PULMONARY PHYSIOLOGY-VQ MISMATCH

SUMMARY

1. Decreased V/Q Ratio (decreased ventilation or increased perfusion): chronic bronchitis, COPD, mucus plugs, pulmonary edema impair the ventilation & decrease the ratio of ventilation to perfusion.

2. Increased V/Q Ratio (icreased ventilation or decreased perfusion): decreased perfusion in PE or increased ventilation in emphysema (large bullae in the lungs), the surface area available for gas exchange is decreased, which causes higher ventilation in comparison to perfusion leading to a high V/Q ratio.

Reference(s)

Wilkinson, I., Furmedge, D. and Sinharay, R. (2017). Oxford handbook of clinical medicine. Oxford: Oxford University Press. Get it on Amazon.
Feather, A., Randall, D. and Waterhouse, M. (2020). Kumar And Clark’s Clinical Medicine. 10th ed. S.L.: Elsevier Health Sciences. Get it on Amazon.
Hannaman, R. A., Bullock, L., Hatchell, C. A., & Yoffe, M. (2016). Internal medicine review core curriculum, 2017-2018. CO Springs, CO: MedStudy.
Therapeutic Guidelines. Melbourne: Therapeutic Guidelines Limited. https://www.tg.org.au [Accessed 2021].