Question

Pitocin is ordered for a patient to induce contractions. The order reads: Pitocin (oxytocin) IVPB- start at 2mU/min and increase 1-2 mu/min q 20-30 min until the patient is in active labor. You have available from the pharmacy: Pitocin (oxytocin) 30 units in 500 mL of LR. How many mL/hr would you start the infusion. Remember: *mu(milliunits) milli=1000

Answer 1

Prescribed order of Pitocin = 2 mU /min and increase 1-2 mu/min q 20-30 min until the patient is in active labor

Available dose of Pitocin = 30 units in 500 mL of LR

Pitocin to be infsed when infusion is initiated = 2 mU/min = 2 x 60 = 120 mU/hr = 120$\div$ 1000 = 0.12 units/hr

Desired dose = 0.12 units/hr

Available dose = 30 units

Total volume of the solution = 500 ml LR

Formula method:

ml/hr =( Desired dose $\div$ Available dose ) x Total volume of the available dose

=( 0.12 $\div$ 30 ) x 500

=2 ml/hr

Dimensional analysis:

ml/hr = 500 ml $\div$ 30 units x 0.12 units $\div$ 1 hour

units gets cancelled and multipy the rest

ml/hr =( 500ml x 0.12) $\div$ 30

= 2

The nurse should start the Pitocin infusion at 2 ml/hr