Electron Transport Chain & ATP Synthase | USMLE Step 1
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A 34-year-old woman is rescued from a smoke-filled apartment. She is confused and has soot around her mouth but no major cutaneous burns. Blood pressure is 88/54 mm Hg. Oxygen and intravenous fluids are started. On supplemental oxygen, her arterial oxygen tension is 286 mm Hg, but plasma lactate is 13.6 mmol/L (reference 0.5–2.2). The emergency physician suspects an inhaled toxin is impairing cellular oxygen use.