Blood Sugar Measurement: Arterial vs Fingertip

  1. I was wondering, is there a significant difference between blood sugar measurements at the finger tip vs sampling from an arterial (or even venous) blood source? If so, which is more reliable and which one should is preferred to base an intervention on? (ex. insulin drip)
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    About Catticus11, RN

    Joined: May '11; Posts: 74; Likes: 12


  3. by   offlabel
  4. by   Catticus11
  5. by   YoutubeTheNP
    It's not common practice to check a glucose with arterial blood, simply because it is harder to gain a sample, and quite unnecessary.

    The venous and finger tip blood you mentioned are one in the same. The most accurate glucose will be the blood from a vein that is sent to the lab. The blood from the finger tip is no less potent, but rather the glucometer may not be as accurate as the lab test. Whenever I have to order an insulin drip or IV insulin push I go by my glucose from the BMP, not the finger stick.
  6. by   Catticus11
    Hi YoutubeTheNP,

    Thank you so much for response and very helpful answer!

    The reason I originally asked was because I had a patient on an insulin gtt requiring hourly blood sugar checks, and my coworkers and I were having a lot of difficulty getting blood from each stick for our glucometers. However, the patient did have an arterial line, and I successfully grabbed blood sugars off there (though more of a hassle). My question is really whether or not that was appropriate considering that my hospital's insulin gtt protocol assumes the RN is going by fingertip glucometer blood sugars. Was the arterial reading sufficient or should I have kept trying with a fingertip?

    I might just be reading too much into this lol.

    Thank you again!
  7. by   YoutubeTheNP
    Physiologically, I can't think of a reason why the arterial glucose would be any different than the venous. It's not like oxygenation of hgb, ya know what I mean?
  8. by   CraigB-RN
    I found a couple of articles that discussed the difference. They discus in venous blood the glucose has been used where in the atrial blood it's still freshly loaded. there is also a difference between capillary and venous blood.

  9. by   Catticus11
    Thank you so much! Very helpful!