Certified Transport Registered Nurse Certification Practice Exam

What type of gas is nitric oxide (NO) when used as a treatment in pulmonary applications?

1. An irritant to lung tissue

2. A selective vasodilator of pulmonary circulation

3. A bronchoconstrictor

4. A general anesthetic

The correct answer is: A selective vasodilator of pulmonary circulation

Nitric oxide (NO) is used in pulmonary applications primarily as a selective vasodilator of pulmonary circulation. This property allows nitric oxide to relax and widen the blood vessels in the lungs, improving blood flow to areas of the lung that are well-ventilated and enhancing oxygen delivery to the bloodstream. This mechanism is particularly beneficial in conditions such as pulmonary hypertension or respiratory distress syndrome, where improving pulmonary hemodynamics can lead to better oxygenation and overall patient outcomes. In contrast, the other options suggest actions that do not align with the therapeutic use of nitric oxide in pulmonary contexts. For example, calling it an irritant to lung tissue does not hold true, as nitric oxide is used precisely for its ability to facilitate vascular function without causing tissue damage when administered in controlled doses. Additionally, its role is not that of a bronchoconstrictor, which would narrow the airways and oppose its intended effects, nor is it used as a general anesthetic, as nitric oxide does not induce general anesthesia but rather serves as a targeted treatment for enhancing pulmonary function.