Which best explains the mechanism by which gas exchange is impaired in pulmonary contusion?

Prepare for the Prehospital Trauma Life Support (PHTLS) exam. Access diverse quizzes and multiple-choice questions, each with hints and comprehensive explanations. Enhance your readiness and confidence for the PHTLS certification exam!

Multiple Choice

Which best explains the mechanism by which gas exchange is impaired in pulmonary contusion?

Gas exchange is impaired in pulmonary contusion mainly because the capillary-alveolar membrane is injured and blood leaks into the alveoli. This alveolar flooding, along with interstitial edema, fills air spaces with blood and fluid, reducing the surface area available for oxygen to move into the blood and creating shunt-like blood flow through nonventilated units. The result is a marked ventilation-perfusion mismatch and hypoxemia. While atelectasis from edema or compression of lung tissue can worsen gas exchange, the direct mechanism that best explains the impairment is blood in the alveoli. Obstruction of the bronchi is not the typical driver in this injury.

Gas exchange is impaired in pulmonary contusion mainly because the capillary-alveolar membrane is injured and blood leaks into the alveoli. This alveolar flooding, along with interstitial edema, fills air spaces with blood and fluid, reducing the surface area available for oxygen to move into the blood and creating shunt-like blood flow through nonventilated units. The result is a marked ventilation-perfusion mismatch and hypoxemia. While atelectasis from edema or compression of lung tissue can worsen gas exchange, the direct mechanism that best explains the impairment is blood in the alveoli. Obstruction of the bronchi is not the typical driver in this injury.

More practice questions