Resp Obstructive

Question 1

1. Increase RV,FRC & TLC
2. Decreased FVC & Very decreased FEV1
3. FEV1/FVC

Answer 1

Obstructive picture

Question 2

In obstructive disease
Flow-volume loop (airflow on the y axis lung volume on the x axis)

Answer 2

The residual volume is increased while the total vital capacity is normal or increased, the loop will typically show a shift to the left.

Question 3

In obstructive disease how is the V/Q ratio kept constant?

Answer 3

the V/Q ratio constant, as the ventilation decreases, the pulmonary vessels start to constrict in order to reduce perfusion to the areas that do not participate in gas exchange

Question 4

What causes chronic Bronchitis ?

Answer 4

Hyperplasia & Hypertrophy of the mucinous glands

Question 5

If the FEV1 doesn’t increase by > 12% after the bronchodilator, then what is the likely diagnosis?

Answer 5

COPD

Question 6

What is the normal respiratory drive how is it different in COPD

Answer 6

Normally senses CO2 (in medulla)
in COPD senses O2(carotids )

Question 7

what causes pulsus paradoxus, ( drop in S bp >10 during inspiration).

Answer 7

-decrease in cardiac stroke volume with inspiration due to greatly increased LV afterload. This is caused by the dramatic increase in negative intrapleural and transmural pressure in someone struggling to breathe against significant airway obstruction.