Musings of a Dinosaur

A Family Doctor in solo private practice; I may be going the way of the dinosaur, but I'm not dead yet.

Wednesday, September 27, 2006

Bevel Down

(Edited: Marble Dinosaur Egg #3; whoever said dinosaurs could count?)

I've noticed that several of my readers are medical or nursing students still learning basic clinical skills. I'd like to share something that, once I got around to trying it, has stood me in very good stead indeed.

More years ago than I care to disclose, when I was a 4th year student on an "outside" rotation, I met a crusty old FP with a tic disorder we never spoke of, and a zillion little clinical pearls he was eager to share.

Here's one: when drawing blood or starting an IV, go in with the needle's bevel down.

Yeah. Right. What does an old guy like him know about drawing blood anyway, I thought. Just like all of you, I was taught that the bevel (the hole in the needle cut at an angle) should be up so you can see it as you go through the skin and into the vein.

Fast forward to the present: I cannot for the life of me remember when or why I decided to try it (I know it took many years) but I seem to recall a diagram like this one changing my mind:
(This is just a crappy hand-drawn sketch, but the needles are outlines of the same cardboard template flipped over, lined up as parallel as possible.)

As you can see, entering the vein (at any angle) with the bevel down instead of up vastly increases the area of the bevel that gets into the lumen. It's also much easier to avoid damaging the back wall of the vein with the tip of the needle, especially if you concentrate on exerting upward pressure once you've entered the vein.

Nowadays I draw all my own bloods -- bevel down -- and have developed an amazing reputation among my patients for hitting veins no one else can. (The other tricks are not even to start looking until after the tourniquet is on, and going by touch. Always go for one you can feel even if you can't see it, instead of one you can see but not feel. You'll miss the latter every time. If I can't feel it I won't even try.) Granted my near 100% success rate at this point may be just from sheer experience, but almost every patient who's ever had blood drawn by another phlebotomist says my sticks hurt less. Some even claim they don't feel it at all, a phenomenon I have actually experienced drawing my own blood. (Don't ask.)

I know it goes against everything you've been taught, but consider trying it sometime; maybe when you're not being watched/graded. Or you can do as I did and wait an extra decade or so to fine tune your skill. You have nothing to lose but a hematoma.

18 Comments:

At Wed Sep 27, 12:41:00 AM, Blogger yublocka said...

Hi there, been reading your blog for a while but this is my first comment. And yes like many of your readers I am a med student.

That explanation is really interesting. We have definately been taught bevel up not down, although that diagram does make great sense.

So far I've only done venepuncture on a real person once so I have nothing to compare by, but next time I am at hospital I will def ask our educator on her views on the bevel up/down as I am sure she will have an opinion either way.

Anyway thanks for sharing, look forward to more pearls in the future!

 
At Wed Sep 27, 01:23:00 AM, Blogger Dreaming again said...

I hate it when I tell people that I'm a hard stick. They look and SEE and say Nah! You'll be easy.

No, I'm not, really, I get monthly lab draws ...for almost 13 years. Trust me. I'm not an easy stick. I don't care what you SEE when you look.

Then they start to feel "oh, here's a good one!"

Please make sure that's not the scar tissued area.

"nah! this is a good vein! Whoever told you you were a hard stick didn't know what they were doing!"

Stick (as the JAB feels like I've just been jabbed with needle the size of the Seattle space needle)

Hmmmm ... it collapsed. No blood is coming. Odd, funny, you looked like you were an easy stick.

"yea, gee ...funny. Told you I was a hard stick.

Glare.

 
At Wed Sep 27, 05:26:00 AM, Blogger Flea said...

I don't think I'm brave enough to change my technique at this point. Bevel up, for me, is like sneezing with my eyes closed: Not sure I could do it another way.

best,

Flea

 
At Wed Sep 27, 08:24:00 AM, Anonymous ripple of hope said...

Hmmmmm, I'd prefer to just avoid the needles . . . My advice is to have some stupid comics posted for patients to look at while you sticking them so they can focus their attention elsewhere. ;o)

 
At Wed Sep 27, 10:31:00 AM, Blogger MedStudentGod said...

I will have to try this when I'm able to - since I'm usually being observed while performing this procedure. I had been told that you do bevel up to avoid blood being leaked out, but it seems if you do it quickly then you shouldn't have that problem anyway.

Interesting posts of late, I've been so busy I had missed several in a row. Keep up the discussions, I'm quite enjoying them.

 
At Wed Sep 27, 05:09:00 PM, Blogger #1 Dinosaur said...

Flea: It took a lot of courage the first time I did it too. Old habits and all; getting used to new things, yadda yadda. All I can say is this produced a truly fantastic payoff in terms of reduced pain/hematoma incidence. Consider re-considering.

 
At Wed Sep 27, 11:33:00 PM, Anonymous Pine Baroness said...

Thank you for the tip. It is one of those tidbits to file away in the back of one's mind in case it is needed. I am a non-medical person (I'm an engineer) but my child is medically fragile. He was once stuck 14 times in the ER - they never were able to get the IV in. I said enough, do without it so I took my dehydrated child home.

 
At Thu Sep 28, 12:41:00 AM, Blogger Dreaming again said...

I had, in all my blood letting *wink* never been stuck by a doctor. Nor, had I heard of a patient being stuck by a patient except in the med school clinics.

So, I read this ...make my smart elic comment about scar tissue.

My husband goes to a new doctor today, pulmonologist ... who ...draws my husbands blood and blood gasses HIMSELF!

Alrighty then.
Had I known that the doctor was going to do this, I would have told Don to watch for the angle of the needle!!!

 
At Thu Sep 28, 06:20:00 AM, Blogger #1 Dinosaur said...

Dreaming: Actually I'm just talking about venous blood draws. ABG's (sticking an artery) are done completely differently: different kind of syringe, probably a very short bevel whose angle wouldn't matter much. Then again, I have to confess to a good many years since my last arterial stick. If someone's sick enough to need ABG's, they shouldn't be in my office.

Pine Baroness: Thanks for the compliment, but as you probably know, the next time you're in the ER with your kid, even if you do share this with them no one will listen to you; everyone's all caught up in a cross between "the way we've always done it" and "I can't change now."

Then again, as long as your kid's not having both vomiting and diarrhea at the same time, oral rehydration should be just fine. (I was about to go ahead and tell you what I tell my patients, but I thought, hey, that'd make a good post. So stay tuned.) {shameless plug}

 
At Thu Sep 28, 09:01:00 AM, Blogger Blog, MD said...

Fascinating. I will try this. Of note, it looks like this has been studied before.

 
At Thu Sep 28, 03:54:00 PM, Blogger #1 Dinosaur said...

Thanks for the reference, Dr. Blog. I looked it over, and although the bevel down technique wasn't shown to be superior in the specific context of pediatric ER IV starts, I still think it has value in general outpatient venipuncture. What wasn't addressed was the degree to which familiarity with the technique might affect results. I suspect that if bevel down were to become the norm, future nurses, docs and patients would all find the experience a bit easier.

 
At Thu Sep 28, 07:46:00 PM, Anonymous Pine Baroness said...

I am still going to remember this. My little guy has scars on his arms, hands, legs and feet from IVs and sticks. Information is always useful.
Another time, in a different ER, he was seizing and there were 4 people (2 docs, 2 nurses) each with an arm or leg, trying to establish an IV so they could stop the seizure. I think at that point, any suggestion, even one from a parent, would have been welcome.

#1: the time I mentioned above, my son had a pneumonia in one lung, a fever over 103, he was lethargic and limp. Because of his tone, oral feeding was a challenge on the best days. Back then he didn't have feeding tube, he does now. Taking him home was not the optium thing to do, I would have prefered that he be treated, but it turned out ok.

 
At Thu Sep 28, 07:56:00 PM, Blogger #1 Dinosaur said...

PB: All I can say is, Oy. Glad your son is ok. Best of luck.

 
At Thu Oct 05, 12:02:00 AM, Blogger coturnix said...

I use bevel down when I draw blood out of tiny wing veins in quail. I came up with it by trial and error.

 
At Fri Oct 20, 09:40:00 AM, Anonymous Cardiolcohol said...

I also use this technique but I think there is another reason bevel down works better; you don't puncture the arterial wall as fast. Look at the picture of bevel up; you easily puncture the wall with the sharp point of the needle.

 
At Sun Jun 01, 07:43:00 PM, Anonymous Anonymous said...

Thanks for the tip ~ as an old and well seasoned nurse I am looking forward to trying this new trick! Your diagram makes oodles of sense!

 
At Sat Apr 04, 03:19:00 PM, Blogger drsam said...

Well hello Dr. Dino! I'm a reader via RSS, and today I actually visited your blog and saw your sidebar links, bringing me to this post and now putting my two cents in...

I had never seen this point made before, and as others have said, the method you describe does indeed seem to make sense! But let me play the part of Devil's Advocate and explain why I think "bevel up" has always been taught--there is a reason...

Bevel up is, I think, less traumatic to the skin and soft tissues. Imagine it this way: take your diagram, and move both needles back in time to the point when they are just about to touch skin. Bevel up is piercing with a sharp point, whereas bevel down has a flat surface on the skin, which you then essentially push through. And this happens to epidermis, dermis, lumen, and every layer!

Your point about it then being less likely to pierce the far wall of the vessel is a great one, and maybe skin trauma is a moot point if one can cut down on the number of pierced veins and hematomas. I always try to stay parallel to the skin, which reduces that, but your diagram clearly shows what can happen.

I'd say that I'm going to switch and at least try your way from now on, but truth be told even though I'm much younger than you are I'm already past the point in my career when I'd do any venipuncture myself. Now, if I could only somehow improve the skills of those who draw my blood all too often, that would be something!

 
At Wed Oct 07, 11:21:00 PM, Anonymous Anonymous said...

After reading the article about bevel up or down, I pulled out a couple of cannulas... I believe that the journal mentioned no benefit one way or the other, except in very small or dehydrated children. I offer that one should keep in mind the size of the needle and cannula. Going bevel down with an 20G is a whole different experience than going bevel down with a 24G. I am curious to try though.

 

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