ob meds and calculations

[reddellrn]

im very excited, i applied for a job in ob moday, and that afternoon hr called me and offered me the job. Of course i said yes. Heres the problem. I worked in Home Health for a few years and we do not give very many iv meds. I have not done calculations in years. I wanted to be familiar with meds used in ob and how to do the calculations. I want to be prepared. Any help would be greatly apreciated.

[CEG]

There really aren't very many calculations to be done. There are IV antibiotics, usually run over 30 minutes so that is pretty easy- multiply the volume to be infused by two and you have your rate.

Pitocin can be a little more difficult depending on the dilution that is used. The first facility I worked in it had to be multiplied by 3- so three on the pump was 1 m/u of pitocin. The next facility diluted it one to one so 1 on the pump was 1 m/u.

Mag sulfate is probably the only tricky one- just in terms of determining the bolus and maintenance rates. But that will also depend on the facility and the orders you have.

So nothing that you will find too challenging as an experienced nurse. Everything is on the pump most of the time unless you are just running fluids.

[reddellrn]

thanks for helping. I think ill be ok with the antibiotics, just worried about pitocin and mag. In school m/u was not in the calculation book.

[NurseNora, BSN, RN]

Milliunits/min is never in the calculation book. If you put 3 amps (30 Units) in 500cc it works out to 1mU/min=1ml/hr on the pump. If your hospital isn't using that dilution, try to get them to change. Since there are no calculations, it's harder to make a mistake. And you have a much smaller volume of fluid to contend with.

If you add 10Units to 1000cc, it works out to 1mU/min=6ml/hr. At 3am, my 6X table gets a little fuzzy in my head, so I worked to get the concentration changed.

Where, you ask, does the 6 come from? Let's see. 1mU/min=60mU/hr. 10Units in 1000cc=10,000mU/1000ml. Therefore, there are 10mU in 1ml and 1mU in 0.1ml. If you want 60mU/hr, you multiply 60X0.1=6ml/hr to get 1mU/min.

Many hospitals now have a special bag for the bolus of Mag Sulfate that only holds the bolus dose, so there's less chance of getting too large a dose of Mag. That way, Pharmacy does the calculations. If not, the usual concentration is 40Gm Mag in 1000cc. One of the most common loading doses is 4Gms. That would be in 100cc. How fast do you want to give it? If half an hour, you'd set the pump to give 200cc/hr, total volume to be infused 100cc. If you want it to run in in 20 min, you'd set it at a rate of 300cc/hr, total volume 100cc.

Hope I didn't confuse you. You'll get it. Good luck.