# Milliunits Math Problem

27 Posts

Can anyone provide help with the following med math problem?

Client is admitted to labor and delivery for a trial induction.

Order reads: Begin Pitocin at 2 milliunits per minute and increase by 1 milliunit every 15 minutes until 3 good contractions every 10 minutes.

Available: 500 mL of normal saline with 30 units of Pitocin.

What rate (mL/hr) should be set on the infusion pump to begin the infusion?

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ljbutler said:
Client is admitted to labor and delivery for a trial induction. Begin Pitocin at 2 milliunits per minute and increase by 1 milliunit every 15 minutes until 3 good contractions every 10 minutes. Available: 500 mL of normal saline with 30 units of Pitocin. What rate (mL/hr) should be set on the infusion pump to begin the infusion?

To do this problem you need to know that Pitocin comes in 10 units per 1 mL and that when this 1 mL is added to 500 mL of IV solution it results in the solution containing 20 milliunits per mL of the IV solution (Reference: page 958, 2007 Intravenous Medications, 23rd edition, by Betty L. Gahart and Adrienne R. Nazareno). Therefore. . .a 500 mL solution with 30 units of Pitocin in it will contain 60 milliunits of the Pitocin.

Dose desired
: 2 milliunits (mU)/minute
Dose on hand
: 30 units/500 mL, or 60 mU/500 mL
500 mL/60 mU
(dose on hand)
x 2 mU/minute
(dose desired)
= 16.666 mL/minute
, rounded off to
17 mL/minute

18 Posts

ljbutler said:
Can anyone provide help with the following med math problem:

Client is admitted to labor and delivery for a trial induction.

Order reads: Begin Pitocin at 2 milliunits per minute and increase by 1 milliunit every 15 minutes until 3 good contractions every 10 minutes.

Available: 500 mL of normal saline with 30 units of Pitocin.

What rate (mL/hr) should be set on the infusion pump to begin the infusion?

Thanks......

Just glad to find this dosage problem in milliunits. here's my answer...

1 Unit = 1000 milliunits (mU)

Dose desired: 2 milliunits/min

Dose on hand: 30 units/500 mL or 60 milliunits/mL (this is the dose concentration)

So: dose desired x dose concentration

2 milliunits/min x ml/60 milliunits = 0.033 mL/min

Set on the infusion pump? 0.033 mL/min x 60 min/hr = 1.9 mL/hr or 2 mL/hr

815 Posts

Yep, that's a good explanation. I did it just a tad bit differently, basically just cancel out the units. But I'm looking at daytonite's explanation, I was wondering if you could explain that, because we got totally different answers..unless I'm wrong, but I thought 1000mu were in 1u

2mu x 1u x __500ml x 60min = 2ml/hr

min 1000mu 30u 1hr