You determine that a patient's diaphragmatic excursion is 5 cm with the diaphragm at T12 on inspiration and T10 on expiration. This finding

Question

a. is abnormally low, indicating hypoventilation.
b. is normal.
c. indicates a high diaphragm level with displacement possibly by ascites.
d. indicates the presence of atelectasis or pleural effusion in the lower lobes, producing a dull sound on percussion and leading to a false determination of high diaphragm level.

Answer 1

B
Diaphragmatic excursion provides information on the patient's depth of ventilation. This is accomplished by measuring the distance the diaphragm moves during inspiration and expiration. The measured distance for diaphragmatic excursion is normally 3 to 5 cm. The level of the diaphragm on inspiration is T12, and T10 on expiration. A diaphragmatic excursion that is less than 3 cm is abnormal, indicating hypoventilation. Space-occupying states such as ascites will lead to an elevated diaphragm due to the upward displacement of the lungs and diaphragm. If atelectasis or pleural effusion is present in a lower lobe, the diaphragm will seem abnormally high. These conditions are dull to percussion as is the diaphragm. The border between the diaphragm and the dull lung will thus be indistinguishable.