hello students good morning I'm miss Henderson today I am going to be talking to you I'm gonna
be presenting to you some calculations of obstetric calculations on pitocin and
magnesium sulfate flow rates so let's look at some of our morning objective for this lesson
so upon completion of this lecture student will be able to demonstrate the following competency
ability to safely calculate magnesium sulfate bolus demonstrate competence in calculating flow
rates according to doctor's order demonstrate the ability to calculate the Tosun flow
rates discuss the indication for pitocin and verbalized indications for magnesium sulfate so
so the first problem we have here on the board calculating magnesium sulfate flow rate so the
physician has ordered magnesium sulfate bolus with 4 grams in a hundred milliliters of lactated
ringers solution to be given over 20 minutes what rate should the nurse set the infusion pump so as
you can see I have set up the equation we're looking for xml's per hour so we were giving
the volume we were giving a hundred milliliters in four grams and that is to be infused in 20
minutes so we have a hundred milliliters and we have our time twenty minutes and we know we
in flow rate we're looking for milliliters per hour so we know one in every hour is equal to
sixty minutes so we are ready to solve this problem so we have minutes cancelling out
and we know that 2020 goes into 63 times right we know 20 goes into 63 times so we have three
so then we have three times a hundred is equal to three hundred so we have three hundred milliliters
per hour that's what the nurse is going to program the IV pump to administered so let's look at some
of the indications for magnesium sulfate what are some of the indications for magnesium sulfate sold
some of the indications for magnesium sulfate is that it lowers the blood pressure it's used
to treat preeclampsia a clumsier and it also helped helps to prevent seizure disorder so we
also have some contraindications for magnesium so these are the contraindications so patients that
have impaired renal function it's contraindicated to use magnesium salt sulfate patients with heart
black or myocardial damage it's contraindicated also patients with myasthenia gravis cannot use
magnesium sulfate magnesium sulfate also interacts with nipi nevirapine so it's also contraindicated
so let's look at pitocin so what are some of the indications of of pitocin so we know pitocin is
a hormone right oxytocin and it's really by the posterior pituitary gland so oxytocin is
used in obstetric it helps to increase uterine contraction it facilitates cervical dilatation
it helps to facilitate vaginal delivery it increased bonding within the mom and
the fetus it stimulates milk ejection for breast feeding it also reduces stress that
may contribute to postpartum depression so those are some indications for oxytocin so let's look
at another problem here so we have here magnesium flow rate magazine magnesium sulfate 40 gram in a
thousand milliliter of lactated ringers at a rate of 2 grams per hour what is the pump rate so what
would the nurse set the pump so we are looking again for flow rate which is milliliters per
hour so using dimensional analysis we are going to set up the equation so XML per hour equal to
we were giving a thousand ml of lactated ringers that sort of volume and with a thousand MLS per
hour and we also within that thousand we have 40 grams so we have 40 grams here right and then the
ringer at a rate of 2 grams per hour so we have every 2 grams in 1 hour so now we have grams
cancelling out with grams we have to
goes into 40
we have Z we have we can cancel zero here we can cancel another zero here
and we left with two goes into 4 into 4 2 times we have 2 here and 2 goes into a
hundred how many times 50 times so we have 50 milliliters per hour that's what the nurse is
going to program the IV pump to deliver so let's look at a another problem so pitocin flow rate
calculation the physician has ordered 2 million units per minute pitocin is available with 10
units per ml protocol on the L&D unit mix two vials per a thousand ml of normal saline what
should the nurse set the IV pump at so we know in every in one unit it's equal to a
thousand million 'its we also know 60 minutes is equal one error because that was given to us
in the problem so now we have we're looking for what flow rates right so we have one unit is in
a thousand million units and we have one hour is equal to sixty minutes and
it was given to us a physician has all a 2 milli units so we have two
million units per minute times the the volume the vial which is a thousand ml
and protocol states two vials of ten units so if we have two vials of ten
unit which is 20 units we have 20 units in a thousand of ml so now
we are ready to solve the problem we have million units canceling out
we have mints cancelling out with minutes we have units
units canceling out with units so now we have here sixty times two times a thousand divided
by 1,000 or we can even cancel this out one thousand into one thousand is one we have also
twenty into sixty it's three and then we have 3 times 2 which is 6 that gives us six milliliters
per hour and that's what the nurse is going to program the pump to deliver so let's look at
another problem guys so in this in this question here the physician has ordered 500 milliliter of
d5w with ten units of IV oxytocin begin at two million units per minute and then increased by
one milli units per every 30 minutes until regular uterine contractions begin maximum
dose is 30 million units per minute so the first aspect of the problem is asking us what is the IV
flow rate for the beginning infusion so let's solve this so we're looking for milliliters
per hour so using dimensional analysis we can set up the equation to solve for x ml
per hour so we were giving the fuzziness order 500 milliliters in 10 units so we know 500 goes
with 10 units and we know one unit is equal to 1000 million --it we were also given beginning
infusion at 2 milli units per a minute and we know one hour is equal to 60 minutes so
now we are ready to solve this equation so we have minutes and minutes cancelling out we have
many units and milli units canceling out we have units and unit canceling out so we have here 500
times two times 60 or we can go ahead and cancel 10 goes into 60 six times right we
have 500 goes into a thousand how many times two times so if you do the calculations you should
have six milli six milliliters per hour which is the beginning infusion rate now that other
elements of the problem is asking what is the IV flow rate for the maximum infusion so it's
the same concept setting up the equation we have our milliliters per 10 units and we were given
the maximum dose is 30 milli units so we have 510 in 10 units one unit is a thousand million
units and the max the maximum dose is stirred 30 milli units per minute and one hour is 60
minutes so if you do the calculation the maximum infusion rate should be 90 moly liters per hour so
so I wanted to really do this short scream o matic - you know deepen your understanding of
the obstetric calculation for mass for med and you are 103 I hope you find this short presentation
engaging and I hope it helps to enhance your knowledge in obstetric calculation so I have
some practice problems in the remainder of the slides so you can have fun doing those and I also
indicate the answers for most of them thank you so much and see you in the next lecture bye for now
you