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Air Blood Gases
Clinical Audit
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Air Blood Gas Measurement


  1. Gloves
  2. Sharps bin and kidney dish
  3. Air blood gas syringe
  4. Cotton swab and tape
  5. Alcohol wipes


  1. Consent the patient and apply gloves. Warn the patient that procedure may be quite painful.
  2. Clean the site with some alcohol wipes. The most common place for an ABG to be performed is the radial pulse. But if this pulse is weak it can also be done at the brachial artery (medial antecubital fossa), and femoral artery (groin).
  3. With some packaged ABG syringes you must expel the heparin within the syringe first.
  4. To take blood from the radial artery it is best to lie the patients hand on a flat surface with the wrist fof your dominant hand resting on the palmer surface of their hand, and their hand slightly extended (see this picture). This prevents them jerking their hand in pain when you puncture the skin. Find their pulse with one finger of your non-dominant hand. With your dominant hand hold the ABG syringe like a dart and puncture the site directly under the pulse (most people continue to feel the pulse whilst they do this).
  5. Keep inserting the needle until it starts to fill up with blood. If you have missed the artery it is possible to withdraw and go in at a slightly different angle - but never withdraw the needle completely and then re-insert as this introduces bacteria in to the artery.
  6. Once you have enough blood (usually less than half of the syringe is sufficient) withdraw completely and tape down the cotton wool. Advise the patient to keep pressing on the area to avoid haematoma
  7. The blood must be brought to a ABG within about 15 minutes or it will clot and the machine will not process it.

Little Known

If a blood sample is needed for standard bloods (e.g. FBC/U+Es) but no veins are visible, then it is possible to use a blue needle and syringe and take a arterial sample. This is slightly more dangerous and more painful but may be occasionally necessary.


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