Correct way to draw blood?

[Flames9_RN]

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

[KelRN215, BSN, RN]

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.

[greenerpastures]

Is it an IV, or a midline that sometimes looks like a peripheral IV? We can draw blood from midlines, but you'd never know it was a midline unless you looked closely at the tubing. It would look like we were drawing out of a regular IV.

[FurBabyMom, MSN, RN]

When I worked floor/stepdown, we were allowed to draw labs off an IV start before we ran anything and usually after you inserted the catheter but before you connected the pigtail tubing. Alternatively, we were allowed to draw off a midline, PICC or CVC of any kind provided we'd been checked off on the accessing requirements. We had a lot of patients come to use from surg/trauma or neuro ICU and those usually had a temporary central line. Central lines or PICC lines made lab draws for mannitol or heparin administration so much easier. We really liked our PICCs and CVCs for things that were vesicants...not that you don't have to worry at all but there is a lower likelihood of issues there.

Being in the OR now, it's a little different. Almost all of my patients get either an arterial line or a central line (really big, treacherous cases get both). Anesthesia can draw labs off either. No additional stick required, though our patients wouldn't know the difference.

I will say, I was a patient in my facility's ED earlier this year. They drew my labs off my IV before they connected the 6" tubing section. If I recall, that's what our policy says.

Regarding hemolysis of drawing labs through a peripheral IV, I never considered that as the reason. I was always taught that you couldn't do it if the medication you're testing levels for was run through that line you couldn't use it because of the potential to draw back some of the medication perhaps still in the tubing. Also, most peripheral stick sets for venipuncture - butterfly devices, what have you, are 23g or 25g. Most IVs and IV tubings are a larger bore gauge than those devices. Is there something I'm missing here? Maybe it's been too long since I've been a floor nurse...

[akulahawkRN, ADN, RN, EMT-P]

...I was a patient in my facility's ED earlier this year. They drew my labs off my IV before they connected the 6" tubing section...

As an ED RN, I do this all the time. What helps this happen is our phlebotomists from the lab usually show up in the patient's room at about the time I'm about to start a line. If I'm successful with the first stick (I usually am) then I do the draw for them right off the catheter and the patient doesn't need to be stuck another time.

[Flames9_RN, BSN, RN, EMT-B]

Thanks for all the input all..appreciate it...ty

[phoebe2020, BSN, RN]

Where I work, you can only take blood from IVs during the first 24 hours it has been placed. After that, you need to stick 'em.

As long as you're flushing the IV first, and then wasting the first lot, you should be getting an accurate reading.

[Buckeye.nurse]

We use PIVs to draw labs if possible to avoid additional sticks on our patients. I work on a hematology oncology floor, so our patient population generally have poor veins, and are thrombocytopenic. Usual practice is to flush the line, then waste 5 ml's before obtaining the specimen. Potential exceptions are situations where a patient has a heparin gtt running, and we are drawing a PTT to monitor the infusion rate. Generally in that situation, I will do a peripheral stick from the opposite arm to ensure the specimen is correct. Also, we never draw blood cultures off a peripheral line. As with all things, know your policy/procedures as every hospital/institution is a bit different. Hope this helps!