pulse oximetry

Discussion in 'Clinical Rotations' started by caffeine37, Dec 13, 2008.

  1. caffeine37

    caffeine37 Senior Member
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    two questions:
    1. how does a pulse ox work?
    2. when can you measure oxygenation with pulse ox and when should you draw ABGs?

    thanks!
     
  2. Hernandez

    Hernandez Paranoid and Crotchety...
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    1) is uses 2 different spectrums of UV light and uses the creates a ratio based off the rates of absorbtion of the 2 UV spectrums to give a percent saturation based off of how much oxyhemoglobin absorbs vs deoxyhemoglobin absorbs.

    2) You obtain 3 pieces of information from ABGs, acid/base status, ventilation (CO2) and oxygenation. However, when you look at what's more important PaO2 vs SaO2, it's actually SaO2 as the equation on oxygen carrying capacity is 1.34xSaO2xHgb + (0.003xPaO2). I don't get an ABG just to see what the PaO2 is when I have a reliable SaO2.
     
  3. EternalMD

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    Just keep in mind it won't work well with CO (overestimated) or metHb (underestimated) nor does it work well if you don't get a good waveform (many reasons why this could be going on --> poor circulation, severely tachycardic patient to name a few).
     

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