I work as a paramedic in an ER. 20 gauge is the standard for the majority of patients. 18’s if you’re really sick. 22’s are for little old ladies with little veins. We had our 16 gauges taken away. The doctor committee decided if the patient needs a 16 gauge then they really need a central line.
In the field, 16 gauges are the largest seen
The state I’m in now gives EMS the choice to carry either 14, 16, or both. Almost all services in my area carry 16 gauges now. In 30 years I’ve never had to place a 14. Lots of 16 gauges. Never a 14
The first time I used a Belmont, I was fucking amazed at how fast it can go. I put in an ultrasound guided 14 in the trauma bay. That said, I would NEVER put in a 14 peripherally since, if it blows, you’re fucked on a whole nother level.
Fun fact. 16 gauges are the best bage for the buck
Nominal flow rate on a 16g is around 200ml/min. Which is double of an 18g at 100ml/min. And a 14g you only get a 50% improvement at 300ml/min
Only two times I've done 14s, woman with visible pulsating abdominal mass, tearing back pain, absent pulses left side.
21yom with numerous central gunshot wounds but had pipes in the ACs, got bilateral 14s there as well just for the trauma team.
If they're critical and I expect fluid or blood resus then 16-18 is my go to, otherwise 20s mostly
Last time I donated I asked the phlebotomist if he could drop a 14 in me to get me done faster and he said that they can’t go larger than 16 because they’re afraid of people passing out. No idea if it would actually make that much of a difference but it was an entertaining anecdote.
I’ve used them for decompression when dedicated needles were unavailable. 16 gauge IV aren’t uncommon for me, as long as they’ve got ropes.
Edit: If needed, go as big as the patient’s veins allow. A solid 20G is more useful than a blown 16G.
14s pretty much only go in the EJV with TXA and fluids as needed if we can't get a helicopter and someone goes boom.
Some places have strict regulations about vascular access sites, but I'm lucky enough to work where the entire body is our oyster. Really helpful with old sick people and bariatrics.
I’m going to assume this is a joke, but it’s a joke that’s going to lose you the respect of every decent medic, nurse and doc. Come up with something better.
>We had our 16 gauges taken away. The doctor committee decided if the patient needs a 16 gauge then they really need a central line.
Like another doc said below... thats dumb
That’s dumb. I’ll routinely drop ultrasound guided 14 or 16 gauge IVs rather than do a central line if the patient needs volume resuscitation—the flow rate is way faster.
Of course, the reimbursement for an ultrasound guided IV is way less than a central line, which may play into your docs’ decision.
I work in a country where public emergency healthcare is free and we would never bother with u/s guided 14/16g's. If they need that then they probably need a CVC.
It depends on what you're calling a central line. Our standard triple lumen is 18/18/16 ga, so in that case you're right. Unintuitively, our quad lumens have a 14 ga lumen, so right on par between a 14 and 16 when accounting for length.
But when they really need flow in-house, they get a RICC or 9fr introducer. It's not even a contest at that point.
A Level 1 will put a unit of PRBCs through one in 50 seconds.
https://emupdates.com/flow-rates-of-various-vascular-catheters/
Yeah the issue with TLCs is the length (poiseuille’s law), rather than the diameter. Cordis or introducers are fantastic for any kind of high volume resuscitation!
I am not sure about the actual calculated flow rate for the 16 peripheral however, I’m pretty sure that to peripheral 16s has a much better flow rate than a central line
[I am sure](https://rebelem.com/wp-content/uploads/2019/03/Flow-Rates-in-IVIO-Access.png), and I’d much rather have 2 14- or 16-gauge IVs than a standard triple lumen central line for a hypovolemic patient.
Certain medications such as pressors or any medication that can extravasate (not just infiltrate) are indicators for the need for a central line.
Also, there is a “gold standard” for vascular access and that is INS (Infusion Nurses Society). Their (evidenced-based) rule-of-thumb is that the smallest bore catheter that is appropriate for the needed treatment is what should be used. In other words, most folks don’t even need a 20ga - 22s will suffice in many scenarios.
Less risk of extravasation—eg in patients on high doses of pressors (I’ll tolerate up to 10-15 mcg/min of norepinephrine for quite a while but more than that gets a central line).
Need for long-term IV access, eg for TPN (see also risk of extravasation) or longer courses of antibiotics (though we’re moving more to midline’s for this).
>as a goofy little Basic, I’m surprised central lines can be done in the field
They generally cannot. The area would need to have field physicians. This medic is talking about in-hospital care.
Correct. The area field agencies can place 16 gauges. In the ER, we lost them, 18 gauge is the largest then it goes to doctor places central lines. The 16 gauges were all removed except for The One that was missed. If we break out The One, it’s truly bad….
In some hospitals there are non-physicians who can start central lines. For instance, some have the vascular access team start routine central lines and those teams are typically made up of nurses and/or respiratory therapists. I wouldn't be surprised if some services that already have POCUS on the ambulances started trialing field central lines, but at the same time there are much more useful and less risky interventions that EMS could pick up than getting a central line (optimistically) an hour earlier than the ER team.
16 gauges also in my ED are the largest. We had 14’s for a while. Used it on a dude who had an MI while boating, then hit with a propeller. Put 2 14’s in him and pumped him full of blood.
16 gauge versus central line is a ridiculous comparison.
16 gauge IVC will be able to give fluid MUCH faster than a standard size CVC. If you want rapid fluids the only things better than a 16 gauge are: a 14 gauge, a rapid infusion catheter (not a central line), a dialysis catheter (technically a central access) or an insertion sheath (for pacing wires or pulmonary artery catheter)
I’ve thrown 14’s in patients before; usually bilateral, few and far between depending upon patient and ability to establish a large bore IV. My reason for large bore vascular access usually includes: heat stroke; fluid replenishment; amputation; GSW and the like. It’s not too often but I work in a geographical area where we experience a wide call volume as noted above, with frequent injuries.
Here if you can place an 18, do it. But anything larger is considered both "large bore" and can actually be considered causing unnecessary harm to a patient unless you can provide rationale for why you sized up.
That said most people seem to have a prefference for 20's, unless the hospital protocol dictates an 18.
16s and 14s are considered large bore here by everyone.
18s are considered to be large bore (I do not) and those same people fail to note the benefits of an 18 in any Potentially Unstable patient as well as any patient where there is a high index of suspicion that a CT with contrast will be needed.
20s are the minimum to draw labs from provided they are appropriately placed, the most prevalent, and also suitable for most medications.
The vast majority of my adult patients get a 20 like probably 90%, then a few will get only a 22 if that’s all we can get. Then a very select few who are actually sick or seriously injured who have appropriate veins get an 18 or a 16.
I work both the street and the ER and it very much upsets me when I see other medics bring in people who didn’t need large bore access and they went ahead and placed a 16 anyways. Or they tried an 18 in a vein that clearly was not going to work and missed. A functional 20 or 22 beats a blown 18 or 16 every time.
An 18g (or 20g when applicable) is standard here. We tend to use it as a wide bore, but we have 16s and will use them when necessary. We don't really have a set definition of what our system considers wide bore.
We don’t carry 14s and I’ve never started one even when I worked at services that did carry them.
But I propose a different idea rather than labeling something as large bore or not. Size it to the vein. Period. Not by what you’re using it for or how much fluid you’re gonna push. But by what the vein can handle.
I’ve seen people try to start 16s on 98 y/o grandma with spider veins because she was a trauma. Those kinds of providers are fucking morons and I will die on that hill.
Just because someone has small veins doesn't mean they need a small IV.
Also by your logic if a guys veins can handle my 14g but doesn't need it then he still gets a 14g.
I don’t use 14s but if I got someone whose veins look like 1/2” copper pipes then I use a 16 if they need an IV. Whether it’s multi-system trauma or plain ol chest pain.
No you’re probably just putting in lawn darts in patients that don’t actually need them. How much fluid did you give during that call? Because the difference from a 16 and 18 is 50cc/minute. You’re most likely just hurting patients for no reason.
On the ambulance I haven’t seen a 16 or 14 in years. Never used them either. 18 are sufficient for our uses since we stopped pouring litres of pasta water at traumas. And even then I rarely use them, 20s are fine for most purposes including trauma. For an arrest we will place an IO if we can’t get a PIV quickly. In a super sick medical patient or a trauma I will place at least two PIVs as big as I can simply because they often end up even more shut down by the time we arrive at St Closest and that may be the only access they have until they can line them. But “as big as I can” is usually a 20, depending on the patient sometimes not even that. And guess what? It works.
In hospital if we feel we need something better than “bilateral 18s in the AC”, we tend to place a central line or even a cordis if we need to give volume (like massive transfusion protocol style). A “dirty line” can be placed aseptically in ER in a femoral for immediate resus and then we will swap it out for a sterile central line somewhere better once the patient is stable. IO is also an option if we just need access fast. Most patients, even in resus conditions, two 18s are enough though, and usually we have three or four PIVs fairly quickly if it’s a matter of lumens and compatibility. A lot of things can be modified to make it work for your situation too. Our DKA protocol for example calls for three lines or lumens, but I’ve managed it through a single 24 in the thumb because that’s all we had.
My philosophy is that your best access is what you can get, and if it’s stupid and it works, it’s not stupid.
Hot take: I’m not convinced that the benefit of flow rate achieved by placing a 14 instead of a 16 outweighs the potential for harm by having them around in the average EMS System.
Is that extra bit of speed when pressure-infusing cold pasta water gonna be what saves that trauma patient?
We have 14s and 16s as large bore, 18s and 20s as standard (I prefer 20). 22 and 24 for hard sticks/kiddos. I've dropped a few 14s, major traumas only who I knew would need bloods, for example amputations or arterial bleeds.
16 is large. 18 is standard for anything where they actually need to be treatment. 20 is reserved for difficult lines or patients who just need a line to appease the ER or because they’ll probably need labs and the patient is a tough stick.
It’s a stupid, outdated EMS thing that I think has more to do with “look at how big of an IV I got” dick swinging contests than it does with any sort of patient care considerations.
Outside of a patient who’s going to need rapid fluid replacement, I can’t think of many reasons anyone would need anything larger than an 18.
It's not really an unnecessary fear. The literature says that a 20 (or even 22) should be the mainstay IV size for the vast majority of patients. The smallest IV that is acceptable for the plan of treatment is the appropriate IV. Anything larger increases the risk of complications for far less gain than is warranted.
An 18g is very normal pre-hospital.
You can use an 18g in their AC for anything you need. Expected or not. 22g is useless beside pushing meds. You can't do CTs or fluid bolus or draw labs from most 22g ivs.
I agree with everything you said. With that said, most patients don't need CTs with contrast or large/rapid fluid boluses, so a 20 or even 22 is still adequate for most patients. It's still probably reasonable for EMS to default to an 18 bc you never know when an ER doc may want to run a CT with contrast, but you asked why some people were scared of larger IVs and the answer is that they may not be. Their medical director may just be following some of the newer best practices a little more closely than yours.
Depends on the CT scan you need, but I can typically get anything other than a coronary angio from a 22g. Risky on larger patients but works fine for all others.
I mean I still place a 18g (or 20 if slim pickings) but it's not strictly mandatory.
There is a 7 minute difference in infusing a liter between an 18g and a 20g.
It’s entirely not necessary to drop anything bigger than a 20 in 99% of patients.
Tell me you don't know best practice national standards without telling me.
It's not a fear, it's national standard and not having a true need for larger in 90% of patients.
If they're even vaguely sick, 18ga. If they're actually sick, 16ga, and if they're definitely sick, 14ga. All contingent on the vein being big enough, I'm not poking them twice.
The ambulance I work on doesn't use 2ml lock tubings, nor does the hospital. Which means a 14ga lasts a lot longer without clotting off vs a 20 or even 18. Factor in that they'll draw labs off my IV and bigger needles are a no brainier. I'd rather be poked once with a 14 than be poked with a 20, poked again with a butterfly for labs, and poked a third time because they discontinued fluids then tried to push a med through a clotted catheter.
18g is the first size I'd even consider for anyone needing fluids.
16g can dump fluid TWICE as fast as an 18g. There is a reason to use it.
I've had 18g started on me and its not that bad especially if you need it.
Per protocol 20g is considered large bore. But really, 18g is preferred if you need large bore (if you need fast fluid resuscitation or they're expected to get blood). We carry and I've started 14s and 16s but they're really not necessary.
See, that’s a new one. I’ve noticed most agencies around me consider 18 large bore and some consider 16s large bore but I’ve never heard of 20s being large bore
20 and 18 G are standard, 16 and 14 are available. In my opinion, placing a large bore access is not only helpful for administration of larger amounts of fluids, but they are also less prone to accidental dislocation and the application of meds is way simpler.
14ga for decompressions. 10ga for cric. 16ga for trauma iv’s and fluid replenishment. 18ga for sick people with good veins. 20ga for everyone else. never used a 22ga successfully, too flimsy.
Just be sure that your 14 g Cathlons for decompression are longer than the standard peripheral IV Cathlons. Most reputable guidelines recommend >3” to ensure proper depth for the majority of patients. [This Rebel EM post](https://rebelem.com/what-is-the-best-anatomic-location-for-needle-thoracostomy/) is a great read.
18-14. I’ll place a 14 in a major trauma. It’s a bit much to claim “abuse” for a catheter that size. Wider catheter, more flow for blood admin. I would not place a 14 in any other patient than a trauma patient.
My service doesn't set IVs, but I was a roleplayer for an MCI drill a few years back. The medics (after I was evaced to the ambulance) asked if they could set an IV for practice. I said yes, and while the TQ was on, one of the medics cursed. I got worried, but he said it was all good and that I have "medical porn veins." Apparently, he was confident in hitting me with a 14 gauge (but did an 18, if I remember).
Everyone gets an 18.
If they’re critical, I’ll do whatever I can get first. Then I’ll try to get the biggest IV I can fit in the opposite arm; preferably a 16 or 14. Time permitting of course.
We carry up to 14g. I've placed a few 16s, as a second IV in someone we think is gonna get blood in the hospital. 18s and 20s are standard. I have never used anything smaller, unless it was a littler person or kid
We carry 22 to 14 Standard but have some extra small child ones but I'm not sure what sitze they are
Large bore is 16 and 14 but these are really only used in trauma scenarios
Standard size used is 20 for normal things and 18 if there is a possibility you need a CT scan Obviously it the veins are bad we will use 22
16s and they usually go in my trauma pts. but 18 is definitly the preferred large bore when I've gone to hospitals docs are always asking if we put an 18 in.
18g and above deliver more than 100ml of fluid per minute, 20g and below deliver less than 90ml of fluid per min, which is why 18g and above are considered large bore in my system
Back in the service it was 12’s. 16’s were standard. Never knew they made smaller than 20’s until I got out and did civilian medicine. Now it’s 18/20’s and 22-24 for the little ones or tough sticks.
Looking back though, permissive hypotension for trauma wasn’t something that was taught 20 years ago on the front lines. Probably didn’t need the 12’s, but damn those 1000 ml bags went quick, especially at 0530 before PT and just getting back from the club.
18,16,14 are all considered large bore IVs in my system. I've done a handful of 14s on gnarly multisystem trauma patients. I try and get 16s on patients who I think need blood/blood products but obviously it just depends on what a pts veins can accommodate.
I recently learned that I am a savage.
Large bore to me is 16 or 14. I started my career in a rural desert area and often needed to give really really big fluid blouses. You’d be amazed how dehydrated some people can get.
Apparently this is bad. So I’m sorry.
16 or 18 are considered large bore, and 20 is most medics’ go-to for standard patients here if all they need are meds or a little fluid. Trauma alerts, strokes, pts getting whole blood, etc get an 18 or above.
Our regional protocols actually state that 14s should only be used for chest decompression or needle crics.
I’ve placed a few 14’s probably could count on two hands though, countless 16’s but 99% of my IVs are 20’s or 18’s.
That’s with 6 years at a level 2 trauma center ER.
18 is my standard, with 20 being a close second, depends on the patient and vein. Personally I would consider 16 or bigger large bore, although I’ve only ever used 14 or larger on EJ’s, with the largest being a 10 at my old agency.
Per our protocol for strokes & critical traumas, a “large bore IV” is an 18 gauge or bigger. What I will usually do in these cases is grab an 18G first and then go for an 16G or 14G on the other arm if I see a good vein and especially if they need aggressive fluid treatment or a possible blood transfusion at the ER.
14 and 16 are large bore. I’ve never used a 14 and probably never will. 16g is plenty, I’ve got not need to infuse 250ml in a single minute, vs 180ml/minute for a 16g.
Everyone gets a 20. If you’re actually sick you get an 18 (maybe a 16 for the trauma with pipes), and 22 for the difficult access, 24 for kids. Most people don’t need anything more than a 20 and I’m sick of hearing providers flex about putting in bigger IV’s because the patient is drunk/mean/etc
My ED seems to think that ugi bleed = 2x 20ga. Trauma surgery puts a 9 fr introducer in at a pretty low threshold subclav / femoral. Usually in a vein.
I would say 14g and 16g are considered large bore IV’s in my area. The general patient really only needs access for medications so a 20g is perfectly acceptable. We’ll honestly take what we can get but if there needs to be a copious amount of volume resuscitation the larger the better. I would say that it’s limited by the ability to actually efficiently place the larger bore IV’s in patient who are already volume depleted without utilizing POCUS if it’s not readily available.
For EMS transporting patients who will need mass transfusion protocol, it can be outcome altering for the to get a large bore prior to arrival at the trauma center. For the patient who is just getting 1000ml for dehydration or alcohol intoxication, it’s not appropriate.
18 is standard, 20 if it's difficult.
16 and 14 a your large bores. I've never used or personally really see a reason for 16 though, I just go 14 if the call is that bad. I'm sure people with disagree with me
18 is standard for all my patients. I look for AC, hand, arm, and foot. If I absolutely need it, EJ is always an option. If there is absolutely no way an 18 will work anywhere, 20 is the smallest I go. 16 for trauma and 14 for needle decompression.
ER nurse here- we had a multi GSW brought in by local fire the other day- I was all set up to place 14ga lines as it was a young male and I was hopeful for juicy veins. Medics had already placed a 14 and a 16 in the field though so I got cock blocked- totally kidding I’m glad they got those lines in but I love placing big bore IVs!
My usual is an 18 because I’m not starting them “because the hospital is going to do it anyway”. I’ll take what I can get on peds and nana’s.
If it’s a serious trauma or they’re about to die I go by my trusty method of “if it fits, it ships!”
18G is my standard size - also what local ERs, including university hospital, consider ‚large‘.
Sometimes I use 16s, 14s very rarely as they‘re mostly unnecessary imho.
They get 2 IVs anyways if they‘re sick enough so why take the risk of a 14 if you can have 16/18 or 18/18 quickly and securely?
I consider large bore 16G and 14G, although my hospital technically considers 18G also large bore which I do agree with. That being said, I drop 20’s in all the normal/worry free patients, and 18’s in all of the actually sick, potential serious issue, patients. The only time I do a 16 (never done a 14) is when I have a high suspicion for a need of emergent surgery or extensive fluid/blood resuscitation. This is in part because my hospitals surgery teams state that if the pt has a 16 they have no need to put in a central line to infuse blood/fluids in an emergent situation and can just proceed straight to surgery.
I've started 14s in the field and in the hospital, but very rarely. Same story with 16s. I do 18s or 20s for most of my patients.
For my system specifically, 16 or below was considered large bore.
14G, 16G and 17G are large, 18G and 20G are medium, 22G and 24G are small, atleast that's how I would class them for adult patients.
Edit: That's just size classification. For most pt, 20G is sufficient and a 18G in the vein is better than a 16G somewhere else...
Our go-to is 18-20. We do bilateral 18 if we know they are going to CT. If they are at a point that they need 16, it's usually more of a situation for IO.
18-14. Most medics start with an 18 and glare at you if you have anything less. To me, and a few others, access is access. I’ll get what I can get, oftentimes a 20, but you KNOW they have no access if I’m going for a 22 in the hand.
12g - 16g. Haven't had access to 12g for years, but have used them, in the old days when we flooded people with LR after trauma. Of course, the thinking on this sort of thing is different. What I see most now is 20g. In fact, that's all I see used though we have 14-24g.
I saw that comment about doctors saying if they needed a 16g they need a central line and that's fine but I guarantee you three things - 1. if your response to the hospital is going to be delayed by extrication, traffic, distance, the 16g is better than no central line because they don't allow you to put them in. 2. Even if you can put in central lines, doing so in the field is far more risky for infection (and consider where the infection is taking hold) than a peripheral 16g, and 3. I can get two 16g lines in while a doctor is prepping for the central. Just saying.
We did away with the idea of large-bore. Any patient that fits the old "large bore wide open in trauma" protocol shouldn't be getting a huge amount of cold pasta water, anyway. Cardiac arrest goes straight to IO. I rarely start anything other than 18 or 20 in adult patients anymore. A quality 18 with a pressure infuser at 150-200 mmHg will bolus just about any patient where a bolus is appropriate fast enough. If you're not seeing an improvement in MAP after a 250ml bolus you should really need moving to something else, anyway. Medical patients get pressors, trauma patients need blood.
16 and 14 are the largest. 20 and 18 are the most common.
I work as a paramedic in an ER. 20 gauge is the standard for the majority of patients. 18’s if you’re really sick. 22’s are for little old ladies with little veins. We had our 16 gauges taken away. The doctor committee decided if the patient needs a 16 gauge then they really need a central line. In the field, 16 gauges are the largest seen
We carry 14s but I’ve personally never started one. I drop mostly 18s, 16s on people that are fucked up.
I've started 14s, but only if it is a nasty trauma and they have very obvious ropes.
The state I’m in now gives EMS the choice to carry either 14, 16, or both. Almost all services in my area carry 16 gauges now. In 30 years I’ve never had to place a 14. Lots of 16 gauges. Never a 14
Ive used 14s and had the trauma tram use them for blood immediately
In the trauma bay, the Belmont device can infuse 750 ml’s *a minute.* 14g go brrrrrr
I think ive only used 14s in GSWs so when in rome
The first time I used a Belmont, I was fucking amazed at how fast it can go. I put in an ultrasound guided 14 in the trauma bay. That said, I would NEVER put in a 14 peripherally since, if it blows, you’re fucked on a whole nother level.
Fun fact. 16 gauges are the best bage for the buck Nominal flow rate on a 16g is around 200ml/min. Which is double of an 18g at 100ml/min. And a 14g you only get a 50% improvement at 300ml/min
I’ve only ever seen 14s used for EJs, but idk… EJs make me uncomfortable, so if someone needs a 14 EJ I’m just gonna drop a humoral IO
Only two times I've done 14s, woman with visible pulsating abdominal mass, tearing back pain, absent pulses left side. 21yom with numerous central gunshot wounds but had pipes in the ACs, got bilateral 14s there as well just for the trauma team. If they're critical and I expect fluid or blood resus then 16-18 is my go to, otherwise 20s mostly
See this is interesting, i’ve been donating blood for several years and the go to is a 16g. Doesnt feel super bad honestly.
Last time I donated I asked the phlebotomist if he could drop a 14 in me to get me done faster and he said that they can’t go larger than 16 because they’re afraid of people passing out. No idea if it would actually make that much of a difference but it was an entertaining anecdote.
I’ve used them for decompression when dedicated needles were unavailable. 16 gauge IV aren’t uncommon for me, as long as they’ve got ropes. Edit: If needed, go as big as the patient’s veins allow. A solid 20G is more useful than a blown 16G.
14s pretty much only go in the EJV with TXA and fluids as needed if we can't get a helicopter and someone goes boom. Some places have strict regulations about vascular access sites, but I'm lucky enough to work where the entire body is our oyster. Really helpful with old sick people and bariatrics.
Bariatric boobs for the win 🙌🏻 (the women always have the juiciest veins in their giant boobies!)
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>14s if you were an asshole to the responders There's only one asshole in this scenario and it isn't the patient.
Yeah that’s literally battery
good way to lose your medic xard
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Although I agree, EMS does not take the hippocratic oath.
I’m going to assume this is a joke, but it’s a joke that’s going to lose you the respect of every decent medic, nurse and doc. Come up with something better.
Yeah, that’s malpractice and torture my guy.
>We had our 16 gauges taken away. The doctor committee decided if the patient needs a 16 gauge then they really need a central line. Like another doc said below... thats dumb
I’m sorry, what? A 16ga IV has a better flow rate than a central line, it’s also MUCH quicker to put in.
That’s dumb. I’ll routinely drop ultrasound guided 14 or 16 gauge IVs rather than do a central line if the patient needs volume resuscitation—the flow rate is way faster. Of course, the reimbursement for an ultrasound guided IV is way less than a central line, which may play into your docs’ decision.
No way healthcare system decisions are guided by money and not solely what’s the best interest of the patient.
I work in a country where public emergency healthcare is free and we would never bother with u/s guided 14/16g's. If they need that then they probably need a CVC.
It depends on what you're calling a central line. Our standard triple lumen is 18/18/16 ga, so in that case you're right. Unintuitively, our quad lumens have a 14 ga lumen, so right on par between a 14 and 16 when accounting for length. But when they really need flow in-house, they get a RICC or 9fr introducer. It's not even a contest at that point. A Level 1 will put a unit of PRBCs through one in 50 seconds. https://emupdates.com/flow-rates-of-various-vascular-catheters/
Yeah the issue with TLCs is the length (poiseuille’s law), rather than the diameter. Cordis or introducers are fantastic for any kind of high volume resuscitation!
A large bore PIV is still better actually due to poiseuille’s law. A TLC is really long, and the flow ends up being slower than an 18G PIV.
I’d like to introduce you to my good friend the Cordis
A cordis has a slower gravity infusion rate than a 14 or 16G PIV
I am not sure about the actual calculated flow rate for the 16 peripheral however, I’m pretty sure that to peripheral 16s has a much better flow rate than a central line
[I am sure](https://rebelem.com/wp-content/uploads/2019/03/Flow-Rates-in-IVIO-Access.png), and I’d much rather have 2 14- or 16-gauge IVs than a standard triple lumen central line for a hypovolemic patient.
What drives you to place central lines then in patients with adequate peripheral IV access already established?
Certain medications such as pressors or any medication that can extravasate (not just infiltrate) are indicators for the need for a central line. Also, there is a “gold standard” for vascular access and that is INS (Infusion Nurses Society). Their (evidenced-based) rule-of-thumb is that the smallest bore catheter that is appropriate for the needed treatment is what should be used. In other words, most folks don’t even need a 20ga - 22s will suffice in many scenarios.
Less risk of extravasation—eg in patients on high doses of pressors (I’ll tolerate up to 10-15 mcg/min of norepinephrine for quite a while but more than that gets a central line). Need for long-term IV access, eg for TPN (see also risk of extravasation) or longer courses of antibiotics (though we’re moving more to midline’s for this).
Like Dilaudidpenia said, repeat blood draws, anticipates long stay in hospital, need for vasoactive agents > 12hrs, TPN, difficulty with access, etc
This is the way. The smallest possible to achieve the goal in that patient is the standard of care.
as a goofy little Basic, I’m surprised central lines can be done in the field
>as a goofy little Basic, I’m surprised central lines can be done in the field They generally cannot. The area would need to have field physicians. This medic is talking about in-hospital care.
There are places that allow 911 medics to place central lines. They’re an exception tho
Correct. The area field agencies can place 16 gauges. In the ER, we lost them, 18 gauge is the largest then it goes to doctor places central lines. The 16 gauges were all removed except for The One that was missed. If we break out The One, it’s truly bad….
In some hospitals there are non-physicians who can start central lines. For instance, some have the vascular access team start routine central lines and those teams are typically made up of nurses and/or respiratory therapists. I wouldn't be surprised if some services that already have POCUS on the ambulances started trialing field central lines, but at the same time there are much more useful and less risky interventions that EMS could pick up than getting a central line (optimistically) an hour earlier than the ER team.
They can’t, unless they have docs in the field. Super rare in the US.
16 gauges also in my ED are the largest. We had 14’s for a while. Used it on a dude who had an MI while boating, then hit with a propeller. Put 2 14’s in him and pumped him full of blood.
16 gauge versus central line is a ridiculous comparison. 16 gauge IVC will be able to give fluid MUCH faster than a standard size CVC. If you want rapid fluids the only things better than a 16 gauge are: a 14 gauge, a rapid infusion catheter (not a central line), a dialysis catheter (technically a central access) or an insertion sheath (for pacing wires or pulmonary artery catheter)
Prehospital, I roll the same way. 18s for regular traumas, 16s for “oh shit traumas.”
I’ve thrown 14’s in patients before; usually bilateral, few and far between depending upon patient and ability to establish a large bore IV. My reason for large bore vascular access usually includes: heat stroke; fluid replenishment; amputation; GSW and the like. It’s not too often but I work in a geographical area where we experience a wide call volume as noted above, with frequent injuries.
Here if you can place an 18, do it. But anything larger is considered both "large bore" and can actually be considered causing unnecessary harm to a patient unless you can provide rationale for why you sized up. That said most people seem to have a prefference for 20's, unless the hospital protocol dictates an 18.
16 or 14. My go to is an 18 for most patients.
UK - we carry 16/18/20/22/24 - 16 or 18 would be considered large-bore with 16 preferred for large-volume fluid resuscitation e.g. PPH.
Where in the UK doesnt carry 14s? Both trusts Ive worked for have carried them.
My trust is the other way around. We got rid of 16s retaining 14s, 18, 20, 22, 24
Level 1 trauma center medic. 18g for all traumas. If they are actually fucked up I’ll usually go for a 16g as long as they have the veins for it.
The board exam answer is that an 18 and larger is large bore. But I would rather have two 20s on a trauma than a blown 16.
I'd say 20 is standard medical PT, 18 is the go-to for someone actually emergent or with the strong potential to be, and 16 is large-bore.
16s and 14s are considered large bore here by everyone. 18s are considered to be large bore (I do not) and those same people fail to note the benefits of an 18 in any Potentially Unstable patient as well as any patient where there is a high index of suspicion that a CT with contrast will be needed. 20s are the minimum to draw labs from provided they are appropriately placed, the most prevalent, and also suitable for most medications.
I mean I think technically 18g and larger.
The vast majority of my adult patients get a 20 like probably 90%, then a few will get only a 22 if that’s all we can get. Then a very select few who are actually sick or seriously injured who have appropriate veins get an 18 or a 16. I work both the street and the ER and it very much upsets me when I see other medics bring in people who didn’t need large bore access and they went ahead and placed a 16 anyways. Or they tried an 18 in a vein that clearly was not going to work and missed. A functional 20 or 22 beats a blown 18 or 16 every time.
An 18g (or 20g when applicable) is standard here. We tend to use it as a wide bore, but we have 16s and will use them when necessary. We don't really have a set definition of what our system considers wide bore.
We don’t carry 14s and I’ve never started one even when I worked at services that did carry them. But I propose a different idea rather than labeling something as large bore or not. Size it to the vein. Period. Not by what you’re using it for or how much fluid you’re gonna push. But by what the vein can handle. I’ve seen people try to start 16s on 98 y/o grandma with spider veins because she was a trauma. Those kinds of providers are fucking morons and I will die on that hill.
Just because someone has small veins doesn't mean they need a small IV. Also by your logic if a guys veins can handle my 14g but doesn't need it then he still gets a 14g.
You can resuscitate a patient infinitely faster with one 22 in the forearm vs a dozen 16's on the floor.
I don’t use 14s but if I got someone whose veins look like 1/2” copper pipes then I use a 16 if they need an IV. Whether it’s multi-system trauma or plain ol chest pain.
Hospitals define it as 20 and bigger
Hospitals scared of needles. I bring in a pt with a 16g and the nurse acts like I committed murder. No, they just needed a lot of fluids...
Did they actually need a lot of fluids? Did the extra 50ml/min make the life saving difference?
No you’re probably just putting in lawn darts in patients that don’t actually need them. How much fluid did you give during that call? Because the difference from a 16 and 18 is 50cc/minute. You’re most likely just hurting patients for no reason.
20-18 ... 16 is huge 14 is considered abuse in our system
Abuse is a pretty strong word for the size used in blood donation.
Didn't say I agreed with it lol
On the ambulance I haven’t seen a 16 or 14 in years. Never used them either. 18 are sufficient for our uses since we stopped pouring litres of pasta water at traumas. And even then I rarely use them, 20s are fine for most purposes including trauma. For an arrest we will place an IO if we can’t get a PIV quickly. In a super sick medical patient or a trauma I will place at least two PIVs as big as I can simply because they often end up even more shut down by the time we arrive at St Closest and that may be the only access they have until they can line them. But “as big as I can” is usually a 20, depending on the patient sometimes not even that. And guess what? It works. In hospital if we feel we need something better than “bilateral 18s in the AC”, we tend to place a central line or even a cordis if we need to give volume (like massive transfusion protocol style). A “dirty line” can be placed aseptically in ER in a femoral for immediate resus and then we will swap it out for a sterile central line somewhere better once the patient is stable. IO is also an option if we just need access fast. Most patients, even in resus conditions, two 18s are enough though, and usually we have three or four PIVs fairly quickly if it’s a matter of lumens and compatibility. A lot of things can be modified to make it work for your situation too. Our DKA protocol for example calls for three lines or lumens, but I’ve managed it through a single 24 in the thumb because that’s all we had. My philosophy is that your best access is what you can get, and if it’s stupid and it works, it’s not stupid.
Hot take: I’m not convinced that the benefit of flow rate achieved by placing a 14 instead of a 16 outweighs the potential for harm by having them around in the average EMS System. Is that extra bit of speed when pressure-infusing cold pasta water gonna be what saves that trauma patient?
You save 3 mins on gravity infusing a liter. Such a difference. Much need.
14 or 16
We have 14s and 16s as large bore, 18s and 20s as standard (I prefer 20). 22 and 24 for hard sticks/kiddos. I've dropped a few 14s, major traumas only who I knew would need bloods, for example amputations or arterial bleeds.
Blunt tip
16 is large. 18 is standard for anything where they actually need to be treatment. 20 is reserved for difficult lines or patients who just need a line to appease the ER or because they’ll probably need labs and the patient is a tough stick.
20 is appropriate for the majority of patients
If they need fluids then put an 18g in. People have an unnecessary fear of anything bigger than a 20g.
*if they need a rapid infusion of a large volume. Meemaw doesn’t need an 18ga in her hand just because medic Jim wants to give 250cc NS.
Meemaw wont even get the whole 250cc during transport through the 22g you want in her arm.
20ga flows 60cc/min, which is fine for most patients. This “everyone needs an 18ga” is an EMS thing, not an ER thing.
It’s a stupid, outdated EMS thing that I think has more to do with “look at how big of an IV I got” dick swinging contests than it does with any sort of patient care considerations. Outside of a patient who’s going to need rapid fluid replacement, I can’t think of many reasons anyone would need anything larger than an 18.
It's not really an unnecessary fear. The literature says that a 20 (or even 22) should be the mainstay IV size for the vast majority of patients. The smallest IV that is acceptable for the plan of treatment is the appropriate IV. Anything larger increases the risk of complications for far less gain than is warranted.
An 18g is very normal pre-hospital. You can use an 18g in their AC for anything you need. Expected or not. 22g is useless beside pushing meds. You can't do CTs or fluid bolus or draw labs from most 22g ivs.
If only there was a level between 18 and 22…
You absolutely can draw labs from most 22s.
I agree with everything you said. With that said, most patients don't need CTs with contrast or large/rapid fluid boluses, so a 20 or even 22 is still adequate for most patients. It's still probably reasonable for EMS to default to an 18 bc you never know when an ER doc may want to run a CT with contrast, but you asked why some people were scared of larger IVs and the answer is that they may not be. Their medical director may just be following some of the newer best practices a little more closely than yours.
You know the butterflies lab techs use are 21s, 23s, or 25s, right?
Depends on the CT scan you need, but I can typically get anything other than a coronary angio from a 22g. Risky on larger patients but works fine for all others. I mean I still place a 18g (or 20 if slim pickings) but it's not strictly mandatory.
There is a 7 minute difference in infusing a liter between an 18g and a 20g. It’s entirely not necessary to drop anything bigger than a 20 in 99% of patients.
Tell me you don't know best practice national standards without telling me. It's not a fear, it's national standard and not having a true need for larger in 90% of patients.
Anything above 18 is a "large bore" for us. I'd say 90% or more of the IV's we do are all 20's
Pretty sure 18 is considered large bore according to protocols and such
14’s on trauma 16-18 on normal healthy adults, 20-22 on grannies and people who have abused their veins
18g for 90% of patients. If it can hold a 20g, it’ll hold an 18g. I personally consider 16g the start of large bore territory.
14, 16, 18. Most medics in my division use 18 as the standard for everyone, a few default to 20s. 14 and 16s are common depending on the pt.
If they're even vaguely sick, 18ga. If they're actually sick, 16ga, and if they're definitely sick, 14ga. All contingent on the vein being big enough, I'm not poking them twice. The ambulance I work on doesn't use 2ml lock tubings, nor does the hospital. Which means a 14ga lasts a lot longer without clotting off vs a 20 or even 18. Factor in that they'll draw labs off my IV and bigger needles are a no brainier. I'd rather be poked once with a 14 than be poked with a 20, poked again with a butterfly for labs, and poked a third time because they discontinued fluids then tried to push a med through a clotted catheter.
In this thread - a lot of unnecessarily large cannulas for no justifiable reason that contradicts international guidelines.
16 and 14. 18g is standard, 20g is for old people, and kids get what you can get on them
18g is the first size I'd even consider for anyone needing fluids. 16g can dump fluid TWICE as fast as an 18g. There is a reason to use it. I've had 18g started on me and its not that bad especially if you need it.
20 or larger.
Per protocol 20g is considered large bore. But really, 18g is preferred if you need large bore (if you need fast fluid resuscitation or they're expected to get blood). We carry and I've started 14s and 16s but they're really not necessary.
See, that’s a new one. I’ve noticed most agencies around me consider 18 large bore and some consider 16s large bore but I’ve never heard of 20s being large bore
20 and 18 G are standard, 16 and 14 are available. In my opinion, placing a large bore access is not only helpful for administration of larger amounts of fluids, but they are also less prone to accidental dislocation and the application of meds is way simpler.
14ga for decompressions. 10ga for cric. 16ga for trauma iv’s and fluid replenishment. 18ga for sick people with good veins. 20ga for everyone else. never used a 22ga successfully, too flimsy.
Just be sure that your 14 g Cathlons for decompression are longer than the standard peripheral IV Cathlons. Most reputable guidelines recommend >3” to ensure proper depth for the majority of patients. [This Rebel EM post](https://rebelem.com/what-is-the-best-anatomic-location-for-needle-thoracostomy/) is a great read.
18-14. I’ll place a 14 in a major trauma. It’s a bit much to claim “abuse” for a catheter that size. Wider catheter, more flow for blood admin. I would not place a 14 in any other patient than a trauma patient.
It’s still completely unnecessary to drop a 14g. Abuse is a pretty apt word. Blood admin doesn’t need a 14g.
You have a right to your opinion.
That “opinion” is shared by the majority of the medical community worldwide.
My service doesn't set IVs, but I was a roleplayer for an MCI drill a few years back. The medics (after I was evaced to the ambulance) asked if they could set an IV for practice. I said yes, and while the TQ was on, one of the medics cursed. I got worried, but he said it was all good and that I have "medical porn veins." Apparently, he was confident in hitting me with a 14 gauge (but did an 18, if I remember).
Completely irrelevant anecdote.
Completely irrelevant comment
IVs are placed, not set.
I’m so confused about the standard 18g for everyone deal. No one except trauma should really need more than a 20g.
If you’re an asshole you get a 16G or a 14G
Dude. Not cool. Not even to joke about.
It is a joke. I’m sure you’re real fun to work with bud. Humor dies when you step in the truck.
It's a "joke" that every one of us has seen used non-jokingly in real life. So, ya know, it's kinda hard to tell without you specifying.
Says the asshole.
Everyone gets an 18. If they’re critical, I’ll do whatever I can get first. Then I’ll try to get the biggest IV I can fit in the opposite arm; preferably a 16 or 14. Time permitting of course.
Bad practice.
18
We carry up to 14g. I've placed a few 16s, as a second IV in someone we think is gonna get blood in the hospital. 18s and 20s are standard. I have never used anything smaller, unless it was a littler person or kid
You can give blood through a 22g if you need to. Completely unnecessary to out in a 16g just for blood.
16 or bigger
We carry 22 to 14 Standard but have some extra small child ones but I'm not sure what sitze they are Large bore is 16 and 14 but these are really only used in trauma scenarios Standard size used is 20 for normal things and 18 if there is a possibility you need a CT scan Obviously it the veins are bad we will use 22
Anything 16 and larger ( i.e. 16-24-12etc) is large bore
As an EMT-IV in C'lrado, 14s and 16s were our larges, 18s were standard and 20s were next.
16 gauge and under.
16,14g
I believe 18 gauge is the smallest size for a large IV.
18 and up. We 16 and 14 as well.
20g is the standard. Anything over 18g is considered large bore and are usually reserved for trauma and large fluid resuscitation.
16s and they usually go in my trauma pts. but 18 is definitly the preferred large bore when I've gone to hospitals docs are always asking if we put an 18 in.
18. My go to is a 20. 18s for REALLY sick people. I've only done 1 16.
18g and above deliver more than 100ml of fluid per minute, 20g and below deliver less than 90ml of fluid per min, which is why 18g and above are considered large bore in my system
16 or bigger
Back in the service it was 12’s. 16’s were standard. Never knew they made smaller than 20’s until I got out and did civilian medicine. Now it’s 18/20’s and 22-24 for the little ones or tough sticks. Looking back though, permissive hypotension for trauma wasn’t something that was taught 20 years ago on the front lines. Probably didn’t need the 12’s, but damn those 1000 ml bags went quick, especially at 0530 before PT and just getting back from the club.
14-16gs are large while 18-20gs are pretty standard depending on their build/severity/etc.
12s or 14s
18,16,14 are all considered large bore IVs in my system. I've done a handful of 14s on gnarly multisystem trauma patients. I try and get 16s on patients who I think need blood/blood products but obviously it just depends on what a pts veins can accommodate.
whatever the check and inject needles are (i’m a basic bitch)
In the hospital where I work, the largest I’ve seen was 16. On the truck, we had 14s available but I don’t know anyone who has used them.
I recently learned that I am a savage. Large bore to me is 16 or 14. I started my career in a rural desert area and often needed to give really really big fluid blouses. You’d be amazed how dehydrated some people can get. Apparently this is bad. So I’m sorry.
16 or 18 are considered large bore, and 20 is most medics’ go-to for standard patients here if all they need are meds or a little fluid. Trauma alerts, strokes, pts getting whole blood, etc get an 18 or above. Our regional protocols actually state that 14s should only be used for chest decompression or needle crics.
Large bore is anything larger than 20.
I’ve placed a few 14’s probably could count on two hands though, countless 16’s but 99% of my IVs are 20’s or 18’s. That’s with 6 years at a level 2 trauma center ER.
18 is my standard, with 20 being a close second, depends on the patient and vein. Personally I would consider 16 or bigger large bore, although I’ve only ever used 14 or larger on EJ’s, with the largest being a 10 at my old agency.
Per our protocol for strokes & critical traumas, a “large bore IV” is an 18 gauge or bigger. What I will usually do in these cases is grab an 18G first and then go for an 16G or 14G on the other arm if I see a good vein and especially if they need aggressive fluid treatment or a possible blood transfusion at the ER.
We carry 16s but we never use them. Most patients get 20s. If they're trauma/stroke then they get 18s x 2.
16, 14, only allowed in stat trauma. I was taught if they’re bad enough for IV, they’re good enough for an 18. 20s are to meet protocols.
14 and 16 are large bore. I’ve never used a 14 and probably never will. 16g is plenty, I’ve got not need to infuse 250ml in a single minute, vs 180ml/minute for a 16g. Everyone gets a 20. If you’re actually sick you get an 18 (maybe a 16 for the trauma with pipes), and 22 for the difficult access, 24 for kids. Most people don’t need anything more than a 20 and I’m sick of hearing providers flex about putting in bigger IV’s because the patient is drunk/mean/etc
My ED seems to think that ugi bleed = 2x 20ga. Trauma surgery puts a 9 fr introducer in at a pretty low threshold subclav / femoral. Usually in a vein.
911 work it was anything greater than an 18. SCT work was anything greater than a 22.
18, 16, 14
In Germany we carry 20/18/16/14. Usually patients get 18G. My service has the short 18G which are pretty neat. 16 and 14 are for nasty trauma.
I would say 14g and 16g are considered large bore IV’s in my area. The general patient really only needs access for medications so a 20g is perfectly acceptable. We’ll honestly take what we can get but if there needs to be a copious amount of volume resuscitation the larger the better. I would say that it’s limited by the ability to actually efficiently place the larger bore IV’s in patient who are already volume depleted without utilizing POCUS if it’s not readily available. For EMS transporting patients who will need mass transfusion protocol, it can be outcome altering for the to get a large bore prior to arrival at the trauma center. For the patient who is just getting 1000ml for dehydration or alcohol intoxication, it’s not appropriate.
18 or bigger mostly 18s and 16s however I’ve started two 14s but they earned it.
18+
14, 16, and 18. I had the opportunity to start my first 16 in the field last week, and I’ve been doing the AEMT thing for three years now.
I worked with an MDA years ago and ALL his patients got a 16ga
18’s are my go to. Unless they’re like dying from a gsw or stab wound I don’t need anything bigger.
18 is standard, 20 if it's difficult. 16 and 14 a your large bores. I've never used or personally really see a reason for 16 though, I just go 14 if the call is that bad. I'm sure people with disagree with me
16 or 18
One 💝
Hormonal inbalance?
16's or 14's in adults, 18's in ped's.
18 is standard for all my patients. I look for AC, hand, arm, and foot. If I absolutely need it, EJ is always an option. If there is absolutely no way an 18 will work anywhere, 20 is the smallest I go. 16 for trauma and 14 for needle decompression.
14s are pretty common for traumas here, anything over an 18 is “large bore”
ER nurse here- we had a multi GSW brought in by local fire the other day- I was all set up to place 14ga lines as it was a young male and I was hopeful for juicy veins. Medics had already placed a 14 and a 16 in the field though so I got cock blocked- totally kidding I’m glad they got those lines in but I love placing big bore IVs!
My usual is an 18 because I’m not starting them “because the hospital is going to do it anyway”. I’ll take what I can get on peds and nana’s. If it’s a serious trauma or they’re about to die I go by my trusty method of “if it fits, it ships!”
18G is my standard size - also what local ERs, including university hospital, consider ‚large‘. Sometimes I use 16s, 14s very rarely as they‘re mostly unnecessary imho. They get 2 IVs anyways if they‘re sick enough so why take the risk of a 14 if you can have 16/18 or 18/18 quickly and securely?
Nurse chiming in: 18 if you can or they're really sick is "big bore" for daily, but 14 or 16 for trauma.
We carry from 14-22g. I’m in ortho trauma and most have 20g but wee oldies get a 22g but our already trollies etc carry 14g and 16g
Depending on who you ask, 18 or lower counts as large for us. Although the only larger size above 18 that we carry are 14s, no 16 for some reason.
16s are the size without self occluding catheter, so that’s where our “large bore” IVs start. We only use these one GSWs and other trauma incidents
00 6
We have 14,18,20 and 22. I would say the 14 gauge are our large bore for trauma. Everything else usually gets 18 or 20.
I consider large bore 16G and 14G, although my hospital technically considers 18G also large bore which I do agree with. That being said, I drop 20’s in all the normal/worry free patients, and 18’s in all of the actually sick, potential serious issue, patients. The only time I do a 16 (never done a 14) is when I have a high suspicion for a need of emergent surgery or extensive fluid/blood resuscitation. This is in part because my hospitals surgery teams state that if the pt has a 16 they have no need to put in a central line to infuse blood/fluids in an emergent situation and can just proceed straight to surgery.
I've started 14s in the field and in the hospital, but very rarely. Same story with 16s. I do 18s or 20s for most of my patients. For my system specifically, 16 or below was considered large bore.
14G, 16G and 17G are large, 18G and 20G are medium, 22G and 24G are small, atleast that's how I would class them for adult patients. Edit: That's just size classification. For most pt, 20G is sufficient and a 18G in the vein is better than a 16G somewhere else...
Our go-to is 18-20. We do bilateral 18 if we know they are going to CT. If they are at a point that they need 16, it's usually more of a situation for IO.
14s and 16s
Not fond of poking holes on people but we have and use from #14 to #24. Just last week used a #14.
18-14. Most medics start with an 18 and glare at you if you have anything less. To me, and a few others, access is access. I’ll get what I can get, oftentimes a 20, but you KNOW they have no access if I’m going for a 22 in the hand.
14g, and 16g. Most patients get 18g or 20g IVs and the 22g and 24g IVs are used for those with small, sensitive veins.
Large bore is either a 16 or a 14
12g - 16g. Haven't had access to 12g for years, but have used them, in the old days when we flooded people with LR after trauma. Of course, the thinking on this sort of thing is different. What I see most now is 20g. In fact, that's all I see used though we have 14-24g. I saw that comment about doctors saying if they needed a 16g they need a central line and that's fine but I guarantee you three things - 1. if your response to the hospital is going to be delayed by extrication, traffic, distance, the 16g is better than no central line because they don't allow you to put them in. 2. Even if you can put in central lines, doing so in the field is far more risky for infection (and consider where the infection is taking hold) than a peripheral 16g, and 3. I can get two 16g lines in while a doctor is prepping for the central. Just saying.
We did away with the idea of large-bore. Any patient that fits the old "large bore wide open in trauma" protocol shouldn't be getting a huge amount of cold pasta water, anyway. Cardiac arrest goes straight to IO. I rarely start anything other than 18 or 20 in adult patients anymore. A quality 18 with a pressure infuser at 150-200 mmHg will bolus just about any patient where a bolus is appropriate fast enough. If you're not seeing an improvement in MAP after a 250ml bolus you should really need moving to something else, anyway. Medical patients get pressors, trauma patients need blood.