18-gauge vs. 20-gauge

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Specializes in PACU, Surgery, Acute Medicine.

I just came off on an ER externship with a preceptor whom I call "The Vein Whisperer." She's the one the other nurses call when they can't get a line in. She taught me a lot and starting IVs doesn't make me nervous anymore. She taught me to always go in with a 18-gauge unless it's completely clearly unreasonable, because you never know when a patient might need to have an MRI with contrast or a blood transfusion, and since those are thicker substances than NS or IVP meds, already having a larger catheter means the patient won't have to get re-stuck. The other day I was starting an IV line as a favor to a different nurse and had all my equipment set up when she walked in the room. She said that I shouldn't use an 18-gauge, I should use a 20-gauge unless the MD has specifically requested otherwise because it's big enough for contrast/blood and it hurts less for the patient.

I'm inclined to go along with my preceptor. I think it's gonna hurt a bit to get an IV start whether it's 18-gauge or 20-gauge, and either way it's only going to hurt for the 5 seconds or so that the needle is in. I wouldn't think the difference between 18 & 20 as far as pain goes would be significant. But I do think there's a big difference between the two when we're talking about the microscopic, as far as having a larger lumen for the blood/contrast to flow through, and decreasing the chances of clogging the catheter. The way my preceptor was talking, it made me think that it was standard to use 18-gauge for blood/contrast, that if we sent someone back with a 20-gauge for a procedure like that, they would automatically get a bigger catheter before the procedure. But she didn't use those words.

So! What do you all do! 18-gauge or 20-gauge? I never had a problem getting the 18-gauges in.

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Specializes in Neuro ICU and Med Surg.

If I can get/or think I can get a 18g I go for it. However if I see that the veins are smaller or they are a hard stick I go with a 20g. A 20g will deffinately support MRI/CT contrast, and blood. So either are acceptable. I would just use my judgement when starting iv's depending on vein size.

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Specializes in Neuro ICU and Med Surg.

As far as pain goes the 18g dosen't hurt anymore than a 20g. But this is my personal opinion from personal experience with having IV's.

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Specializes in Cardiac, ER.

At my hospital CT wants an 18g in the ac for contrast. If I send a pt with a 20g in the hand they send the pt back to me and ask me call them when the pt has appropriate access. I agree that the pain difference between an 18g and a 20g is negligible. (I'm an ER nurse so I might be a bit biased)

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Specializes in LTC, ER.

everyone gets an 18g.

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Specializes in Tele, M/S, Psych.
I just came off on an ER externship with a preceptor whom I call "The Vein Whisperer."

:chuckleLove it!:chuckle

My motto is the bigger, the better. If you think you can get an 18 in. Go for it. And once you get used to putting in larger catheters, you can put in smaller ones without a problem!

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Specializes in Emergency, Trauma.

Always go with the 18 first....

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Infusion Nurses Society guidelines (based on research) state smallest gauge in the largest vein that will do the job. This is because the smaller the cath the less damage to the intima of the vein. Now, of course, you always have to take into consideration the reason for the IV. A 20 gauge is ok for CT. Unless your institution says otherwise. a 22 gauge works for blood. It didn't used to but the newer cath lumens are larger that the older products. If a patient has something abdominal going on, or a surgical candidate, go for a larger size. IF they are at the tail end of the hospitalization, you can go down to a 22 with no problem.

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Wow, this is really interesting. Our policies say 20g for blood/contrast. We don't even have 18g's on the floor - we either use a 20g or a 22g.

Here's the debate we are having now - CT calls and asks if the pt has a patent 20g. Okay, well, IV contrast is a vesicant. If we are giving vesicant chemo, we have to start a new IV and the chemo has to be given within 15 minutes by the person who started the IV. Sounds like they need to get a nurse down in radiology to handle this stuff, huh? We recently had a guy with horrible compartment syndrome because of a contrast extravasation. Ouch.

http://www.psa.state.pa.us/psa/lib/psa/advisories/v1n3septemer2004/sept2004vol13_article_a_extravasation_of_radiologic_contrast.pdf

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Specializes in Onco, palliative care, PCU, HH, hospice.

On the floor, we transfuse blood through 22ga all the time but a lot of these patients are >65 y/o and are horrible sticks so we count our blessings if we're able to get even a 22 in lol. Of course if it's a patient who is starting to circle the drain we'll put at least a 20 or 18 unless they have nothing left and are going to need a central line. Just use your judgement and go by your facility's policy, plus I know in the ED it's different you never know what's going to happen so I know most ED nurses prefer at least an 18g for that reason.

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Specializes in Oncology.
At my hospital CT wants an 18g in the ac for contrast. If I send a pt with a 20g in the hand they send the pt back to me and ask me call them when the pt has appropriate access. I agree that the pain difference between an 18g and a 20g is negligible. (I'm an ER nurse so I might be a bit biased)

That's kinda funny, cause the nurses that work in radiology are the BEST at IV's here. They'd do the IV themselves. We've actually sent patients there just to get IVs when no one else can get them.

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Specializes in Med Surg/Tele/ER.
everyone gets an 18g.

:yeahthat:

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