Do you ever check CBGs by IV rather than capillary?

  1. Dear All,

    I had a mom who was on magnesium sulfate, insulin, D5W, NS as mainline for the mag, Pitocin, and PCN q 4. She received IV labetolol for her HTN. She had two IVs because the insulin drip was not compatible with the PCN (it was according to one drug guide and not according to another? Pharmacy said to just start another IV and run the insulin from there.) She was in labor and was a VBAC. Her blood sugars had to be checked q 1 hr and q15 min when I adjusted her insulin gtt until w/in 70-120 x 2. Additionally, she had q 6 hr PET lab draws. This mom was IOL for PET, possible HELLP, and CHTN. BPs were 170/100s.

    I checked her CBGs through fingersticks, but I was talking to another nurse on ICU. He said when possible he would take it from the IV. When can you do this? I thought the CBGs had to be capillary. Having said that, my gal's fingers were bruised and swollen; she had so many checks. I would love to try another option, but is there one?

    Where do you all check CBGs?

    Thanks,

    Spud
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  2. 12 Comments

  3. by   dawngloves
    I'd be afraid of loosing my line.I guess it depends on your units policy? You would have to tell the lab the gas was venous, not capillary as the values differ.
  4. by   suzanne4
    Most machines that are used on the floor for monitoring blood sugars can use arterial blood, venous blood, and capillary blood. If wanting to use venous blood, best bet is to have an extra IV inserted for that, so that you do not lose your IV.

    CBG also means capillary blood gas.
  5. by   dawngloves
    Ohhh! Then disregard what I said about lab values.
    If you're worried about tearing up fingers from checking blood sugars, you could ask for pediatric lancets.
    When I did burn, we would sometimes use ear lobes to do Accu Checks.
    HTH!
  6. by   babynurselsa
    It is not recommended if you have dextrose infusing through the line. It has always been my understanding that dextrose can adhere to the tubing, this would include your extension set which would give falsely elevated readings. I would not want to take the chance of adjusting my insulin (especially turning it up) based on a false high reading. If you had only NS infusing that would be another issue.
  7. by   RazorbackRN
    Quote from dawngloves
    Ohhh! Then disregard what I said about lab values.
    If you're worried about tearing up fingers from checking blood sugars, you could ask for pediatric lancets.
    When I did burn, we would sometimes use ear lobes to do Accu Checks.
    HTH!
    I thought she meant blood gases, too.

    I work in burn and we take blood from a-lines, piv's, or cap sticks (earlobes, toes, etc) and use in the accucheck machines. We just try to make sure we're consistent with the source, so that the results are skewed.
  8. by   Bethy-lynn
    Whenever we have someone on an insulin gtt, we aim for an a-line.. otherwise we go for capillary...try sometimes lower on the fingers, and on the meat of the hand, near the thumb, or pinch well and aim for the forearm. It's not a good idea to draw blood from your iv's because every time you do, risk introducing bacteria into your lock, also creating a vacuum when pulling back can damage the vein. Lastly, keep in mind that even if you have something thats compatible with insulin, everytime you hang that piggyback, you are bolusing them with whatever is ahead of it in the line, and when its done running (even if you run it in simultaneously), they aren't getting as much as you've programmed because it isn't in the line, and most pumps don't account for this.
  9. by   NurseyBaby'05
    Sometimes if I have to get blood from a central line, I will leave a few drops in the syringe and use it on the glucometer. I have having to stick someone if I don't have to.
  10. by   ICRN2008
    Capillary blood and venous blood differ in their blood glucose content, and as such the reference ranges are not the same. If your POC instrument is calibrated for capillary blood, then you really shouldn't be using venous blood. I suggest that you contact the point-of-care coordinator, lab director or clinical pathologist at your hospital for confirmation of policies and procedures related to glucose testing.
  11. by   ParrotHeadRN
    We use arterial, venous and capillary blood for fingersticks. Our training manual specifically states you can use all three and I'd hate to have to worry about having the glucometer calibrated every time you use a different source, which can vary from BG to BG. If I have a patient on q1h accuchecks, or even more frequently, I really try to use something other than fingersticks because the fingertips get so sore, bruised and swollen. I know I would appreciate that if I were a patient. While using another source may take a little longer, it certainly is worth it in benefit to the patient. And if someone is really edematous and hard to get blood from, even capillary blood, I will use an IV if it's large bore and I know it has good blood return.
  12. by   suzanne4
    Quote from dawngloves
    Ohhh! Then disregard what I said about lab values.
    If you're worried about tearing up fingers from checking blood sugars, you could ask for pediatric lancets.
    When I did burn, we would sometimes use ear lobes to do Accu Checks.
    HTH!
    Exactly, took me a minute to realize that they were talking about blood sugars on an adult and not a baby in NICU.
  13. by   suzanne4
    All of the machines that I have used over the past few years are calibrated to take all three types of blood and nothing needs to be done differently,m whether NICU, PICU, or Adult ICUs, and other type of unit.

    The machines for home are another story, but in the hospital, they can take all three.
  14. by   NurseyBaby'05
    Quote from BSNDec06
    Capillary blood and venous blood differ in their blood glucose content, and as such the reference ranges are not the same. If your POC instrument is calibrated for capillary blood, then you really shouldn't be using venous blood. I suggest that you contact the point-of-care coordinator, lab director or clinical pathologist at your hospital for confirmation of policies and procedures related to glucose testing.
    I know our policies. I also know that the glucometer can be set for capilarry, venous, or arterial blood. Which one do you think I set it to when I check venous blood?

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