# Pediatric Dosage Calculation, and another one

Published

I'm in my last semester of school, and feel like all of a sudden I'm having a hard time with my calculations. I have spent so long trying to figure out these calculations! Can anyone offer me some insight or how to set these problems up?

Available: 180 mg morphine sulfate in 250 ml D5W

Patient weighs: 100 lbs

How many ml per hour should this patient receive?

and

2) Order: 200 mg of morphine (HIGH ALERT DRUG) are to be added to 250 ml of D5W. This solution is to be infused at a rate of 10 mg/hr.

How many ml/hr will the patient receive?

I feel like this problem is missing something...but I know it's probably me that's missing it haha!

38 Posts

well i figurd out #1 on my own.

100lb=45.45kg

0.005mg x 45.45kg = 0.227 mg

0.227 mg x 60 mins = 13.64 mg /hr

13.64 mg

180 mg x 250ml = 18.9 ml/hr

I also figured it out using dimensional analysis since that's the method my school uses, but it's too hard to type out fractions on here

392 Posts

Specializes in Cath Lab & Interventional Radiology. Has 7 years experience.

I would set #2 up like this:

200mg/250ml= X (x will be your mg/ml concentration)

10mg/X = Y (ml/hr)

1,229 Posts

Specializes in Labor and Delivery. Has 3 years experience.
I'm in my last semester of school, and feel like all of a sudden I'm having a hard time with my calculations. I have spent so long trying to figure out these calculations! Can anyone offer me some insight or how to set these problems up?

Available: 180 mg morphine sulfate in 250 ml D5W

Patient weighs: 100 lbs

How many ml per hour should this patient receive?

and

2) Order: 200 mg of morphine (HIGH ALERT DRUG) are to be added to 250 ml of D5W. This solution is to be infused at a rate of 10 mg/hr.

How many ml/hr will the patient receive?

I feel like this problem is missing something...but I know it's probably me that's missing it haha!

2. ml/hr= 250 ml/ 200 mg X 10mg/ 1 hr = 2500/200 = 12.5 ml/hr

4 Articles; 20,908 Posts

Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma. Has 43 years experience.
well i figurd out #1 on my own.

100lb=45.45kg

0.005mg x 45.45kg = 0.227 mg

0.227 mg x 60 mins = 13.64 mg /hr

13.64 mg

180 mg x 250ml = 18.9 ml/hr

I also figured it out using dimensional analysis since that's the method my school uses, but it's too hard to type out fractions on here

Look at the second calculation and question carefully...your Morphine bag concentration changed.

1) 180 mg morphine sulfate in 250 ml D5W

2) 200 mg of morphine (HIGH ALERT DRUG) are to be added to 250 ml of D5W.

• ## Care Plans Guide

Create well-written care plans that meets your patient's health goals.