General Flashcards

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

Answer: Volume expands as pressure decreases

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.

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

Answer: Expansion of intracranial air and worsening ICP

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

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

Answer: Decreased partial pressure of oxygen

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

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

Answer: Inflate with normal saline or use a pressure-regulated cuff

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

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

Answer: 30–60 seconds

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.

Which flight physiology principle explains why sinusitis or ear pain may worsen during aircraft descent?

Answer: Boyle's Law — gas compression in blocked cavities

During descent, atmospheric pressure rises and gas in blocked sinuses or middle ear cannot equalize, compressing trapped air and causing pain or barotrauma.

Which of the following patients poses the GREATEST risk for decompression sickness during air transport?

Answer: A patient who completed SCUBA diving 4 hours ago

Nitrogen bubbles from recent SCUBA diving can expand and cause decompression sickness when cabin altitude increases; standard guidance is to wait 12–24 hours before flying after diving.