Insulin dosaging with proper syringe choice

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First semester RN student here. We're currently going over Insulin and Heparin dosaging, as well as general medication calculations. There is a practice question in some material that our class has been given that I am stumped on.

The question reads (and this is verbatim):

"Ordered: Lente insulin 34 units sq q am. Avaliable is a tuberculin syringe. How many mL will you measure? Avaliable is a 5 mL insulin syringe. How many mL will you measure? ______ "

What I am confused about is the second question - regarding the "5 mL insulin syringe". I wasn't even aware that there was such a thing. I thought that all insulin syringes are either Standard U-100, 50-U Lo-Dose U-100, or 30-U Lo-Dose U-100; and, more importantly, that regardless of which one you're using, 1 Unit = 0.01 mL. (ie, 100 Units = 1 mL). Correct?

Now if that is the case, why would you want to even use a 5 mL syringe in the first place? Would a "5mL insulin syringe" be properly graded to accomodate a measurement as precise as 34 units? And if so, wouldn't the answer simply be the same as the answer to the first part of the question - ie, 0.34 mL? (And if not, then what would your answer be? I know that you are never supposed to "round off" when doing insulin dosages...so what gives?? lol.)

Thanks in advance for your time and replies ! :)

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Specializes in med/surg, telemetry, IV therapy, mgmt.

i think you are right. i also think the question you were given has a typo in it. i'm looking at my cat's insulin syringes (she's diabetic and on insulin) and her syringes are labeled as holding "3/10th's of a cc for 30 units or less" [of u-100 insulin]. each syringe actually states on it that it is 3/10th's of a cc. these are what we call mini-insulin syringes because i know there are insulin syringes that hold larger units of insulin. i'm thinking that your problem probably should have read "0.5 ml insulin syringe" (or 1/2 ml capacity of the syringe) which would accommodate 50 units of insulin. that makes more sense to me, but i don't have that size of insulin syringe around here to actually look at to confirm that. maybe there is someone who has an insulin syringe of that size that can verify this for us.

btw, i haven't seen u-40 and u-60 insulin in years!!! u-100 was brought on the scene when i was a new grad (back in 1975) and i remember having to carefully check bottles of insulin and the syringes i was using because we had vials of all these different insulin strengths. i think the u-40 and u-60 has finally been pulled off the market. they're probably just making you learn this stuff because it's something they've been making students learn for years. you'll probably never see it in actual practice though.

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i think you are right. i also think the question you were given has a typo in it. i'm looking at my cat's insulin syringes (she's diabetic and on insulin) and her syringes are labeled as holding "3/10th's of a cc for 30 units or less" [of u-100 insulin]. each syringe actually states on it that it is 3/10th's of a cc. these are what we call mini-insulin syringes because i know there are insulin syringes that hold larger units of insulin. i'm thinking that your problem probably should have read "0.5 ml insulin syringe" (or 1/2 ml capacity of the syringe) which would accommodate 50 units of insulin. that makes more sense to me, but i don't have that size of insulin syringe around here to actually look at to confirm that. maybe there is someone who has an insulin syringe of that size that can verify this for us.

btw, i haven't seen u-40 and u-60 insulin in years!!! u-100 was brought on the scene when i was a new grad (back in 1975) and i remember having to carefully check bottles of insulin and the syringes i was using because we had vials of all these different insulin strengths. i think the u-40 and u-60 has finally been pulled off the market. they're probably just making you learn this stuff because it's something they've been making students learn for years. you'll probably never see it in actual practice though.

wait a minute...your cat has diabetes??

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Specializes in med/surg, telemetry, IV therapy, mgmt.
Wait a minute...your CAT has diabetes??

Yes. When she was in for her yearly checkup two years ago, the vet did labwork on her and her blood sugar was 600! She was started on NPH insulin. She gets blood sugars done with a glucose monitor if I want to check her blood sugar. I either prick her in the ear or the pad of her foot. She's very good about getting her insulin shots and never flinches. FYI. . .insulin stinks. I mean it literally smells bad. I've dropped the vials on the floor twice (I have some neuropathy in my hands) and broken them and the smell was awful. She currently gets 3 units of NPH twice a day. She gets them just behind her front elbone (elbow). I have Karo syrup on hand in case of an insulin reaction, but that has never happened. She's too big an eater and the vet has her blood sugar stabilized at around 200. The sad thing is that is costs me $50 a day to board her because they have to put her in kitty intensive care since she needs to get her shots twice a day. When I was in the hospital for 11 days 3 months ago she got sicker than me in there and ended being confined longer than I was! So, now I just take her with me when I go traveling to save money. Motels only charge $25 extra for her to stay. I love this cat, kiddo. She's 14 years old. I got her as a pregnant stray and she had her illegimate litter of 3 kittens in my lap (I'm not kidding) before she was spayed.

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Yes. When she was in for her yearly checkup two years ago, the vet did labwork on her and her blood sugar was 600! She was started on NPH insulin. She gets blood sugars done with a glucose monitor if I want to check her blood sugar. I either prick her in the ear or the pad of her foot. She's very good about getting her insulin shots and never flinches. FYI. . .insulin stinks. I mean it literally smells bad. I've dropped the vials on the floor twice (I have some neuropathy in my hands) and broken them and the smell was awful. She currently gets 3 units of NPH twice a day. She gets them just behind her front elbone (elbow). I have Karo syrup on hand in case of an insulin reaction, but that has never happened. She's too big an eater and the vet has her blood sugar stabilized at around 200. The sad thing is that is costs me $50 a day to board her because they have to put her in kitty intensive care since she needs to get her shots twice a day. When I was in the hospital for 11 days 3 months ago she got sicker than me in there and ended being confined longer than I was! So, now I just take her with me when I go traveling to save money. Motels only charge $25 extra for her to stay. I love this cat, kiddo. She's 14 years old. I got her as a pregnant stray and she had her illegimate litter of 3 kittens in my lap (I'm not kidding) before she was spayed.

Kitty intensive care??....*bewildered*... :lol2: :o

We've had a lot of sick pets at my house over the years - mostly broken/missing limbs...I just didn't think cats ever GOT diabetes in the first place. I thought it was solely a human problem. Don't cats (and dogs) normally prefer to be left alone while they're giving birth?

Anyway, thank you for your feedback on my question. You must be right about it being a typo for "0.5". I have no idea what else it could be.

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Specializes in med/surg, telemetry, IV therapy, mgmt.

Cats are mammals. Many mammals have similar anatomy and physiology to humans. Many drugs are tested on these animals before they are given to humans. And, yes, cats and dogs can be diabetic. A poem my uncle used to read to us when we were kids was called "The Piddling Pup" and was about a dog with diabetes who had polyuria. I have sometimes posted a link to it as a joke for students to remember polyuria as a symptom of diabetes. The poem is cute.

A farmer's dog once came to town,

His Christian name was Pete,

His pedigree was two yards long,

His looks were hard to beat.

And as he trotted through the town,

'Twas beautiful to see,

His work on every corner -

His work on every tree.

For he watered every gateway,

And he never missed a post,

For piddling was his masterpiece,

And pissing was his boast.

The city dogs stood looking on

With deep and jealous rage,

To see a simple country dog

The piddler of the age.

They sniffed him over one by one,

They sniffed him two by two,

And noble Pete in high disdain

Stood still 'til they were through.

Then Pete to show the city dogs he didn't give a damn,

Walked into the grocer shop and piddled on the ham-

Piddled on the onions,

Piddled on the floor,

And when the grocer kicked him out,

He piddled on the floor.

So all the dogs from far and wide,

Decided what they'd do,

They'd have a piddling carnival

And see the stranger through.

They'd show him all the piddling posts

They knew around the town,

Then started off with many winks,

To wear the stranger down.

For they called the champion piddlers

Who were always on the go,

Who sometimes have a piddling comp

Or hold a piddling show.

They sprang these on him suddenly

When halfway through the town,

But Pete just piddled on and on

And wore their champions down.

For Pete was with their every trick

With vigor and with vim,

A thousand piddles more or less

Were all the same to him.

And on and on went noble Pete

To water every sandhill

Till all the city champions

Were piddled to a standstill.

Then Pete, an exhibition gave

Of all the ways to piddle,

Like double drips and fancy flips

And now and then a dribble.

And all this while the country dog

Did never wink or grin,

But piddled blithely out of town

As he had piddled in.

The city dogs said,"So long, Pete,

Your piddling did defeat us."

But no one ever put them wise -

Poor Pete had diabetes.

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well i got up and scrummaged? is that a word? and looked for an syringes i could find I use the pump now so i don't keep many syringes around but all I found would point to what DTN said.. actually the only ones i found was the 1 ml one's that the pharmacy guy gave me after i begged. It was a holiday... my pump malfunctioned right around the time all things were closing down... i had 1 syringe on stock... we went to 6 store before finding this pharmacy still open... i did everything i could to show this guy that I was diabetic... but as luck would have it i had left my pump at home. I gave him my glucose meter... then i was like i can show him my drivers license! but then i realized hey... i have gotten meds here before... they should be able to look it up... alas! but... of course I had just gotten married..and we had a name change problem... thinking on my feet once again i said well.. call the phone number on file... it'll be my cell... and *ring ring* i prove my self... and he sells me these funny syringes...which leads to this story! lol

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couldn't it also mean 5ml tuberculin syringe? since that's all they have available? someone just got confused since they were talking about insulin in the beginning maybe?

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Specializes in Med/Surg, Tele, IM, OB/GYN, neuro, GI.

I would check with my instructor. It could be a typo or a trick question. There are no 5 ml tuberculin syringes they only got to 1 ml. We had a question similar to that and the answer was you had the wrong supplies to get a insulin syringe and give the med. The people who answered give it in the tuberculin syringe were wrong because you are to draw insulin up only in insulin syringes.

Just make sure that when you ask you know why you're asking the instructor. I would say somethin like I never heard of a 5ml TB syringe but aren't you only able to give insulin in a insulin syringe and see what the instructor says. If we don't have a reason to ask the question or tell them why we think it should be that way our instructors really won't help us inless it is a typo.

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I am holding a Insulin syringe and it says it holds 100u or 1 ml, so I would say 1u is 1/100 of a ml and if you used a TB syringe you would draw up .34ml which I don't know if you can do w/ a TB syringe. When I draw up 34u of air in my insulin syringe it actually says .37ml on the other side of the barrel.....actually it is 1/2 way between .36 and .37ml. I think I would find an insulin syringe!:lol2:

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i might give a two part answer, an answer to the question "AS STATED".... and the anwer about not giving insulin in anything but an insulin syringe////

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Specializes in aged -adolescent.

Don't know if this helps either and has probably been posted but I was told to use a tuberculin syringe which is very thin, graduated finely and goes up to 1 ML

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