05 Hypoxia - Boards and Beyond

  • saturation of hemoglobin depends on PaO2

PaO2

  • in arteriole blood
  • measures dissolved

  • measures saturation

  • saturation of hemoglobin depends on PaO2

Hypoxia

  • hypoxemia: low number calculated from equation
  • hypoxia can be caused by hypoxemia and other things

HF

  • hypoxia or ischemia
  • pulmonary edema with CHF: may have reduced O2 content

Anemia

  • O2 binding capacity reduced
  • not enough Hb around

CO

  • functional anemia: taking Hb away from O2

Alveolar Gas

  • PAO2: O2 partial pressure in alveoli, lower because O2 exchange
  • PaO2: lower because mixing of blood from vessels travel through lungs and do not go through alveoli

  • gas exchange

  • high altitude: low partial pressure of O2