A patient exhibits a ventilation-perfusion ratio (V/Q) mismatch in the lungs following pulmonary thromboembolism; which compensatory mechanism is triggered to minimize hypoxemia?

💡 Explanation

Hypoxic pulmonary vasoconstriction (HPV) is triggered because when alveolar oxygen tension decreases due to reduced ventilation relative to perfusion, the pulmonary vessels constrict, thereby diverting blood away from poorly ventilated alveoli to better-ventilated regions. Therefore, this minimizes hypoxemia, rather than increasing cardiac output or systemic vasodilation which would worsen the V/Q mismatch.

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