CFRN General 2

Question 1

According to Boyle's Law, what happens to a gas-filled space (e.g., pneumothorax) as aircraft altitude increases?

Accepted Answer

Volume expands as pressure decreases

Answer

Boyle's Law states that at constant temperature, gas volume is inversely proportional to pressure, so trapped gas expands as altitude increases and atmospheric pressure falls.

Question 2

A flight nurse is transporting a patient with a closed head injury. Which altitude-related concern is MOST critical?

Accepted Answer

Expansion of intracranial air and worsening ICP

Answer

Trapped intracranial air expands at altitude per Boyle's Law, increasing intracranial pressure and potentially worsening herniation in head-injured patients.

Question 3

What is the primary cause of hypoxia experienced by flight crew and patients at altitude without supplemental oxygen?

Accepted Answer

Decreased partial pressure of oxygen

Answer

As altitude increases, barometric pressure drops, reducing the partial pressure of oxygen (PaO2) in inspired air even though the percentage of oxygen remains 21%.

Question 4

During air transport, a patient's endotracheal tube cuff is inflated with air. What is the recommended management?

Accepted Answer

Inflate with normal saline or use a pressure-regulated cuff

Answer

ETT cuffs inflated with air expand at altitude, potentially causing tracheal ischemia; filling with saline or using a pressure regulator maintains consistent cuff pressure.

Question 5

A CFRN is assessing a patient for potential time of useful consciousness (TUC) after cabin decompression. At 25,000 feet, TUC is approximately:

Accepted Answer

30–60 seconds

Answer

At 25,000 feet the TUC is approximately 3–5 minutes; at 35,000+ feet it drops to 30–60 seconds, requiring immediate oxygen supplementation.

CFRN - Certified Flight Registered Nurse Practice Test

CFRN - Certified Flight Registered Nurse Practice Test

CFRN General 2