Dosage calculation question

There's the "book" and there's the "real world" answer. The book answer is 2.27 (or whatever is your school's policy on rounding). In the real world, you would administer 2.3 ml, because 2.27 would be impossible to draw up.

If the question specifically state "round to the nearest tenth, whole, etc" then I round. If it doesn't say to round, I don't round. In that question it doesn't say to round so I'd say 2.27 mL.

Thanks I was confused on that being the answer. I assumed since the volume was greater than 1 ml that it should have been rounded to the tenths position even though it is a pediatric patient

Your instructor should have provided you rounding criteria for use in her or his class. In the absence of such criteria, he or she should accept responses that will be employed in actual practice. As Klone wrote in her post, in actual practice the volume to be administered would be rounded to the nearest 0.1 mL, the gradation increment in most 3 mL syringes. In the problem you described, the difference in the dose administered, if you rounded to 2.3 mL is 2.49 mg.

If this were being administered IV, using a syringe pump you could use a syringe with 2.3 mL (191.67 mg) and program it to deliver the 188.9 mg (2.2668 mL) dose. As you are delivering this IM, this obviously isn't an option. This does, however highlight the more important consideration. As the maximum volume per injection site for newborns and young infants is 0.5 mL, you would have to deliver this dose in five separate injection sites. And your going to do this twice a day?

When I precept new nurses or nursing students I stress the importance of questioning their answer when it doesn't make sense. Giving an infant a dose of any medication that requires five separate injection sites should be questioned. When students are given problems where this is the "correct" response, they never learn to question answers that just don't seem right.

Just another example of an instructor writing a question that just doesn't make sense.

Your instructor should have provided you rounding criteria for use in her or his class. In the absence of such criteria, he or she should accept responses that will be employed in actual practice. As Klone wrote in her post, in actual practice the volume to be administered would be rounded to the nearest 0.1 mL, the gradation increment in most 3 mL syringes. In the problem you described, the difference in the dose administered, if you rounded to 2.3 mL is 2.49 mg.

If this were being administered IV, using a syringe pump you could use a syringe with 2.3 mL (191.67 mg) and program it to deliver the 188.9 mg (2.2668 mL) dose. As you are delivering this IM, this obviously isn't an option. This does, however highlight the more important consideration. As the maximum volume per injection site for newborns and young infants is 0.5 mL, you would have to deliver this dose in five separate injection sites. And your going to do this twice a day?

When I precept new nurses or nursing students I stress the importance of questioning their answer when it doesn't make sense. Giving an infant a dose of any medication that requires five separate injection sites should be questioned. When students are given problems where this is the "correct" response, they never learn to question answers that just don't seem right.

Just another example of an instructor writing a question that just doesn't make sense.

Yes, this. The patient weighs 3.778 kg so we can assume it is an infant. You cannot administer 2.3 mL IM to an infant in one injection. I've also never seen ampicillin ordered IM in 11 years of pediatric nursing.

In order to deliver 2.27 ml it would require you use two syringes It makes more sense to round the dose. I was taught round the dose according to the syringe in this case it would call for a 3ml syringe which has 0.1 ml marking so the dose would be round up to 2.3 ml

When performing my dosage calculations I do not round anything until the end. When I do round, I round according to the equipment i'm Using in this case it you would use a 3 ml syringe and round to the tenths position since a 3 ml syringe has 0.1 ml markings. I'm not sure why the answer was 2.27 ml. I guess they are expecting you to draw up that dose using multiple syringes