Large bore IV's

Rykielz

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This is a serious discussion I'd like some input on.

Recently there's been a lot of discussion from various medics about the appropriate times to use a large bore IV. Some of the obvious responses: trauma, significant hypotension, cardiac arrest, etc. which are all easily justified. But are there other circumstances where a large bore IV is appropriate? Is it against the standard of care to be prophylactic in circumstances such as severe ETOH, STEMI, dyspnea, etc.?
 

NomadicMedic

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Depends on what you consider a large bore. For me, a large bore IV cath is an 18 or better. I rarely use anything bigger than a 20. STEMI and CVA get an 18.
 
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Rykielz

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Large bore is an 18G or bigger where I'm from. Most patients get an 18 or a 20, however, I've been hearing of more and more medics going to 14's and 16's pretty often during the calls I listed above.
 

STXmedic

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14s and 16s are more of an old-school mentality (at least around here). I'll start a 14 or 16 if I expect the patient is going to need a blood infusion in the very near future, or if I'm going to start a pressor. ~90% percent of my patients will get a 20g. Every now and then I'll do 18s. 14s or 16s aren't too common, primarily given for the aforementioned reasons.
 

Shishkabob

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Shoot, we don't even carry 14s aside from needle decompression. Most people get a 20 or 18.

Sure, you'll get nurses who complain about blood and 'not working with a 20g', but that's hogwash and stupid of them. It's not ideal, but a 20g in the hand is better than a 16g that you can't start.



Permissive hypotension, short transport times, etc not being included into the discussion either.
 

ffemt8978

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We don't carry 14's either - our EMS administrator thinks they're "barbaric". Most people get 20's, with a few exceptions. Trauma and pregnancy get 18's, and occasionally will get a 16 for a second IV if indicated.
 

hibiti87

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I normally use 20's and 18's. I cant recall an incident where a 16 was needed by the hospital.

Slightly off topic. I have heard in passing that a NS bolus can delay delivery in pregnancy. Can anyone verify this and perhaps provide an article on it if it is true?

thank you
 

Veneficus

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This is a serious discussion I'd like some input on.

Recently there's been a lot of discussion from various medics about the appropriate times to use a large bore IV. Some of the obvious responses: trauma, significant hypotension, cardiac arrest, etc. which are all easily justified. But are there other circumstances where a large bore IV is appropriate? Is it against the standard of care to be prophylactic in circumstances such as severe ETOH, STEMI, dyspnea, etc.?

Large bore, which I would consider anything bigger than an 18, (some consider 18 large) is really only indicated for large volume infusion or the potential for that.

Having said that, placing a large bore needle requires practice, it is a bit different from the relatively smaller ones and if you don't do it regularly, you will not be able to do it when you need to.

Severe ETOH probably does not need a large bore but if the person is severely dehydrated from it, they may appreciate it.

A lot of people get all upset over large needles mostly out of the psychological impact, not because of the actual insertion.

I have noticed nurses are particularly seem a bit more adverse to large bore peripheral needles, but raise no objections to using a central line instead of a large bore peripheral.

(in my opinion it is caused by allowing emotion to interfere with judgement.)
 

Pavehawk

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If you're using a lock that may make your choice of gage moot. Most locks (not all) will gate down to a 20 gage. If you're worried about giving fluid consider a direct conection to the cath hub unless you know for a fact the locks and extension tubing you use are large enough to allow the flow you're looking for.
 
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Rykielz

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Should these medics that start large bore IV's for less than obvious reasons be disciplined? Could this be construed as mistreatment?
 

ChorusD

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Should these medics that start large bore IV's for less than obvious reasons be disciplined? Could this be construed as mistreatment?

Only if they're using it punitively. For example, starting a 16 on a pt that doesn't need it just because this is the thirty second time you hauled that pt in a week.

It seems a bit much to discipline providers for doing things they were trained to do. What may be less than obvious to you just might be crystal clear for somebody else.
 

abckidsmom

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If you're using a lock that may make your choice of gage moot. Most locks (not all) will gate down to a 20 gage. If you're worried about giving fluid consider a direct conection to the cath hub unless you know for a fact the locks and extension tubing you use are large enough to allow the flow you're looking for.

I notice the difference in gauges in a free-flowing IV, and always have a lock in. When the luer lock connection is open, it's open. It isn't as small as 20, because wide open with a 20 is significantly less than wide open with a 16.
 
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VFlutter

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I notice the difference in gauges in a free-flowing IV, and always have a lock in. When the luer lock connection is open, it's open. It isn't as small as 20, because wide open with a 20 is significantly less than wide open with a 16.

a 20ga max flow is 60ml/min, a 18ga is 105ml/min and 220ml/min with a 16ga. So yes there is a significant difference in flow rates between the various gauges but how often will there be a clinical need for using a 16 over an 18?
 

blindsideflank

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Another consideration is if contrast dye will be used (CT). And drawing blood from something smaller than a 20 is annoying and "may" damage cells, skewing lab values (k+)
 

VFlutter

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Another consideration is if contrast dye will be used (CT). And drawing blood from something smaller than a 20 is annoying and "may" damage cells, skewing lab values (k+)

I have seen them give contrast through a 22 and ideally you should not be drawing blood from an IV.
 
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Veneficus

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I have seen them give contrast through a 22 and ideally you should not be drawing blood from an IV.

The catheter size for ct contrast is govered by the manufacturer rating of its strength.

Not all IV catheters are rated to be used for contrast. Not to say they will fail, only that they are not tested to withstand it,

As well, there may be institutional regulations or events where what could be gained outweighs the risks.
 

NomadicMedic

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The catheter size for ct contrast is govered by the manufacturer rating of its strength.

Not all IV catheters are rated to be used for contrast. Not to say they will fail, only that they are not tested to withstand it,

As well, there may be institutional regulations or events where what could be gained outweighs the risks.

We resotck all of our IV caths from the ED, so that's not an issue for me.

I was "told" several times that contrast had to be given in the AC and through an 18 or better. Two charge nurses and the interventional radiologist pooh poohed that and said, "Dude, get the line you can get. If they need the study right now, we'll use what we've got."
 

Veneficus

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I was "told" several times that contrast had to be given in the AC and through an 18 or better. Two charge nurses and the interventional radiologist pooh poohed that and said, "Dude, get the line you can get. If they need the study right now, we'll use what we've got."

You know how it works, there is what you'd like, and what you really need.

I am sure you also know that some people, always seem to treat every "best practice" as the right vs. wrong way.

Somebody probably over-simplified "You should use an 18 whenever possible" to "you must."
 

Shishkabob

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Slightly off topic. I have heard in passing that a NS bolus can delay delivery in pregnancy. Can anyone verify this and perhaps provide an article on it if it is true?

Increase of fluids, decrease of release of ADH being released by the posterior pituitary leading to the 'side effect' decrease of Oxytocin being released by the posterior pituitary, which leads to a decrease of uterine contractions.
 
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Outbac1

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Most people get a 20 or 18.
Sure, you'll get nurses who complain about blood and 'not working with a 20g', but that's hogwash and stupid of them. It's not ideal, but a 20g in the hand is better than a 16g that you can't start.

I use an awful lot of 20ga compared to 18ga. Probably an 8:1 ratio. I agree with Linuss the 20ga you have beats the one you didn't get. Most pts are going to get some fluids and/or meds thru it. A 20ga is sufficient for either.

I notice though our lock extensions are called "Macro" and the common one at the local hosp. is a "Micro". The difference being the Macro takes 0.8mls volume and the Micro 0.4mls. The actual ga of these I do not know. The Micro appears fairly small. I don't see the point in putting in an 18 ga or larger IV and then hooking a Micro line to it. Yet I see it done at the hosp. by the nurses. They don't seem fazed by it. If I mention it I usually get "Well their going on a pump anyway". Just doesn't seem logical to me.
 
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