Hematoma formation after saphenous blood draw on a cat

[Ayemee]

Hi guys!

I have found cats saphenous veins are very prone to hematomas, why is this and how can I try to prevent them?

Also...if the cat has low blood pressure and the blood draw is really slow, yet; a hematoma is forming, is it best to pull out and start over?

---

Members don't see this ad.

 

[WildZoo]

Hi guys!

I have found cats saphenous veins are very prone to hematomas, why is this and how can I try to prevent them?

Also...if the cat has low blood pressure and the blood draw is really slow, yet; a hematoma is forming, is it best to pull out and start over?

If it starts forming while you're still getting the blood, you've blown the vein. So yeah, I would usually pull out, put pressure on that spot, and try higher up once the initial site has clotted.

Have you tried using a smaller gauge needle or a smaller syringe? And making sure you're holding off the vein after you're done? That site is also really only good for getting 1-2mL, so if you need more you should be using the jugular or cephalic.

 

[pinkpuppy9]

If it starts forming while you're still getting the blood, you've blown the vein. So yeah, I would usually pull out, put pressure on that spot, and try higher up once the initial site has clotted.

Have you tried using a smaller gauge needle or a smaller syringe? And making sure you're holding off the vein after you're done? That site is also really only good for getting 1-2mL, so if you need more you should be using the jugular or cephalic.

Completely agree with this. Personally I hate using the saphenous in a cat. I only turn to the saphenous if the cat is aggressive and I don't think I have enough/any kitty minutes to get the jug. Either way, dog or cat, try to hold off for as long as possible even if you don't see a hematoma yet. If you see a hematoma, apply pressure for like a minute+. If no hematoma, usually 15 seconds or more is pretty good. I see a lot of people pull out, put their thumb over the site for a second or two, then walk away and wonder why the patient is still bleeding or a hematoma formed.

Completely anecdotal, but it seems (IME) that saphenous pokes are more painful for cats than other blood draw sites. Not sure why, but I've had cats scream for the saphenous poke and be extremely difficult to hold (therefore ruining the draw), and then be perfectly fine when we move to the jug. Could be the lateral restraint, but some of the cats are perfectly fine until they feel that poke.

TLDR: Saphenous sticks are my last choice unless the cat is going to maul me.

 

[WhtsThFrequency]

I feel like the restraint is a big part of why cats hate saphenous sticks. Especially people holding and extending the hind leg part. My cat (a calico/tortie no less) is incredibly patient for all other examination procedures....but as soon as you touch the back jellybeans, oh man....you're gonna get some colorful language.

 

[WildZoo]

Yeah, I mean, I got pretty good at them because it was standard procedure at the last place I worked (and I think people like them because you're far away from the cat's teeth and front claws), but it by far requires the most intense restraint of any of your typical blood draw methods, which is a good way to drain any kitty minutes you might have left. I imagine the positioning alone can make them feel really vulnerable/uncomfortable.

 

[Trilt]

I don't trust most of my assistants to hold appropriately for jug sticks in cats and almost exclusively use the medial saph. I've recently switched to using it for most of my anesthesia catheters, too. A lot of cats are much less upset by it if you let them sit their front half upright instead of jumping straight to scruffing and stretching, and for caths EMLA cream makes it a breeezzeee.

Just get better at poking. If you get it in one fluid motion and don't wriggle too much, you're much less prone to horrible hematomas. I mean some veins just suck. but not all of them.

 

[DVMDream]

I love me the medial saphenous.

I can get jug sticks on cats as well, but I think more cats hate their head/face being squished and front legs being stretched than they do having a back leg pulled out.

I just wrap the front half in a blanket if needed, without scruffing, just let the cat be... and then poke the saphenous. I can easily hit that vein 99% of the time with minimal to no bruising/hematoma formation and I can easily get 3-6mLs of blood. Just takes practice and a lot of butterfly catheters as they work best for this vein. I hate watching techs draw with a needle/syringe off the saphenous in cats... it fails easily 95% of the time and then I have to step in after they have poked 2-3 times and use the butterfly which works beautifully (nearly) every time. I honestly think a syringe directly on this vein is too much for the vein to handle and it collapses, having that butterfly really helps. Also, if I have a ****ty/dehydrated kitty, I will draw back with a 1mL syringe and just use multiple of them, can easily remove from butterfly and put a new one on.

 

[WildZoo]

I don't trust most of my assistants to hold appropriately for jug sticks in cats and almost exclusively use the medial saph. I've recently switched to using it for most of my anesthesia catheters, too. A lot of cats are much less upset by it if you let them sit their front half upright instead of jumping straight to scruffing and stretching, and for caths EMLA cream makes it a breeezzeee.

Just get better at poking. If you get it in one fluid motion and don't wriggle too much, you're much less prone to horrible hematomas. I mean some veins just suck. but not all of them.

I've never seen anyone do it where you don't do the full scruff and stretch! This is magical information.

 

[Ayemee]

I love me the medial saphenous.

I can get jug sticks on cats as well, but I think more cats hate their head/face being squished and front legs being stretched than they do having a back leg pulled out.

I just wrap the front half in a blanket if needed, without scruffing, just let the cat be... and then poke the saphenous. I can easily hit that vein 99% of the time with minimal to no bruising/hematoma formation and I can easily get 3-6mLs of blood. Just takes practice and a lot of butterfly catheters as they work best for this vein. I hate watching techs draw with a needle/syringe off the saphenous in cats... it fails easily 95% of the time and then I have to step in after they have poked 2-3 times and use the butterfly which works beautifully (nearly) every time. I honestly think a syringe directly on this vein is too much for the vein to handle and it collapses, having that butterfly really helps. Also, if I have a ****ty/dehydrated kitty, I will draw back with a 1mL syringe and just use multiple of them, can easily remove from butterfly and put a new one on.

I need to work on my butterfly technique, that’s something I’ve been wanting to get better at for awhile. If you need less than a ml of blood, do you still use the butterfly for a saphenous vein? I feel like I would get scowled at for using a butterfly to get less than a ml of blood. Haha

 

[CalliopeDVM]

I love the medial saphenous for blood draws as well as injections! I find that cats are actually better behaved than for cephalic blood draws when we're not up close in their face, but that might be about the restraint technique (?). I agree that about 1-2 mL is the limit for a single withdrawal, though, and if you do only need a little, choose a 1 cc syringe rather than a 3 cc syringe.

 

[Minnerbelle]

I agree it's 100% about the restraint. The standard stretch out cat and pull out front legs off the table approach for the jug is so very stressful for cats. I do 90% of my cat draws on jugs, but never with that approach. For a super easy going cat, I just let them sit and have someone gently hold the head up. For everyone else, I have them in lateral recumbency and have someone gently keep the head straight by holding the zygomatic arches. Neither approach messes with their feet, or tension in your hands that cats pick up on and get pissed about. The way the drawer uses alcohol and feels for the vein and holds off the thoracic inlet, and how you gently but firmly get the needle through the skin/vein in one swift motion is also key. When a good kitty handler does it, kitty is calm and doesn't react. For everyone else, I see kitties flinching with every touch and it makes me cringe. With a lateral jug, if kitty's front paws are a little too handsy, you can burrito kitty very well and still access everything you need. You also need someone who can hit the jug in one poke 90+% of the time. But for the restrainer, it's not hard and you don't need the kitty whisperers touch to not piss cat off since there's minimal touching of the cat. Sometimes if my techs/assistants are taking too long and I have a really good cat, I can get blood on my own with this approach.

Then for any other vessel, I use a 23g butterfly with 1 or 3 cc syringe depending on how flimsy the vessel looks. For arthritic cats who don't like having their backends touched, or angry kitties who will wear a cup muzzle without getting extra pissed, I'll use a cephalic for a quicker draw as long as it's not a cat who may need an IV cath in the near future.

If I have a vein and is starting to blow but blood is flowing really well, I'll keep going, but otherwise it's game over ASAP. And the most important thing is that someone puts the flat of their finger right on the hole and another finger around the leg, and doesn't let go and keep those fingers in place as the cat retracts it's leg. I find the most common problem is that people let the cat pull leg in and lose the spot.

 

[JustPaws]

Love a butterfy vacutainer for med saph, otherwise I'm with MinnerB and prefer the jug. All about giving kitty time to settle into position before I touch.

And for OP, are you using a bandage? Essential, and make sure your holder doesn't just let go immediately.

 

[DVMDream]

I love the medial saphenous for blood draws as well as injections! I find that cats are actually better behaved than for cephalic blood draws when we're not up close in their face, but that might be about the restraint technique (?). I agree that about 1-2 mL is the limit for a single withdrawal, though, and if you do only need a little, choose a 1 cc syringe rather than a 3 cc syringe.

Why is 1-2mLs the limit for a saphenous? It isn't any smaller than the cephalic. It can hold a catheter. Why can't you draw more than 2mLs from it? I don't see a big deal getting 3 or more mLs from it as long as it is flowing well, not blowing and kitty is handling the draw fine.

I think most people get too antsy and yank back on the syringe plunger thus collapsing the vein and only getting a couple mLs or less before it "doesn't flow well"... that's why I slowly draw or switch to a 1cc syringe (and draw into 3 syringes)... it puts less pressure on the vein and it tends not to collapse.

I've never not been able to get a solid 3cc's from a cat saphenous...which is the amount usually needed to fill tubes being sent out to the lab.

 

[DVMDream]

I need to work on my butterfly technique, that’s something I’ve been wanting to get better at for awhile. If you need less than a ml of blood, do you still use the butterfly for a saphenous vein? I feel like I would get scowled at for using a butterfly to get less than a ml of blood. Haha

I always use a butterfly, unless we're talking kitten felv/fiv testing....then I use an insulin syringe. But, in general, I don't like the straight off the needle/syringe combo...

 

[DVMDream]

I need to work on my butterfly technique, that’s something I’ve been wanting to get better at for awhile. If you need less than a ml of blood, do you still use the butterfly for a saphenous vein? I feel like I would get scowled at for using a butterfly to get less than a ml of blood. Haha

I should also say that I rarely draw less than 3mLs of blood. It is much easier, especially with cats, to get more than you might need to start. Rather than finding out later that you need more blood because something was abnormal and you don't have enough for additional testing. Then you have to poke kitty again. I always a get at least 3mLs... in a decent sized cat they won't miss the extra 1-2mLs of blood. ..heck in most cats it isn't a big deal. The only time I really don't is for felv/fiv testing....I'll get enough just for that test.

 

[CalliopeDVM]

Why is 1-2mLs the limit for a saphenous? It isn't any smaller than the cephalic. It can hold a catheter. Why can't you draw more than 2mLs from it? I don't see a big deal getting 3 or more mLs from it as long as it is flowing well, not blowing and kitty is handling the draw fine.

It may not be smaller than the cephalic (though I think it is), but it seems to fill slower (maybe it's the blood pressure?).....maybe that's because I don't yank back the plunger and collapse the vein So, it's more likely you're going to get a clot if you draw for too long, which is a problem if you're drawing for a panel that includes a CBC. The cat is usually willing to give more, but what you can use it for is limited by the blood's willingness to clot.

 

[DVMDream]

It may not be smaller than the cephalic (though I think it is), but it seems to fill slower (maybe it's the blood pressure?).....maybe that's because I don't yank back the plunger and collapse the vein So, it's more likely you're going to get a clot if you draw for too long, which is a problem if you're drawing for a panel that includes a CBC. The cat is usually willing to give more, but what you can use it for is limited by the blood's willingness to clot.

I haven't had an issue with it clotting drawing up more than 2mLs....

But I also disconnect after I get the first mL and place that into a lavendar top tube, then continue to draw the remaining 2mLs. There are definitely ways around that problem. Definitely fills slower, especially in the ancient, dehydrated, raisin renal failure kids... but still haven't had an issue drawing 1mL at a time and passing off syringes to the techs to fill the tubes. Maybe I have just gotten lucky.

I rarely ever draw less than 3mLs of blood regardless of the vein used. I need blood, I am getting as much as I possibly can. There's no hard and fast rule that you can only draw x mLs from y vein.

 

[pinkpuppy9]

It may not be smaller than the cephalic (though I think it is), but it seems to fill slower (maybe it's the blood pressure?).....maybe that's because I don't yank back the plunger and collapse the vein So, it's more likely you're going to get a clot if you draw for too long, which is a problem if you're drawing for a panel that includes a CBC. The cat is usually willing to give more, but what you can use it for is limited by the blood's willingness to clot.

Have you tried heparinizing your syringe? I feel like heparin is an underutilized tool.

To each their own. Unless the cat is really bad, I usually ask for minimal restraint (partial purrito with the cranial half wrapped, but some cats really just react terribly to their leg being manipulated however gently or poked. Idk. (inb4 sticking technique-I've seen it happen to seasoned techs/clinicians on who knows how many cats, not just me)

 

[DVMDream]

Have you tried heparinizing your syringe? I feel like heparin is an underutilized tool.

To each their own. Unless the cat is really bad, I usually ask for minimal restraint (partial purrito with the cranial half wrapped, but some cats really just react terribly to their leg being manipulated however gently or poked. Idk. (inb4 sticking technique-I've seen it happen to seasoned techs/clinicians on who knows how many cats, not just me)

Can't heparinize a syringe if you're pulling for chemistries and if using a butterfly you could technically get a clot in that line before it goes into the syringe.

 

[pinkpuppy9]

Can't heparinize a syringe if you're pulling for chemistries and if using a butterfly you could technically get a clot in that line before it goes into the syringe.

You can run a plasma chemistry though. It's always been an option for any Idexx chem I've seen, not sure about other external labs. Just gotta let the lab know what your sample is/interpret accordingly I assume. And I've seen people heparinize butterflies before but it probably depends on the sample size you're aiming for

 

[DVMDream]

You can run a plasma chemistry though. And I've seen people heparinize butterflies before but it probably depends on the sample size you're aiming for.

Plasma chemistries create a lot of abnormal results, much better to avoid if possible.

 

[pinkpuppy9]

Plasma chemistries create a lot of abnormal results, much better to avoid if possible.

I've always been taught that as long as you ID the sample as plasma/interpret with the proper reference intervals or at least recognize the artifact, you're fine, because it's not that it's creating 'abnormal' results so much as people still use serum normals to interpret plasma. @JaynaAli do you have any opinions on this? I mean obviously do the serum if you can because it's easier to interpret quickly since that's what everyone is used to, but I've had a clin pathologist say plasma chems are fine as long as you interpret accordingly, and that it's mostly just potassium and protein that are reliably going to be different than serum in most analyzers.

Out of curiosity, I skimmed a few papers on the subject and people seem to be pretty 50/50 as to whether or not the differences are statistically significant, and most of the papers I read (just the abstract tbh) said the differences weren't medically significant. I'm not saying we should all start running plasma chems or anything, I've just been taught that it's an option that can come in handy if for some reason you can't get more blood. Maybe I've been taught horribly wrong, idk.

 

[DVMDream]

I've always been taught that as long as you ID the sample as plasma/interpret with the proper reference intervals or at least recognize the artifact, you're fine, because it's not that it's creating 'abnormal' results so much as people still use serum normals to interpret plasma. @JaynaAli do you have any opinions on this? I mean obviously do the serum if you can because it's easier to interpret quickly since that's what everyone is used to, but I've had a clin pathologist say plasma chems are fine as long as you interpret accordingly, and that it's mostly just potassium and protein that are reliably going to be different than serum in most analyzers.

Out of curiosity, I skimmed a few papers on the subject and people seem to be pretty 50/50 as to whether or not the differences are statistically significant, and most of the papers I read (just the abstract tbh) said the differences weren't medically significant. I'm not saying we should all start running plasma chems or anything, I've just been taught that it's an option that can come in handy if for some reason you can't get more blood. Maybe I've been taught horribly wrong, idk.

Potassium and protein are important pieces of information to have and to know if they are abnormal, using plasma eliminates having a good reference for those. Just not worth it, IMO, just run the serum.

That doesn't even touch upon having techs that would know the difference, know to change the machine, making sure you have a machine that can run plasma, etc.

 

[JaynaAli]

I think a big differentiating factor is an in-house lab versus a send-in lab. If DVMD were to send out a plasma chemistry, I am doubtful that it would be spun down in her clinic and aliquot-ed off into another tube. So probably [and maybe I'm completely wrong], she (aka her techs) would be sending in an un-spun sample, which is certainly prone to error (especially glucose, but also things like potassium, protein, and heck even ALT/AST if we're talking a hemolyzed sample) so it is probably better to submit a serum sample if there is going to be any delay in analysis. It's a lot easier and saves time/supplies to just spin down your SST and not have to aliquot it off into a second tube. On the other hand, a lot of your experience is in exotics, where we are so concerned about sample volume that you need every single drop and we're willing to sacrifice that improved accuracy for the sake of getting more values. The same might not be true when tracking a CKD cat over time where the actual number matters. I never had a problem getting enough from a butterfly for a CBC and I've never heparinized anything in my life. Plus if people put too much liquid in their syringe heparinizing it, it can dilute your values too...better not to risk it imo.

 

[Caia]

I don't think I've ever drawn blood on a cephalic. It feels too much like sacrilege to draw on the precious IVC veins.

 

[Trilt]

I don't think I've ever drawn blood on a cephalic. It feels too much like sacrilege to draw on the precious IVC veins.

Digression, but I actually almost exclusively put my short term anesthesia caths in the medial saphenous in kitties recently. The shave spot is nicely hidden, they don't care as much when placing it, and it works just as well. I had a run of really **** veins where me and my (very very experienced!) tech had several blown cephalics in a row and I had to resort to a back leg, and I eventually was like... why don't I just always do this?

So I did. It really works nicely. If they're gonna be on fluids or hospitalized for a couple days I still do the front leg because they're less likely to tuck and kink it (in my hands at least) but for just induction and "oh ****" caths, I really kinda love the back legs.

Also almost never draw from cephalics besides in big dogs.

 

[Caia]

Digression, but I actually almost exclusively put my short term anesthesia caths in the medial saphenous in kitties recently. The shave spot is nicely hidden, they don't care as much when placing it, and it works just as well. I had a run of really **** veins where me and my (very very experienced!) tech had several blown cephalics in a row and I had to resort to a back leg, and I eventually was like... why don't I just always do this?

So I did. It really works nicely. If they're gonna be on fluids or hospitalized for a couple days I still do the front leg because they're less likely to tuck and kink it (in my hands at least) but for just induction and "oh ****" caths, I really kinda love the back legs.

Also almost never draw from cephalics besides in big dogs.

We've found that they don't seem to tape in well and like to come out but I may be mostly doing the longer term catheters.