Ventilatory response to hypoxemia

Ventilation increases in a curvilinear fashion as PO₂ falls. The data are obtained with PaCO₂ held constant. Under usual circumstances, the increased ventilation associated with hypoxemia results in a drop in PaCO₂, which blunts the ventilatory response. Note that ventilation does not significantly increase until PO₂ is less than 60 mmHg.