SOE Paramedic Exam 1 Practice

In COPD with hypoxemia, oxygen targets are intentionally kept lower to prevent worsening CO2 retention. Many COPD patients rely on hypoxic drive rather than CO2 levels to stimulate breathing, so delivering too much oxygen can blunt that drive and raise arterial CO2, leading to hypercapnic respiratory failure. Additionally, high oxygen levels can worsen ventilation-perfusion mismatch by reversing hypoxic pulmonary vasoconstriction, increasing blood flow to poorly ventilated areas and raising CO2 retention.

Keeping SpO2 in the 88–92% range provides enough oxygen for tissues while minimizing the risk of hypercapnia and respiratory failure. This balance is why this range is preferred over higher targets like 95–100% or 97–99%, which can elevate CO2 levels without substantially improving outcomes in COPD with chronic hypoxemia.