Exam 1 Q 45

[Leah Sawyer]

COPD decreases ventilation? Is that correct? I have always read that COPD would increase respiratory rate… (Question is below, I selected D)
45. Which of the following conditions would most likely result in a high V/Q ratio?

a. Pulmonary embolismcorrect
b. Increased alveolar perfusion
c. Wearing a N95 mask 8hrs/day
d. COPD wrong

V/Q ratio is the ratio of ventilation (V. the amount of air that enters and leaves the alveoli) to perfusion (Q. the amount of blood that flows to the alveolar capillaries). A high V/Q ratio would mean there is increased ventilation or decreased perfusion. A PE is the only condition that would result in this. COPD and wearing a N95 mask would both decrease ventilation.
References:
1. Taffet, G. (2021) Normal Aging. Up to Date.

[Ciera Stitz]

Hi Leah! My understanding is that you are correct in that COPD increases breathing rate, but this is compensatory due to the decreased ventilation. Similar to when a disease decreases cardiac output there is a compensatory increase in HR. It is the body’s way of compensating for the natural decline in ventilation.

[Jonathan Zins]

Good question Leah, Ciera’s explanation is spot on. COPD typically causes low V/Q ratio due to airway obstruction and poor ventilation relative to perfusion. (Some emphysematous regions may have high V/Q, but overall COPD is categorized as a low V/Q condition.)

[Author]

Posts