Certified Transport Registered Nurse Certification Practice Exam

Which gas law is fundamental for the operation of CPAP and BiPAP machines?

1. Graham's Law

2. Boyle's Law

3. Charles' Law

4. Henry's Law

The correct answer is: Henry's Law

The principle underlying the operation of CPAP (Continuous Positive Airway Pressure) and BiPAP (Bilevel Positive Airway Pressure) machines relates specifically to how gases behave under pressure, which is best described by Boyle's Law. This law states that at a constant temperature, the pressure of a gas is inversely proportional to its volume. In the context of CPAP and BiPAP machines, they function by delivering a constant pressure of air to keep the airways open, effectively increasing the lung volume and preventing the collapse during sleep. Understanding Boyle's Law is essential for recognizing how these machines manipulate airflow and pressure to assist patients with breathing difficulties, especially those suffering from conditions like obstructive sleep apnea. Hitting the right pressure is crucial for the efficacy of these devices, hence the relevance of Boyle's Law in their operation. While Henry's Law addresses the solubility of gases in liquids under various pressures, it does not relate directly to the mechanics by which CPAP and BiPAP operate. The other gas laws, such as Graham's and Charles', focus on different gas behaviors and wouldn't directly impact the functioning of these respiratory devices in the manner Boyle's Law does.