Question

emma Norton, 26 is admitted to hospital with acute exacerbation of her COPD

Part A

Emma undergoes a pulmonary lung function test. How would her total lung capacity test and her fev1/fvc values compare to normal physiological values

Part B

In hospital Emma is place on oxygen but develops respiratory depression. Explain why Emma stops breathing when she is administered oxygen?

Answer 1

Answer:

A. COPD is an obstructive lung disease which comprises both Emphysema and Chronic Bronchitis. COPD patients have decreased ability of exhalation. So there lungs appear inflated.

The ratio of Forced Expiratory Volume in 1 sec to Forced Vital Capacity is less than normal (Normal-80%).

Total lung capacity would increase as there will be more residual volume due to decreased ability of exhalation in COPD patients.

Therefore, FEV1/FVC in COPD is less than normal physiological value.

B. Emma suffers from acute exacerbation of COPD. In this case, since there is greatly decreased ability of lung to exhale due to blocked airway by mucus. Now if we administer oxygen supply to such patient without proper surveillance, then due to increased oxygen, more carbon-dioxide would be produced. This carbon-dioxide would not be exhaled due to blocked airway. Consequently, there will be rise in carbon-dioxide level in blood. This results in hypercapnia leading to dizziness, drowsiness, exacerbation of dyspnoea, respiratory depression and ultimately death.