FP-C - Flight Paramedic-Certification Flight and Transport Physiology Questions and Answers — Questions and Answers
Question 1: A patient with a pneumothorax is being transported by helicopter. As the aircraft ascends, the flight paramedic should be most concerned about which of the following gas laws causing a potential life-threatening emergency?
- Dalton's Law
- Henry's Law
- Boyle's Law (Correct answer)
- Charles's Law
Correct answer: Boyle's Law
Boyle's Law states that the volume of a gas is inversely proportional to the pressure. As the helicopter ascends, the atmospheric pressure decreases, causing the trapped air in the patient's pleural space to expand. This expansion can convert a simple pneumothorax into a tension pneumothorax, which is a life-threatening emergency.
Question 2: You are transporting a patient with COPD from a rural facility at sea level to a tertiary care center located at a higher elevation. According to Dalton's Law, what physiological challenge should you anticipate?
- Increased FiO2 requirement due to lower partial pressure of oxygen. (Correct answer)
- Expansion of gases in the bullae, causing a pneumothorax.
- Decreased oxygen cylinder duration due to temperature changes.
- Increased risk of decompression sickness.
Correct answer: Increased FiO2 requirement due to lower partial pressure of oxygen.
Dalton's Law states that the total pressure of a gas mixture is the sum of the partial pressures of each gas. While the percentage of oxygen in the atmosphere remains 21% at altitude, the total atmospheric pressure is lower. This results in a decreased partial pressure of inspired oxygen (PiO2), leading to hypoxic hypoxia. Patients with pre-existing respiratory conditions like COPD will likely require an increased FiO2 to maintain adequate oxygen saturation.
Question 3: A flight paramedic is preparing to transport a patient with an endotracheal tube in a fixed-wing aircraft for a long-distance flight. To mitigate the effects of Boyle's Law on the ET tube cuff, the most appropriate action is to:
- Inflate the cuff with the maximum recommended volume of air before takeoff.
- Deflate the cuff completely during ascent and reinflate it at cruising altitude.
- Inflate the cuff with sterile saline instead of air.
- Continuously monitor the cuff pressure with a manometer and adjust as needed. (Correct answer)
Correct answer: Continuously monitor the cuff pressure with a manometer and adjust as needed.
While inflating the cuff with saline is a technique used, the most universally correct and safest answer is to continuously monitor the cuff pressure with a manometer. As the aircraft ascends, the air in the cuff will expand due to Boyle's law, potentially causing excessive pressure on the tracheal wall and leading to tissue necrosis. Conversely, during descent, the cuff volume will decrease, which could lead to an air leak and inadequate ventilation. Continuous monitoring and adjustment ensure the cuff pressure remains within the safe and effective range (typically 20-30 cm H2O).
Question 4: Which of the following physiological stressors of flight is responsible for causing dehydration, drying of mucous membranes, and potentially thickening respiratory secretions?
- Vibration
- Decreased Humidity (Correct answer)
- Noise
- Gravitational Forces
Correct answer: Decreased Humidity
The air at higher altitudes is significantly less humid. Aircraft cabin air is often very dry, which increases the rate of evaporation from a patient's skin and respiratory tract. This leads to dehydration, drying of mucous membranes, and can cause respiratory secretions to become thicker and more difficult to clear, posing a risk for patients with respiratory conditions.
Question 5: A diver who ascended too rapidly is being transported for suspected decompression sickness. The formation of nitrogen bubbles in the blood and tissues is primarily explained by which gas law?
- Gay-Lussac's Law
- Boyle's Law
- Dalton's Law
- Henry's Law (Correct answer)
Correct answer: Henry's Law
Henry's Law states that the amount of gas dissolved in a liquid is directly proportional to the partial pressure of that gas above the liquid. During a dive, increased ambient pressure causes more nitrogen to dissolve in the diver's blood and tissues. If the diver ascends too quickly, the ambient pressure drops rapidly, and the dissolved nitrogen comes out of solution to form bubbles, leading to decompression sickness.
Question 6: During a winter flight in a rotor-wing aircraft, the flight crew notes that the pressure gauge on their main oxygen cylinder reads lower than it did during their pre-flight check in the heated hangar. This phenomenon is best explained by:
- Charles's Law
- Dalton's Law
- Gay-Lussac's Law (Correct answer)
- Boyle's Law
Correct answer: Gay-Lussac's Law
Gay-Lussac's Law states that for a fixed volume of gas, the pressure is directly proportional to its absolute temperature. As the helicopter flies in the cold air, the temperature of the oxygen cylinder and the gas inside it decreases. This drop in temperature causes a corresponding decrease in the pressure of the gas within the cylinder.
FP-C - Flight Paramedic-Certification Flight and Transport Physiology Questions and Answers
A patient with a pneumothorax is being transported by helicopter.
As the aircraft ascends, the flight paramedic should be most concerned about which of the following gas laws causing a potential life-threatening emergency?