Blood gases

  1. Hello

    I am very confused about blood gases. Trying to write an essay at the moment, the patient was hypovolemic the ph was 7.38 co2 2.15 po2 28.8 on 15 litres of o2, hc03 12.8 bevt 14.5.

    is this a metabolic acidosis with respiratory compensation and why.

    Thanks
    Julie
    Last edit by julie_hills on Dec 15, '06 : Reason: mistake
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  2. 7 Comments

  3. by   cardiacRN2006
    Quote from julie_hills
    Hello

    I am very confused about blood gases. Trying to write an essay at the moment, the patient was hypovolemic the ph was 7.3 co2 2.15 po2 28.8 on 15 litres of o2, hc03 12.8 bevt 14.5.

    is this a metabolic acidosis with respiratory compensation and why.

    Thanks
    Julie

    The CO2 was 2.5???? Do you mean 21.5?

    C02- base (resp)
    HCO3- acid (met)
    pH - acid

    I was always taught to see which ones matched to know what they are in. So the pH and the Bicarb match. The bicarb is the metabolic component and the CO2 is the resp component. So the metabolic matches the pH (both are acidic) so then they are in a Met acidosic with part resp compensation.

    First off, his PO2 is awful! He needs a vent starting with a FiO2 of 100%! He was is metabolic acidosis, and trying to blow off as much CO2 as possible to compensate. So he should have been hyperventilating. But he was only in a partial compensation, because his pH was not corrected yet. Dude needs some bicarb too before they turn down his rate on the vent!

    But, with a PO2 of 28, his priority is oxygenation.
  4. by   julie_hills
    the co2 and o2 are measured in kPa and and the hc03 in mmol/l. With the reference range i have i make her to have a normal ph, low co2 and high oygen levels. Her bicarb is low and her base excess -15.8
    Last edit by julie_hills on Dec 15, '06
  5. by   cardiacRN2006
    Hmmm...I don't know how that translates!
  6. by   julie_hills
    I make her to have a normal ph a low co2 a high 02, low bicarb and a -15 base excess
  7. by   live_crow
    Your Patient
    ph was 7.38
    co2 2.15 kPa = 16.34mmHg
    po2 28.8 kPa = 219mmHg
    hc03 12.8 mmol/L = 12.8 mEq/L
    bevt 14.5


    Normal
    pH = 7.35-7.45
    CO2 = 35-45 mmHg (4.6 – 5.9 kPa)
    O2 = 75-100mmHg (9.8 – 13.16 kPa)
    HCO3 = 22-26 mmol/L (or mEq/L)
    Base excess = -2 - +2 mmol/L (or mEq/L)

    ** [kPa x 7.6 = mmHg] or [mmHg / 7.6 = kPa]**

    So evaluate your patient’s numbers.
    1.Is he acidotic/alkalotic? -> pH is normal, lower end of normal (towards acidotic)
    2.Is his CO2 normal? -> No, it is very low, or alkalotic
    3.Is his HCO3 normal? -> No, it is very low, or acidotic.
    4.Is his base excess normal? -> No, it is very low, showing a large amount of base must be added to restore a normal pH.

    Because your bicarb and pH have moved in the same direction (towards acidosis), you would say you have a metabolic acidosis.

    Because your CO2 is moving in the opposite direction (towards alkalosis), you know you have respiratory compensation.

    Because your pH is normal, you don't technically have metabolic acidosis anymore. You have a compensated metabolic acidosis (with compensatory respiratory alkalosis).

    Your primary treatment goal is to increase the bicarbonate level, and the CO2 will adjust.

    You don't say why he is hypovolemic - this may be because he was vomiting a lot (losing acid) or bleeding a lot etc.
    Last edit by live_crow on Dec 15, '06
  8. by   bill4745
    What country are you from? Are these metric ABG results?
  9. by   MeryMellen
    .....
    Last edit by MeryMellen on Dec 16, '06

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