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.)
There are NOT any 5 ml TB syringes and there are NOT any 5 ml Insulin syringes.
If you had to give 34 units of U100 Insulin in a 1 ml Insulin syringe you would extract exactly 34 units of Insulin into the syringe.Check this on the EVEN numbered side of the syringe. If you check on the other side of the syringe you would get a misreading due to the ODD numbers on that side.
If you had to give the 34 units of Insulin using a 1 ml TB syringe you would extract 0.34 mls of insulin.
34/100ths on a TB syringe = 34 units of U100 Insulin.
In the US we still use 50 or 100 unit/cc insulin syringes so you MUST check your doses and try to avoid using a TB syringe at all. USE THE INSULIN SYRINGE unless you are very very VERY good at calculating dosages and conversions.
I tend to agree with daytonite about the measurement calculation. My tuberculin syinge says the same graded measurements on each side and goes up to a mL altogether. each ten graduations is 10, 100 ths . ie it goes 0.1, 0.2 etc until it gets to 1 ML. So for 34 units it would be up to 3 and the graduation just prior to the halfway mark. Do yours differ in the US?. We were told to tuberculin syringes accurate measurements. I haven't had to use them for a while as at the Nursing home most of our diabetic clients have novopens.
sdprcrn
11 Posts
There are NOT any 5 ml TB syringes and there are NOT any 5 ml Insulin syringes.
If you had to give 34 units of U100 Insulin in a 1 ml Insulin syringe you would extract exactly 34 units of Insulin into the syringe.Check this on the EVEN numbered side of the syringe. If you check on the other side of the syringe you would get a misreading due to the ODD numbers on that side.
If you had to give the 34 units of Insulin using a 1 ml TB syringe you would extract 0.34 mls of insulin.
34/100ths on a TB syringe = 34 units of U100 Insulin.
In the US we still use 50 or 100 unit/cc insulin syringes so you MUST check your doses and try to avoid using a TB syringe at all. USE THE INSULIN SYRINGE unless you are very very VERY good at calculating dosages and conversions.