Domiciliary Oxygen Therapy by Dr. Saman Kularathne

Danger of Rebound Hypoxaemia• If you find a patient who is severely hypercapnic due toexcessive oxygen therapy (e.g pH 7.23 Pa CO2 13 PaO2 35)• Do NOT stop oxygen therapy abruptly.• The PaCO 2 is very high which causes low PAO 2 due tothe Alveolar Gas Equation (PAO 2 ≈ PIO 2 –PACO 2 /RER)If suddenly changed to air -- PAO2 = 20 – 16.2 = 4 kPalower)( PaO2 will be evenIt is safest to step down to 35% oxygen if the patient isfully alert or call your Critical Care team arrive to providemechanical ventilation if the patient is drowsy.