PaO₂ | ABG Interpretation - MedSchool
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ABG Interpretation
 
 
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The PaO₂ is the partial pressure of oxygen dissolved in plasma. This is a marker of the amount of oxygen available to be delivered to tissues, and a reduced PaO₂ is indicative of hypoxia.
 

PaO₂

 
 
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Overview

  • The PaO₂ is the partial pressure of oxygen dissolved in plasma. This is a marker of the amount of oxygen available to be delivered to tissues, and a reduced PaO₂ is indicative of hypoxia.
      • Normal Range

      • 80-100mmHg on room air

Hypoxia

    • Causes of Hypoxia

    • Low Partial Pressure of O₂

    • High altitude
    • Hypoventilation

    • CNS - drugs, trauma, encephalopathy, MND, Guillain-Barré
    • Muscular / neuromuscular - myaesthenia, paralytics, myopathy, fatigue, malnutrition
    • Airway obstruction
    • Decreased compliance
    • Chest wall abnormalities
    • V/Q Mismatch

    • Physiological shunt - atelectasis, pulmonary oedema, pneumonia, ARDS
    • Anatomical shunt - cardiac shunt e.g. tetralogy of Fallot
    • Dead space - asthma, COPD, pulmonary embolus, heart failure
    • Decreased Diffusion Capacity

    • Rare
Last updated on February 7th, 2020
 
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