, Safety, Survival, CAMTS Flashcards
1
Q
- Initial intervention for managing a patient presenting with bariobariatrauma is?
A. Administer high flow oxygen
B. Decrease oxygen to 4 L/minute by NC
C. Administer high flow oxygen by NRM 15 minutes prior to lift off
D. Maintain cabin pressure at 2,500 feet
A
- C: Nitrogen, always present in body fluids, comes out of solution and forms bubbles if the pressure on the body drops sufficiently as it does during ascent into the higher altitudes. Overweight persons (bariobariatrauma) are more susceptible to evolved gas decompression sickness (DCS) as fatty tissue contains more nitrogen. Henry’s and Dalton’s laws predict that, as the diver descends, excess nitrogen will enter the blood and all body tissues. These laws also predict that, on ascent (as ambient pressure decreases) the extra nitrogen that accumulated will diffuse out of the tissues and into the circulation. DCS arises when excess nitrogen leaving tissue forms bubbles large enough to cause symptoms. Size of bubbles is important, since small bubbles can often be found in divers with no symptoms. DCS arises when the pressure gradient for nitrogen leaving the tissues is so great that large bubbles form, probably by coalescence of many smaller bubbles. Large bubbles within tissues and the circulation cause the symptoms and signs of DCS. Diving DCS: A diver ascends from a dive. Altitude DCS: An aircraft flies upward (ascent).
2
Q
- An expanding ETT cuff in flight is an indication of what gas law?
A. Henry’s law
B. Dalton’s law
C. Boyle’s law
D. Charles’ law
A
- C: Boyle’s law (expansion or contraction of a gas) describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system. The air in the ETT cuff, for example, expands with altitude (ascent) and contracts during descent. Boyle’s law is one of three gas laws that thoroughly describe the behavior of gases under varying temperatures, pressures, and volumes. The other two laws are Gay-Lussac’s law and Graham’s law. Graham’s law of effusion and diffusion states that the rates of movement of gases at the same temperature and pressure are inversely proportional to the square root of its molecular mass. Dalton’s law of partial pressures states that the total pressure of a gas mixture is the sum of the individual or partial pressures of all the gases in the mixture. Charles’s law, or the law of volumes, states that for an ideal gas at constant pressure, the volume is proportional to the absolute temperature, which describes how gases tend to expand when heated.
3
Q
- Your oxygen tank pressure reading at 1,200 hours was 1,800 psi. The pilot rechecked the unused oxygen tank in the evening and reported that the gauge reading was 1,500 psi. Which gas law best describes the decrease in pressure?
A. Gay-Lussac’s law
B. Dalton’s law
C. Boyle’s law
D. Henry’s law
A
- A: Gay-Lussac’s law states that the pressure of a sample of gas at constant volume is directly proportional to its temperature. Simply, if a gas temperature decreases, then so does its pressure, if the mass and volume of the gas are held constant. The oxygen tank pressure (psi) changes are directly proportional to temperature is an example of this law.
4
Q
- How should your flight suit fit to provide space of insulation per CAMTS recommendations?
A. ½ in.
B. 1 in.
C. Skin tight so I look really hot for the firefighters on scene
D. ¼ in.
A
- D: The uniform should fit to allow 0.25 in. (1/4 in.) of air space between the suit and undergarments.
5
Q
- You are beginning to prepare for landing and you have news reporter riding along for the day. You see a high-rise tower at 1,100 high. Sterile cockpit applies how?
A. The news reporter can speak anytime during the flight
B. Flight crew members are the only one allowed to speak
C. Say nothing about the high-rise tower
D. Pilot is the only crew member to speak during all phases of flight
A
- B: Observance of a sterile cockpit is a regulation of the Federal Aviation Administration (FAA) (FAR 135.100) that prohibits nonessential communications between the medical crew and pilot during critical phases of flight. The critical phases of flight include all ground operations that involve taxi, takeoff, and landing and all other flight operations except cruise flight. The medical crew should be aware that there are certain times when they should refrain from speaking to the pilot unless absolutely imperative. These times include the following: during takeoff, during landing, during instrument approaches, and in dense air traffic areas.
6
Q
- You have just crash landed your aircraft and your pilot has asked you to exit the aircraft. What should you take with you?
A. Helmet
B. Bags of normal saline
C. Survival kit
D. Seat cushion
A
- C: Survival equipment (kit or bag) should be standard on every air medical aircraft. Specific service area, climate, type of aircraft, and time of year are considerations when survival gear is assembled. The survival gear should be assembled and stored in a manner that affords easy access.
7
Q
- You are transporting a non-intubated seventy-year-old man with a history of bilateral pneumonia on 2 L of oxygen by nasal cannula. You are at 10,000 feet and the patient’s vital signs are BP 190/100, HR 102, RR 24, and SaO2 86%. What is the immediate intervention for this patient?
A. Decrease cabin pressure
B. Increase oxygen delivery to the patient
C. Administer fluid bolus to increase perfusion to heart
D. RSI and intubate the patient
A
- B: Hypoxic hypoxia is also referred to as altitude hypoxia because its primary cause is exposure to low barometric pressure. It is a deficiency in alveolar oxygen exchange, which interferes with gas exchange in two phases of respiration: ventilation and diffusion. A reduction in PO2 in inspired air or the effective gas exchange area of the lung may cause oxygen deficiency. The result is an inadequate oxygen supply to the arterial blood, which in turn decreases the amount of oxygen available to the tissues. Decreased barometric pressure at high altitudes causes a reduction in the alveolar partial pressure of oxygen (PaO2). The blood oxygen saturation, which is 98% at sea level, is reduced to 87% at 10,000 feet and 60% at 22,000 feet. The most effective way to prevent physiologic problems is to provide an aircraft pressurization system so that occupants of the aircraft are never exposed to pressure outside the physiologic zone. In those cases in which ascent above the physiologic zone is required, protective oxygen equipment must be provided. Treatment of hypoxia is administration of 100% oxygen.
8
Q
- You are transporting a thirty-year-old man who was involved in a motor vehicle crash. He has a closed femur fracture with a history of alcohol consumption of unknown amount. On the basis of the physiologic effects elicited on the body, which type of hypoxia problems may occur in flight?
A. Histotoxic and hypemic
B. Hypoxic and stagnant
C. Stagnant and hypemic
D. Hypoxic and hypemic
A
- A: Histotoxic hypoxia is the inability of cells to take up or utilize oxygen from the bloodstream, despite physiologically normal delivery of oxygen to such cells and tissues. Histotoxic hypoxia results from tissue poisoning, such as that caused by alcohol, narcotics, cyanide (which acts by inhibiting cytochrome oxidase), and certain other poisons like hydrogen sulfide (byproduct of sewage and used in leather tanning). Hypemic hypoxia is where arterial oxygen pressure is normal, but total oxygen content of the blood is reduced, as from various types of anemia or from a loss of blood. Stagnant hypoxia occurs when conditions exist (cerebral ischemia, ischemic heart disease, intrauterine hypoxia) that result in reduced cardiac output, pooling of the blood within certain regions of the body, a decreased blood flow to the tissues, or restriction of blood.
9
Q
- Which one of the following has been determined to be an unreliable sign of hypoxia?
A. Cyanosis
B. Hypertension
C. Tachycardia
D. Tachypnea
A
- A: Cyanosis has been determined to be an unreliable sign of hypoxia because the oxygen saturation must be below 75% in patients with normal hemoglobin before it is detectable. Hypotension and cyanosis are late signs of hypoxia. Providing adequate supplemental oxygen is the prime consideration in the treatment of hypoxia.
10
Q
- An increase in altitude produces?
A. High humidity and high temperature
B. Low humidity and low temperature
C. High humidity and low temperature
D. Low humidity and high temperature
A
- B: Humidity is the concentration of water vapor in the air; as air cools, it loses its ability to hold moisture because temperature is inversely proportional to altitude; an increase in altitude produces a decrease in temperature and, therefore, a decrease in the amount of humidity. Increase in altitude = low temperature and low humidity.
11
Q
- After a forced aircraft landing, the pilot is incapacitated; your main priority is to?
A. Assume crash position
B. Turn off oxygen
C. Turn off throttle, fuel, and then battery
D. Turn on the emergency locator transmitter (ELT)
A
- C: After a forced aircraft landing, the main danger is fire. If the pilot has become incapacitated, the throttle, fuel switch and master battery in sequence, should be turned off. The position of these switches varies with the aircraft, and the flight team must be familiar with the procedure for their specific aircraft.
12
Q
- Your immediate concerns of survival after an aircraft accident include all of the following, except?
A. Obtain water and go for help
B. Building a fire
C. Making appropriate fire signals
D. Creating or seeking shelter
A
- A: Knowledge of the rule of threes when priorities are set will greatly increase the chances of survival in the outdoors. This rule states that the average person can survive three minutes without oxygen, three hours without shelter in extreme conditions, three days without water, and three weeks without food. Medical concerns and safety are important in accident, but once these are addressed, the rule of threes should guide priorities. With this rule in mind, the flight team’s immediate concerns after an accident should be creating or seeking shelter, building a fire, and making appropriate fire signals.
13
Q
- No pilot may takeoff or land an aircraft under visual flight rules (VFR) when the reported ceiling or visibility is less than which of the following for local day weather minimums?
A. 1,000 feet and 1 mile
B. 500 feet and 1 mile
C. 500 feet and 2 miles
D. 800 feet and 1 mile
A
- B: One of CAMTS’s standards is a recommendation for weather minimums. It seems that weather, particularly fog, which can impair pilot visualization, continues to be a cause of helicopter crashes. Flight programs need to establish weather minimums based on the terrain in which they operate and then adhere to them. The definition of weather minimums is the lowest (worst) visibility conditions under which an aircraft may legally be flown under (VFR). When visibility is less than specified minimums, an aircraft must fly under IFR or not at all. VFR “response” weather minimums must meet or exceed as outlined in FAA-A021.
14
Q
- The emergency transmit frequency is?
A. 121.5
B. 155.5
C. 120.5
D. 105.5
A
- A: Airband frequencies of 121.5 MHz and 243.0 MHz are internationally designated distress signal channels.
15
Q
- Average time of useful consciousness (TUC) for a non-pressurized aircraft at 45,000 feet is?
A. 90 seconds
B. 3-5 minutes
C. 30-60 seconds
D. 15 seconds or less
A
- D: TUC refers to the elapsed time from the point of exposure to an oxygen-deficient environment to the point at which deliberate function is lost. Rapid decompression, which occurs when a quick loss of cabin pressure occurs in a pressurized aircraft at high altitudes, dramatically reduces the time of useful consciousness. On decompression at altitudes above 33,000 feet, an immediate reversal of oxygen flow in the alveoli takes place, caused by higher PO2 within the pulmonary capillaries that depletes the blood’s oxygen reserve. The causes of hypoxia include high altitude, hypoventilation, and pathologic condition of the lung.
16
Q
- You are asked to respond to a local scene call with night vision goggles (NVG) capability involving an MVA with multiple injured patients at 2,300. You have been having bad weather off and on. The pilot-in-command (PIC) advises you that weather minimums are currently at 800 and 1. What will you do?
A. Continue and fly to the scene
B. Attempt to fly to the scene and see if you can get there
C. Abort the flight due to weather
D. Say nothing because the PIC is responsible for deciding wheather or not you continue with the mission
A
- C: Each program must have a policy that allows any crew member to refuse or abort a flight if they feel uncomfortable. The flight is aborted because the weather minimum of 800 foot ceiling and 1 mile visibility is less than the specified minimums recommended for local-night with the use of NVG of a 800 foot ceiling and 3 mile of visibility.
17
Q
- The percentage of oxygen at 25,000 MSL is
A. 4%
B. 21%
C. 18%
D. 7%
A
- B: Oxygen concentration remains at 21% regardless of altitude. However, oxygen availability decreases with altitude because the oxygen molecules are farther apart, potentially resulting in hypoxia.
18
Q
- The altitude at which one begins to lose their night vision is
A. 500 feet
B. 1,000 feet
C. 3,000 feet
D. 5,000 feet
A
- D: Night vision loss occurs at 5,000 feet, which is part of the first stage of hypoxia which is called the indifferent stage. Four stages of hypoxia need to be considered when examining its effect on human pathophysiology. The four stages are divided by altitude.
19
Q
- The pilot made contact upon the aircraft lifting at 1455. The second contact was at 1510 after landing. The communication center has not heard from the transport team since the last flight following transmission. The postaccident incident plan (PAIP) should be initiated at what time?
A. 1525
B. 1540
C. 1555
D. 1610
A
- C: The PAIP becomes the road map for the communication center staff to initiate the necessary critical steps that enhance crew survival and limit the program’s liability. Priorities include verifying facts (crash location, etc.); dispatching rescue crews (civil air patrol, air medical, or ambulance response to the crash site); activating notification list according to the PAIP; and notifying security for crowd control at base of operations and/or hospitals. CAMTS recommends the following for time between each communication during flight and ground operations.
20
Q
- Gas that diffuses from an area of higher concentration to an area of lower concentration, best describes which gas law?
A. Graham’s law
B. Charles’ law
C. Gay-Lussac’s law
D. Henry’s law
A
- A: Graham’s law, also known as Graham’s law of effusion states that the rate at which gas molecules diffuse is inversely proportional to the square root of its density (same as the square root of its molecular weight). This means that gases will flow from a higher pressure or concentration to an area of lower pressure or concentration. Simple diffusion and gas exchange at the cellular level are examples of this gas law.
