Author Question: Which of the following lung units would be most prone to air-trapping? a. One with high ... (Read 53 times)

RRMR · **on:** Jul 16, 2018

Which of the following lung units would be most prone to air-trapping?

a. One with high resistance and low compli-ance
b. One with low resistance and low compli-ance
c. One with normal resistance and low com-pliance
d. One with high resistance and high com-pliance

Question 2

What factors contribute to the development of auto-positive end expiratory pressure (PEEP)? 1. High expiratory Raw 2. High inspiratory flows 3. Inadequate expiratory time

a. 1 and 2 only
b. 1 and 3 only
c. 2 and 3 only
d. 1, 2, and 3

akemokai · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

ANS: D
Air-trapping occurs with incomplete emptying of lung units. Lung units prone to air-trapping are those with long-time constants (i.e., with high resistance or high compliance).

Answer to Question 2

ANS: B
By effectively increasing the time constant of the lung, high expiratory resistance prolongs exha-lation to the point at which air trapping begins (Figure 46-21, B). Any shortening of the expira-tory time (Figure 46-21, C) aggravates the problem and increases both distal airway pressure and lung volume (auto-PEEP).