NICU calculation. Please help.

[Pai90]

Hi everyone,

I recently started working in the NICU. I have some questions about a calculation and would appreciate if someone can chime in. The calculation is as follows:

A one time does of Morphine 0.2 mg/IV is to be administered for post operative pain. The available concentration of Morphine is 10mg/1mL. How much medication should be administered?

My answer is 0.02 mL which is correct but since I can't draw up 0.02 in a syringe I was told to draw up 1 mL of Morphine (10 mg) into syringe with 9 mL of sterile water for concentration of 10 mg of morphine in 10 mL will give me 0.2 mL and this I can draw up.

Can someone explain the process of drawing up the 9 mL? Where did they get 9 mL from or how do I know how much mL's to draw up to make the 0.2 mL?

Only positive comments appreciated

Thank you.

[Wuzzie]

You put a needle on a 10 ml syringe and draw up 9ml of sterile water from a vial of sterile water. Then you use the same syringe to draw up the one ml of morphine so you have a total of 10ml of solution in your syringe (9ml of water, 1 ml of medication). You have now changed the concentration of Morphine to 10mg/10 ml or more commonly 1mg/ml. Now redo your calculation with this new concentration and see what you get.

[EGspirit]

Either way, you're probably going to have to waste some morphine, and it depends on how your NICU or whatever allows this to work, but here's what could be done...

Using a 1 ml tuberculin syringe, draw up 0.1 ml (1 mg) of the MSO4

Draw up into that same syringe a further 0.9 ml of sterile water

Your syringe concentration is now 1 mg/ml

You can give 0.2 ml from that syringe or waste, 0.8 ml first to be safe and give what's left.

You could also label a sterile water bottle and make a 1 mg/1 ml supply, if your facility allows for that for later dosing.

Just remove 1 ml from the bottle and add 1 ml of the morphine solution (10 mg/ml) and that would give you a 1 ml/1 mg solution of MSO4

By all means, check your math with another nurse, and if my math is off above, someone correct me before I inject the baby please. :)

[Wuzzie]

Either way, you're probably going to have to waste some morphine, and it depends on how your NICU or whatever allows this to work, but here's what could be done...

Using a 1 ml tuberculin syringe, draw up 0.1 ml (1 mg) of the MSO4

Draw up into that same syringe a further 0.9 ml of sterile water

Your syringe concentration is now 1 mg/ml

You can give 0.2 ml from that syringe or waste, 0.8 ml first to be safe and give what's left.

You could also label a sterile water bottle and make a 1 mg/1 ml supply, if your facility allows for that for later dosing.

Just remove 1 ml from the bottle and add 1 ml of the morphine solution (10 mg/ml) and that would give you a 1 ml/1 mg solution of MSO4

By all means, check your math with another nurse, and if my math is off above, someone correct me before I inject the baby please. :)

Yes you can do it this way in theory but in practice it is nearly impossible to really mix the two well in such a small syringe. You risk overdose. We always mixed in a 10ml syringe for that reason.

[Coffee Nurse, BSN, RN]

Where did they get 9 mL from or how do I know how much mL's to draw up to make the 0.2 mL?

You can theoretically use any volume of diluent, not just 9 mL. However, using volumes of drug+diluent that add up to 10 mL makes it much easier to do the math to get your dose, as you just have to move the decimal point. In this case, you go from 0.02 mL to 0.2 mL.

[Coffee Nurse, BSN, RN]

Just remove 1 ml from the bottle and add 1 ml of the morphine solution (10 mg/ml) and that would give you a 1 ml/1 mg solution of MSO4

This is confusingly worded, but I think you mean taking 1 mL out of the bottle and replacing it with 1 mL of morphine (not adding the morphine to the 1 mL drawn out of the bottle). Either way, I don't think I'd be comfortable having an otherwise-labeled bottle of anything with morphine sitting in it, no matter how well I'd relabeled it.