ventilation-perfusion mismatch
Pronunciation: ven-tl-AY-shuhn per-FYOO-zhuhn MIS-mach
Imbalance between alveolar ventilation and pulmonary blood flow, leading to impaired gas exchange.
Full Definition
Ventilation-perfusion (V/Q) mismatch occurs when there is an imbalance between alveolar ventilation (airflow) and pulmonary perfusion (blood flow) in different regions of the lung, resulting in inefficient gas exchange. In healthy lungs, ventilation and perfusion are closely matched to optimize oxygen uptake and carbon dioxide elimination. V/Q mismatch can manifest as areas of high V/Q ratio (ventilation without perfusion, creating dead space) or low V/Q ratio (perfusion without ventilation, creating shunt). Common causes in pediatric patients include pneumonia, atelectasis, pulmonary embolism, or congenital heart disease. This mismatch leads to hypoxemia and may require supplemental oxygen or mechanical ventilation.
Usage
Usage note: Commonly abbreviated as V/Q mismatch in clinical documentation.
In Context
- "The patient's persistent hypoxemia was attributed to significant ventilation-perfusion mismatch secondary to pneumonia." — Pulmonology consultation
- "Nuclear medicine V/Q scanning revealed regional ventilation-perfusion mismatch in the right lower lobe." — Radiology report