Final answer:
Increased V/Q ratio resulting in dead space ventilation can be caused by conditions such as pulmonary embolism or emphysema. Physiological shunts due to infections or edema and changes in lung compliance or airway resistance also affect the V/Q ratio. These abnormalities lead to reduced gas exchange and impaired oxygenation of the blood.
Step-by-step explanation:
States that increase the ventilation/perfusion (V/Q) ratio are frequently referred to as causing dead space ventilation. In the context of respiratory physiology, dead space indicates areas of the lungs where air is not effectively exchanged with the blood. An increased V/Q ratio signifies that ventilation exceeds perfusion, leading to inefficient gas exchange and potential respiratory compromise.
Common causes of increased V/Q ratio and dead space ventilation include pulmonary embolism, where a clot can obstruct blood flow while leaving air flow unaffected, and conditions that cause overinflection of lung tissue, such as in emphysema, which may decrease the blood flow relative to the air flow. In both anatomical and physiological shunts, the result is a reduction in the effective surface area for gas exchange, leading to insufficient oxygenation of the blood and retention of carbon dioxide.
Physiological shunt can develop when infections or edema affect the lung tissue, obstructing ventilation while leaving perfusion relatively unchanged. This directly impacts the V/Q ratio and has detrimental effects on gas exchange. Alterations in lung compliance and airway resistance, as seen in diseases like fibrosis or asthma, directly affect breathing and may contribute to V/Q mismatch and dead space.