Question

Emma Norton, aged 26, is admitted to hospital with an acute exacerbation of her COPD. Using your knowledge of the respiratory system and the cardiovascular system , please answer the following questions below. Be sure to clearly label the different parts.

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 placed on oxygen but develops respiratory depression. Explain why Emma stops breathing when she is administered oxygen.

PART C / Emma's COPD has caused pulmonary hypertension and subsequent failure of the right ventricle. What are the roles of venous pressure and capillary hydrostatic pressure in causing edema?

PART D /  Emma's right ventricular failure has caused a decrease in cardiac output. Explain which hormonal system will be activated and how it compensate for this.

Answer 1

COPD means chronic obstructive pulmonary disease in which patient experiences difficulty in breathing due to the blockage in the air passage.

1. The total lung capacity (TLC) means the volume of air which can be filled in the lungs after the maximum inspiration.

FVC means forced vital capacity in which the vital capacity is measured after a forced maximum expiration.

FEV1 - means the amount of air exhaled in first one second of time.

In COPD, the volume of air in lungs remain almost the same but the rate of flow of air is decreased which is measured with FEV1/FVC ratio values. Their normal ratio is 0.8 to 1.0.

The value of FEV1/ FVC is reduced to 0.7 to 0.45.

2. Due to the too much blockage in the lungs

( bronchioles) causes difficulty in breathing. Even when the patient is administered To oxygen the patient may develop carbon dioxide retention which leads to further more difficulty in breathing.

The administration of oxygen in COPD patients has to be very careful because in this case the the flow rate of air is affected. In COPD, the alveoli affected where the exchange of gases takes place, so when the oxygen is administered, the exchange of Co2 does not takes place properly and the amount of carbon dioxide increases in the bloodstream.