Student Nurse Laura

Orem – "creative effort of one human being to help another human being."

ABG Interpretation

Posted by Laura on April 10, 2010


My 4 Steps to figure out the Patients ABGs

  • If I were to start on the top step going down, I would decide if my patient has acidosis or alkalosis by looking at his pH level. If it is normal but the PCO2 or HCO3- is off, I would keep looking knowing that compensation may have happened.
  • If the PCO2 has an indirect relationship to the pH (if pH is high, but PCO2 is low or if pH is low and PCO2 is high) then I will know the patients condition is Respiratory. (involving the lungs) Either Respiratory Alkalosis or Respiratory Acidosis depending on the pH.
  • If the HCO3- has a direct relationship or is normal (if pH is high, and HCO3- is high, or if pH is low and HCO3- is low), then I know the problem is Metabolic (involving the kidneys). Either Metabolic Acidosis or Alkalosis – dependent upon the abnormal value of the pH.
  • Lastly I would use my bottom step to decide the compensation. Has there been compensation? If the pH is normal, then the body has been working to get it’s pH values back to normal. If it isn’t normal, I would look at the HCO3- for Respiratory (we didn’t look at this one early on for Respiratory), or I would look at PCO2 for Metabolic ( we didn’t look at this one for Metabolic).  – Generally, if all values are off: you have partial compensation (the body is still trying to compensate).

2 Responses to “ABG Interpretation”

  1. Zahid Hussain said


  2. myrtebelle said

    this is really helpful! thank you for posting

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