BCEN CFRN® (Certified Flight Registered Nurse)
ACTUAL EXAM ALL QUESTIONS AND ANSWERS
ALREADY GRADED A+. 100% VERIFIED
SOLUTIONS | UPDATED PER LATEST
GUIDELINES | GRADED A+
GENERAL PRINCIPLES OF FLIGHT TRANSPORT NURSING PRACTICE
Transport Physiology, Gas Laws, and Altitude Physiology
Question 1
A flight nurse is transporting a patient with a known bowel obstruction at a cabin altitude of
8,000 feet. According to Boyle's Law, which physiological change is the greatest concern?
• A. Decreased oxygen saturation
• B. Expansion of trapped intestinal gas
• C. Increased risk of barotrauma to the lungs
• D. Decreased partial pressure of nitrogen
Answer: B. Expansion of trapped intestinal gas
Rationale: Boyle's Law states that the volume of a gas is inversely proportional to its pressure.
At altitude (decreased atmospheric pressure), trapped gas expands. In a patient with a bowel
obstruction, this can lead to abdominal distention, pain, vomiting, and potential perforation.
The flight nurse must anticipate this and consider nasogastric tube placement before or during
transport. While decreased oxygen saturation (Dalton's Law) is also a concern, the immediate
life-threatening risk from an obstructed bowel is gas expansion.
,Question 2
According to Dalton's Law, which gas is most affected by changes in altitude?
• A. Nitrogen
• B. Carbon dioxide
• C. Oxygen
• D. Carbon monoxide
Answer: C. Oxygen
Rationale: Dalton's Law states that the total pressure of a gas mixture is the sum of the partial
pressures of individual gases. As altitude increases, barometric pressure decreases, and the
partial pressure of oxygen (PaO₂) decreases proportionally. This is why patients may become
hypoxemic during air transport even if they were stable at sea level. While all gases are affected,
oxygen is the most clinically significant.
Question 3
A flight nurse is preparing to transport a patient at a cabin altitude of 10,000 feet. The patient
has a baseline PaO₂ of 70 mmHg on room air at sea level. What is the approximate PaO₂ at this
altitude?
• A. 60 mmHg
• B. 50 mmHg
• C. 40 mmHg
• D. 30 mmHg
Answer: B. 50 mmHg
Rationale: At 10,000 feet, the ambient PaO₂ is approximately 50 mmHg (down from ~100
mmHg at sea level). For a patient with a baseline PaO₂ of 70 mmHg on room air, oxygen
supplementation is almost certainly required during flight. The flight nurse must anticipate the
need for supplemental oxygen and have appropriate delivery devices available. The rule of
thumb is that for every 1,000 feet of altitude gain, oxygen requirements increase significantly.
Question 4
A patient is being transported in a fixed-wing aircraft at 35,000 feet with a cabin altitude of
,8,000 feet. The flight nurse notes the patient's oxygen saturation dropping despite being on a
non-rebreather mask at 15 L/min. Which intervention is most appropriate?
• A. Increase the oxygen flow rate to 20 L/min
• B. Switch to a bag-valve-mask ventilation
• C. Administer positive end-expiratory pressure (PEEP)
• D. Consider intubation and mechanical ventilation
Answer: D. Consider intubation and mechanical ventilation
Rationale: When a patient is hypoxemic despite high-flow oxygen via non-rebreather mask, the
next step is to consider intubation and mechanical ventilation. At altitude, the reduced
barometric pressure makes oxygenation more challenging. Mechanical ventilation allows the
flight nurse to control FiO₂, PEEP, and minute ventilation, providing more reliable oxygenation
and ventilation. Increasing flow rate on a non-rebreather mask will not significantly improve
oxygenation if the patient is already on 15 L/min.
Question 5
Henry's Law is most relevant to flight nursing when considering which condition?
• A. Decompression sickness
• B. Hypoxia
• C. Hypothermia
• D. Motion sickness
Answer: A. Decompression sickness
Rationale: Henry's Law states that the amount of gas dissolved in a liquid is proportional to the
partial pressure of that gas above the liquid. In flight nursing, this is most relevant to
decompression sickness (DCS), where nitrogen dissolved in tissues forms bubbles as ambient
pressure decreases at altitude. This can occur in crew members during rapid ascent or in
patients transported from hyperbaric environments. Symptoms include joint pain, neurological
deficits, and respiratory distress.
, Question 6
A flight nurse is transporting a patient with a pneumothorax who has a chest tube in place. At
altitude, which finding should the nurse anticipate?
• A. Decreased chest tube output
• B. Increased bubbling in the water seal chamber
• C. Decreased bubbling in the water seal chamber
• D. No change in chest tube function
Answer: B. Increased bubbling in the water seal chamber
Rationale: According to Boyle's Law, trapped air within the pleural space expands at altitude.
This can increase the volume of air being evacuated through the chest tube, leading to
increased bubbling in the water seal chamber. The flight nurse should monitor for signs of
tension pneumothorax and ensure the chest tube remains patent. A flutter valve (Heimlich
valve) or suction may be needed during transport.
Question 7
Which of the following physiological changes occurs at altitude due to the decrease in
barometric pressure?
• A. Increased partial pressure of oxygen
• B. Decreased partial pressure of oxygen
• C. Increased partial pressure of carbon dioxide
• D. No change in gas partial pressures
Answer: B. Decreased partial pressure of oxygen
Rationale: As altitude increases, barometric pressure decreases. This causes a proportional
decrease in the partial pressure of all gases, including oxygen. The decreased PaO₂ leads to
hypoxemia, which can be exacerbated in patients with underlying cardiopulmonary disease. The
flight nurse must anticipate the need for supplemental oxygen and monitor for signs of hypoxia.
Question 8
The gas law that explains the tendency of gases to move from areas of higher pressure to lower
pressure is:
ACTUAL EXAM ALL QUESTIONS AND ANSWERS
ALREADY GRADED A+. 100% VERIFIED
SOLUTIONS | UPDATED PER LATEST
GUIDELINES | GRADED A+
GENERAL PRINCIPLES OF FLIGHT TRANSPORT NURSING PRACTICE
Transport Physiology, Gas Laws, and Altitude Physiology
Question 1
A flight nurse is transporting a patient with a known bowel obstruction at a cabin altitude of
8,000 feet. According to Boyle's Law, which physiological change is the greatest concern?
• A. Decreased oxygen saturation
• B. Expansion of trapped intestinal gas
• C. Increased risk of barotrauma to the lungs
• D. Decreased partial pressure of nitrogen
Answer: B. Expansion of trapped intestinal gas
Rationale: Boyle's Law states that the volume of a gas is inversely proportional to its pressure.
At altitude (decreased atmospheric pressure), trapped gas expands. In a patient with a bowel
obstruction, this can lead to abdominal distention, pain, vomiting, and potential perforation.
The flight nurse must anticipate this and consider nasogastric tube placement before or during
transport. While decreased oxygen saturation (Dalton's Law) is also a concern, the immediate
life-threatening risk from an obstructed bowel is gas expansion.
,Question 2
According to Dalton's Law, which gas is most affected by changes in altitude?
• A. Nitrogen
• B. Carbon dioxide
• C. Oxygen
• D. Carbon monoxide
Answer: C. Oxygen
Rationale: Dalton's Law states that the total pressure of a gas mixture is the sum of the partial
pressures of individual gases. As altitude increases, barometric pressure decreases, and the
partial pressure of oxygen (PaO₂) decreases proportionally. This is why patients may become
hypoxemic during air transport even if they were stable at sea level. While all gases are affected,
oxygen is the most clinically significant.
Question 3
A flight nurse is preparing to transport a patient at a cabin altitude of 10,000 feet. The patient
has a baseline PaO₂ of 70 mmHg on room air at sea level. What is the approximate PaO₂ at this
altitude?
• A. 60 mmHg
• B. 50 mmHg
• C. 40 mmHg
• D. 30 mmHg
Answer: B. 50 mmHg
Rationale: At 10,000 feet, the ambient PaO₂ is approximately 50 mmHg (down from ~100
mmHg at sea level). For a patient with a baseline PaO₂ of 70 mmHg on room air, oxygen
supplementation is almost certainly required during flight. The flight nurse must anticipate the
need for supplemental oxygen and have appropriate delivery devices available. The rule of
thumb is that for every 1,000 feet of altitude gain, oxygen requirements increase significantly.
Question 4
A patient is being transported in a fixed-wing aircraft at 35,000 feet with a cabin altitude of
,8,000 feet. The flight nurse notes the patient's oxygen saturation dropping despite being on a
non-rebreather mask at 15 L/min. Which intervention is most appropriate?
• A. Increase the oxygen flow rate to 20 L/min
• B. Switch to a bag-valve-mask ventilation
• C. Administer positive end-expiratory pressure (PEEP)
• D. Consider intubation and mechanical ventilation
Answer: D. Consider intubation and mechanical ventilation
Rationale: When a patient is hypoxemic despite high-flow oxygen via non-rebreather mask, the
next step is to consider intubation and mechanical ventilation. At altitude, the reduced
barometric pressure makes oxygenation more challenging. Mechanical ventilation allows the
flight nurse to control FiO₂, PEEP, and minute ventilation, providing more reliable oxygenation
and ventilation. Increasing flow rate on a non-rebreather mask will not significantly improve
oxygenation if the patient is already on 15 L/min.
Question 5
Henry's Law is most relevant to flight nursing when considering which condition?
• A. Decompression sickness
• B. Hypoxia
• C. Hypothermia
• D. Motion sickness
Answer: A. Decompression sickness
Rationale: Henry's Law states that the amount of gas dissolved in a liquid is proportional to the
partial pressure of that gas above the liquid. In flight nursing, this is most relevant to
decompression sickness (DCS), where nitrogen dissolved in tissues forms bubbles as ambient
pressure decreases at altitude. This can occur in crew members during rapid ascent or in
patients transported from hyperbaric environments. Symptoms include joint pain, neurological
deficits, and respiratory distress.
, Question 6
A flight nurse is transporting a patient with a pneumothorax who has a chest tube in place. At
altitude, which finding should the nurse anticipate?
• A. Decreased chest tube output
• B. Increased bubbling in the water seal chamber
• C. Decreased bubbling in the water seal chamber
• D. No change in chest tube function
Answer: B. Increased bubbling in the water seal chamber
Rationale: According to Boyle's Law, trapped air within the pleural space expands at altitude.
This can increase the volume of air being evacuated through the chest tube, leading to
increased bubbling in the water seal chamber. The flight nurse should monitor for signs of
tension pneumothorax and ensure the chest tube remains patent. A flutter valve (Heimlich
valve) or suction may be needed during transport.
Question 7
Which of the following physiological changes occurs at altitude due to the decrease in
barometric pressure?
• A. Increased partial pressure of oxygen
• B. Decreased partial pressure of oxygen
• C. Increased partial pressure of carbon dioxide
• D. No change in gas partial pressures
Answer: B. Decreased partial pressure of oxygen
Rationale: As altitude increases, barometric pressure decreases. This causes a proportional
decrease in the partial pressure of all gases, including oxygen. The decreased PaO₂ leads to
hypoxemia, which can be exacerbated in patients with underlying cardiopulmonary disease. The
flight nurse must anticipate the need for supplemental oxygen and monitor for signs of hypoxia.
Question 8
The gas law that explains the tendency of gases to move from areas of higher pressure to lower
pressure is:
