Final answer:
The nurse should explain that pleural effusion fluid is not coughed up because it's located in the pleural space outside the lungs. Coughing removes contents from the airways, not from the pleural cavity, thus medical intervention is needed for pleural effusion.
Step-by-step explanation:
The nurse's best answer to why a patient with a pleural effusion isn't coughing up any fluid is: "The fluid in the pleural space is outside the lungs, so coughing won't remove it." This is because the pleural effusion involves fluid accumulation in the intrapleural space, which is not part of the air passages where coughing would have an effect. Coughing typically helps to expel contents from the airways, but in the case of pleural effusion, the fluid is in the pleural cavity, separated from the lung itself by the visceral pleura.
Understanding the mechanics of breathing and the properties of the pleural space is essential for comprehending why pleural fluid is not expelled by coughing. The negative intrapleural pressure and various passive and active forces involved in breathing, along with the lubricating nature of pleural fluid, prevent the interaction between this fluid and the airways. Therefore, pleural effusion requires medical intervention beyond the body's natural coughing mechanism.
The best answer for the nurse to provide is option a) "The fluid in the pleural space is outside the lungs, so coughing won't remove it."
This answer is correct because pleural effusion refers to the buildup of fluid in the space between the lungs and the chest wall, known as the pleural space. Coughing is not an effective way to remove this fluid because it is outside of the lungs and not within the airways.