Correct way to draw blood?

  1. I will start off saying I am not trying to find fault with any nurse, but I and my sisters (Which are RNs as well) have never done this, so just trying to figure something out,lol

    Father has lengthy cardiac and now kidney issues, just admitted to the hospital because Potassium was low (2.6) and he had a great deal of fluid build up. So taking the poitassium horse size pills and I think by my IV as well. As well IV Lasix. When they drew his blood they did it via his IV.....I have never done that, neither have my sisters, so found that odd. And right away his K went from 2.6 to 4 and the blood draw after that was 5.0. But the last 1 it was back at 2.9. I was always taught to never draw blood from an IV,I know it was policy that we could only do it from a PICC line the last unit I worked on (Now occupational health, so no more IVS for me,lol)

    So do you normally draw blood from an IV? And I wonder if that could possibly give a psuedohyperkalemia reading? Ty
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  2. 18 Comments

  3. by   klone
    Was this the same IV from which he was receiving K-Riders?
  4. by   Flames9_RN
    My sister just confirmed...he only got the pills. At 1 time they were going to give it to him via IV, but stayed with the pills. I still think they had to be false readings to go up so quickly.
  5. by   meanmaryjean
    Hemolysis from drawing out of an IV (vacuum pressure and all)
  6. by   brownbook
    Quote from meanmaryjean
    Hemolysis from drawing out of an IV (vacuum pressure and all)
    I agree, except every lab I've sent blood work to will inform me if the specimen is hemolyzed and will have to be redrawn?
  7. by   meanmaryjean
    Quote from brownbook
    I agree, except every lab I've sent blood work to will inform me if the specimen is hemolyzed and will have to be redrawn?
    I dunno- "Your specimen is hemolyzed" seemed to be the default setting some nights!
  8. by   jodispamodi
    Depends on facility policy and patient physiology, some places do allow you to draw off IV (I've never woked anwhere that allowed that but I know others who have), In rare cases if the patient has poor access but a good IV docs may allow draw off the IV as thd best chance of getting a sample. As far as the labwork, how long between the low to high to low, it very possible the K+ replacement brought him up that high but with diuresis from the lasix could have easily dropped him down again, I've seen patients with K+ all over the place and we draw usually 12 hrs to 24hrs, so the lab results may have been very accurate.
  9. by   Flames9_RN
    Quote from jodispamodi
    Depends on facility policy and patient physiology, some places do allow you to draw off IV (I've never woked anwhere that allowed that but I know others who have), In rare cases if the patient has poor access but a good IV docs may allow draw off the IV as thd best chance of getting a sample. As far as the labwork, how long between the low to high to low, it very possible the K+ replacement brought him up that high but with diuresis from the lasix could have easily dropped him down again, I've seen patients with K+ all over the place and we draw usually 12 hrs to 24hrs, so the lab results may have been very accurate.
    JAN 9:
    4 pm: 2.7
    9 pm: 4.0

    Jan 10
    930 am: 5.0

    Jan 11
    10 am: 2.8
  10. by   akulahawkRN
    I would have to say that it sounds like he got some PO replacement and his potassium level went up and they may have continued to give him lasix and the like and held the PO replacement for a short while due to his potassium level quickly rising to 5. Another possibility is that he may have been getting some additional potassium through the IV if the fluid used was something like LR or a similar fluid.

    As to drawing blood samples off of an IV line, where I'm at, we can do it for basic labs but we have to waste 5 mL of blood before we can draw the sample. A running line is disconnected during this to prevent any IV fluid sneaking into the sample. You also have to know what labs are being drawn and what's going through the line. Some labs just cannot be drawn from certain lines if certain medications have been running as the sample will be contaminated regardless of how much waste blood you pull first.
  11. by   Wuzzie
    Quote from akulahawkRN
    I would have to say that it sounds like he got some PO replacement and his potassium level went up and they may have continued to give him lasix and the like and held the PO replacement for a short while due to his potassium level quickly rising to 5. Another possibility is that he may have been getting some additional potassium through the IV if the fluid used was something like LR or a similar fluid.

    As to drawing blood samples off of an IV line, where I'm at, we can do it for basic labs but we have to waste 5 mL of blood before we can draw the sample. A running line is disconnected during this to prevent any IV fluid sneaking into the sample. You also have to know what labs are being drawn and what's going through the line. Some labs just cannot be drawn from certain lines if certain medications have been running as the sample will be contaminated regardless of how much waste blood you pull first.
    I have to agree with this. I don't think the variances in results had anything to do with the draw. Due to the patient population I work with we draw off IVs all the time and have very little hemolysis. Chasing potassium isn't all that unusual. Especially with a patient on Lasix.
  12. by   MunoRN
    Drawing labs off of a peripheral IV is actually recommended practice by the Infusion Nursing Society. You certainly need to take into account what has being going through the IV, and preferably use a dedicated peripheral for draws, but generally it's not a prohibitively bad practice.
  13. by   UrbanHealthRN
    I work in pediatrics, so slightly different patient population, but I remember frequently drawing off of IVs when I worked in the hospital. Like others have mentioned, you do need to be aware of what's been happening to the IV before you draw off it (saline locked? fluids or meds infusing?). Wasting a certain amount of blood before collecting a sample was also helpful in ensuring an accurate specimen, as well as using a slow and steady drawing technique that could help a) not blow the IV and b) potentially reduce hemolysis. At least with kids, we hate to stick them a lot, and the wee ones especially can be tough sticks, so IVs were a huge help.
  14. by   KelRN215
    Quote from UrbanHealthRN
    I work in pediatrics, so slightly different patient population, but I remember frequently drawing off of IVs when I worked in the hospital. Like others have mentioned, you do need to be aware of what's been happening to the IV before you draw off it (saline locked? fluids or meds infusing?). Wasting a certain amount of blood before collecting a sample was also helpful in ensuring an accurate specimen, as well as using a slow and steady drawing technique that could help a) not blow the IV and b) potentially reduce hemolysis. At least with kids, we hate to stick them a lot, and the wee ones especially can be tough sticks, so IVs were a huge help.
    We had some kids when I worked in the hospital who had IVs specifically for the purpose of drawing blood from them. Not often because usually a peripheral IV wouldn't last through repeated blood draws but we did do it from time to time.

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