Why does the ventilation-perfusion (V/Q) ratio mismatch cause hypoxemia in acute respiratory distress syndrome (ARDS)?

💡 Explanation

V/Q mismatch leads to hypoxemia because alveoli are ventilated but not adequately perfused; this increases the physiological dead space, thereby lowering oxygen uptake into the blood. Therefore, V/Q mismatch explains hypoxemia in ARDS, rather than issues directly impacting hemoglobin affinity or vascular resistance.

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