Ok, something came up today that got me to wondering... is there a rationale for using a smaller angiocath than possible when starting an IV on a patient?
I mean, back in my Paramedic days, we didn't start anything smaller than a 16 antecubital and tried really hard to get an 18 in even for hands if we at all could, because we had no clue what kind of fluids the patient would end up needing, and I was taught that blood products needed at least an 18. Ok, so I've since been educated that blood products *can* use a 20, but an 18 is preferable. And I'm not calling for 14 and 16 in regular use.
But.
Last night the nurse knew my pt needed a unit of PBRC and it would be coming on my shift. The existing IV (an 18) she said was leaking, so she put a 20 in so I'd have it for the PBRC. As a new nurse, I asked around (supervisor, other ICU nurse on duty) and the consensus was that if I could get an 18 in, that would be preferable. Pt had decent veins and I had no trouble starting an 18. (I'm in an LTAC ICU)
So, it got me to thinking... the only nurses I have seen routinely use 18's are ICU and ER/Trauma nurses. Everyone else seems married to 20's and 22's. Is there a rationale for using less than an 18 if you can get an 18 in and assuming there's no expectation of administering blood? (I fully recognize there are lots of patients that you're lucky to get a 22 in, and those aren't the ones I'm talking about.) Or is it that the larger angiocaths scare a lot of nurses for some reason?
I've tried to search my references and even Google for it, and haven't found much of any help. All I've really found is that 20 is the minimum for blood, and 18 is preferred.
PSU_213, our CT machines require a 20 or larger in the AC. It has nothing to do with the tech at my hospital. They simply are not allowed to do a CT without a 20g A/C; something about the pressure/machine itself.
I really think that comes down to policy, not what is possible, because the peds world pretty much discredits all "you need a big whatever to do this procedure/you can't do X with something that small." In the teeny tinies, we've absolutely sent kids to CT with 24s, although the CT department prefers at least a 22.
And if they already have a 20 in and need blood...not going to stick them again. More work for me more sticking the pt, lose-lose situation, imo! As a funny aside, when I was in practicum, my preceptor trained me to use 18s whenever possible because they may need a CT with contrast, and that dye can't go in a smaller than an 18....still no idea where that came from, I send pts to CT with contrast all the time with just a 20, never been an issue.[/quote']
It is not that the dye can't go through, it is the pressure that the infuser puts on the catheter when it injects the dye. A 20 or larger is acceptable, smaller gauges can cause malfunctions which mess up the CT.
This is the same reason you must have a special central line in place if you want to use it for CT, the dye injector masses a huge amount of pressure and can potentially blow the cannula.
Ok, and flame retardant suit here, but it's a little melodramatic to say that putting an 18 gauge in a patient that needs IV treatment is unnecessarily invasive. The patient needs an IV, and an 18 gauge is an appropriate size for clinical use. It's not like she busted out a 14 for the heck of it. I got the impression from the post that the IV still needed to be started and she just upgraded the size... Which is within a nurses judgment to do. It may not be necessary, it may not be the best call but let's keep our feet on the floor:).
Specializes in burn ICU, SICU, ER, Trauma Rapid Response.
Ok, and flame retardant suit here, but it's a little melodramatic to say that putting an 18 gauge in a patient that needs IV treatment is unnecessarily invasive. The patient needs an IV, and an 18 gauge is an appropriate size for clinical use. It's not like she busted out a 14 for the heck of it. I got the impression from the post that the IV still needed to be started and she just upgraded the size... Which is within a nurses judgment to do. It may not be necessary, it may not be the best call but let's keep our feet on the floor:).
*** If I remember right the situation was the previous shift nurse had placed a brand new 20ga for administration of blood. The oncoming nursing felt an 18ga was better and placed a new 18ga in spite of the new 20ga already inserted. That would be unnecessarily invasive.
If placing a initial IV for blood products then the decision would have to be made what size. In that case an 18ga likely would not be considered overly invasive.
It is not that the dye can't go through, it is the pressure that the infuser puts on the catheter when it injects the dye. A 20 or larger is acceptable, smaller gauges can cause malfunctions which mess up the CT.
This is the same reason you must have a special central line in place if you want to use it for CT, the dye injector masses a huge amount of pressure and can potentially blow the cannula.
Ok, and flame retardant suit here, but it's a little melodramatic to say that putting an 18 gauge in a patient that needs IV treatment is unnecessarily invasive. The patient needs an IV, and an 18 gauge is an appropriate size for clinical use. It's not like she busted out a 14 for the heck of it. I got the impression from the post that the IV still needed to be started and she just upgraded the size... Which is within a nurses judgment to do. It may not be necessary, it may not be the best call but let's keep our feet on the floor:).
the way i read it the other nurse started a 20 gauge and she thought that was inappropriate so she started another iv.
I guess the bottom line is we need to be putting some serious thought into where the IV goes and what size. There is no single answer, it depends on the patient, the diagnosis, the scenario and to some extent the nurse.
I have said this before on another thread, but a patient coming into the resus bays is most likely going to get an 18 in the right AC. If we need to push adenosine that's where it needs to be and for a very fast push size matters. This is an ideal spot for CT, it spares the R wrist for the cath lab, you can run fluids fast, hook up the level 1, and I'm really not that concerned about ADLs at that point. Also I can have the cannula in, all my blood out and the bag infusing in under a minute, no fuss no muss.
Big GI bleed? I'm starting not one, not two but 3 18 or if necessary 20s... I know I'm going to need them.
Yes, we can in a code situation start an IO but by policy you then lose a nurse or NA whose entire job becomes guarding the IO and immobilizing the leg, so the culture in my workplace is to have a good, reliable IV.
If you work on the floor with patients who are up and caring for their own needs your considerations are going to be very different. If I'm starting an IV for home therapy I will, as stated before, use a small gauge in a big vein in a comfortable spot.
If you have a patient who is kind of spazzing about the whole IV thing honestly I would just pick whatever spot you *know* you will get it and avoid hands as they are difficult to immobilize during insertion.
There are so many things that we need to consider, so the educator who told me "if it's not an 18 don't bother" is as wrong as the one who said "never poke the AC unless you have tried everywhere else." There are no hard and fast rules.
We need a minimum of a 20g in order to chest CT with contrast. All other CTs utilizing contrast can go with a 22, just not the chest CT. Where I work, it is policy to have at least a 20g to run blood, otherwise we need a doctor's order to infuse through a 22g.
Kiddos usually get a 24g unless they need to go for a CT with contrast, then we have to get a 22g in them.
Specializes in burn ICU, SICU, ER, Trauma Rapid Response.
Yes, we can in a code situation start an IO but by policy you then lose a nurse or NA whose entire job becomes guarding the IO and immobilizing the leg, so the culture in my workplace is to have a good, reliable IV.
*** It is inappropriate for start a large bore IV when it is unlikely the patient will need fluid recitation. For giving meds and drips smaller is better, especially drips like amioderone, NTG, ditalizem etc. My point with the IO is that we no longer need to place large bore IVs when they are unlikely to be needed "just in case". Obviously a diagnosis like sepsis or GI bleed would mean it is likely that patient will need fluid recitation and a couple large bore IVs should be inserted.
A whole staff person to guard an IO? Really? Immobilize the leg? Really? Why?
For most people I use a 22, simply because they are the easiest to place (shorter in length, too, which is perfect for valves and twisty veins) and quite honestly one can give most everything -- including blood products or fluid boluses -- using a 22.
I do the occasional 20, usually on the bigger veined people, people who are pre-op, or if I'm asked to place one in ICU or ER.
The only time I use an 18 is when CT specifically asks for an 18.
Personally, I usually go with a 20 ga for multiple reasons. We are generally a postop floor and our facility requires a 20 ga or bigger for surgery. We also do lots of CTs. Radiology requires a 20 ga or bigger in the AC for the contrast. In addition, we give lots of abx, especially vancomycin (although our PICC team recommends a central line for such vesicants; the docs won't usually agree to PICCs just for abx though). We once had a pt ordered a PICC for a CT to r/o PE (we were unable to get access in the AC after a K+ cocktail infiltrated). Good call on the doc; she indeed had a PE.
Good to know about using smaller bore for blood. We usually use 20s for that. I never worked in peds though and never thought about it before. Great knowledge for the hard sticks!
For vesicents you want quick hemo-dilution and the smaller the gauge the better More blood flow around the catheter creates more hemo-dilution. Larger bores can sometimes occlude some blood flow. We give chemo through 24s. Also we do CTs through 22s unless it is PE Protocol.
hiddencatRN, BSN, RN
3,408 Posts
I really think that comes down to policy, not what is possible, because the peds world pretty much discredits all "you need a big whatever to do this procedure/you can't do X with something that small." In the teeny tinies, we've absolutely sent kids to CT with 24s, although the CT department prefers at least a 22.