Neonatal Nurse Practitioner Practice Exam

What does compliance specifically measure in a respiratory setting?

1. Change in pressure divided by change in flow

2. Change in volume divided by change in pressure

3. Volume per unit of tidal volume

4. Resistance to airflow within the airway

The correct answer is: Change in volume divided by change in pressure

Compliance specifically measures the ability of the lungs and thoracic cavity to expand in response to changes in pressure. In a respiratory context, it is defined as the change in volume of the lungs that occurs per unit change in pressure. This relationship is vital in understanding how well the lungs can move air in and out during respiration. When compliance is high, the lungs are able to expand easily with relatively little change in pressure, indicating healthy lung function. Conversely, low compliance means that the lungs are stiffer and require more pressure to achieve the same volume increase, which can be seen in conditions such as pulmonary fibrosis or acute respiratory distress syndrome. In this scenario, the other options don't accurately reflect the specific definition of compliance. The first option refers to another concept related to flow dynamics, while the third option discusses tidal volume without addressing compliance directly. The fourth option focuses on resistance, which is more about airflow dynamics rather than the distensibility of the lung tissue. Therefore, measuring compliance provides crucial insights into pulmonary function and respiratory mechanics.