I gave heparin in an insulin syringe, was I right ?

[Nurse Beth, MSN]

Dear Nurse Beth,

Hi. Fairly new LPN working on night shift at assisted living facility after previously working as a school nurse. I have orders to give heparin 1 ml but it’s in an insulin syringe 100 units. 100 units is equal to 1 ml, yes? So I give 100 units? Please tell me I’m correct. Thank you!!

Dear New LPN,

Insulin syringes should only be used for insulin. A U-100 one mL insulin syringe is for use with U-100 concentration insulin, which is 100 units of insulin per 1 mL.

It's possible you gave the right amount, but what's missing here is the dosage. The order should have been for a dose, not a volume. The order for heparin should read something like "Heparin 5,000 units subcutaneously every 12 hrs" not "Heparin 1 mL"

There are numerous concentrations on the market. One mL of heparin may or may not be equal to 100 units of heparin.

• If you were using a heparin concentration of 100 units per mL, you gave 100 units (suitable for a flush).
• If you were drawing from a heparin concentration of 10 units per mL, you gave 10 units.
• If you were drawing from a heparin concentration of 1,000 units per mL, you gave 1,000 units.

When drawing up heparin, use a tuberculin syringe. Better yet, your pharmacy should supply pre-filled syringes for you.

If you are not sure of the calculation, double-check with a colleague, even if you have to call your supervisor who is off duty, or a Pharmacist. I understand staff is limited in many assisted living facilities, but someone should be available to you as a clinical resource.

In many organizations, heparin is classified as a double-check medication.