Yo. Hope everyone's studying is going well. I have a few practice questions I found off of a website, and it's good practice. I didn't write 'em, so please don't bite my head off if you see something wrong. I was looking for practice case scenarios, so if I find any and have time I'll put those up too.
5. Your order is for meperidine (Demerol) 35 mg, IM, STAT. Available is a 2-mL vial containing 50 mg/mL meperidine. On hand are 1 cc and 3 cc syringes. How much should you draw up into which syringe?
13. You have an order to infuse 1000 mL of D5W (5% Dextrose in water) IV over a period of 5 hr. No pump is available, but the tubing set package notes that the drop factor is 10 gtt/mL. How would you adjust the drip rate?
14. The order is for meperidine 60 mg and atropine gr 1/150, IM. The meperidine on hand is 100 mg/mL and the atropine is 0.4 mg/mL. The two are compatible so you plan to draw up both in the same syringe. How much of each will you draw up?
15. Tagamet is ordered 200 mg, IV, q6h. Available is Tagamet 300 mg in a 2 mL vial of aqueous solution. You are to dilute a portion of this in 100 mL NS and infuse over 20 minutes using a Buretrol with a drop factor of 60 gtt/mL. How much Tagamet will you inject into the Buretrol, and what will the drip rate be?
16. The order is for amoxicillin 60 mg, po, tid for a child weighing 13 lb. The pediatric dosage range is 20-40 mg/kg/day in three equal doses. Is the dose safe?
17. A child with severe poison ivy weighs 25 kg and Benadryl po 5 mg/kg/day is ordered q6h. Benadryl is available as a 12.5 mg/5 mL solution. What dose should be given?
19. Your patient weighs 143 lb, and you are ordered to infuse 250 mg dobutamine in 500 mL NS at 10 mcg/kg/min. How many milligrams of dobutamine will infuse per hour?
20. Phenobarbital 180 mg/m2/24 hours given every eight hours is ordered for a child whose BSA (body surface area) is 0.29 m2. How much will each dose be?
21. You are to give Lidocaine 30 mcg/kg/min to a child weighing 55 lb. The piggyback contains 120 mg Lidocaine in 100 mL NS. At hat rate will you set the pump?
ANSWERS:
5. Your order is for meperidine (Demerol) 35 mg, IM, STAT. Available is a 2 mL vial containing 50 mg/mL meperidine. On hand are 1 cc and 3 cc syringes. How much should you draw up into which syringe?
Your answer will be in mL (cc), the number of milliliters that will contain 35 mg meperidine. You know from the label that there is 50 mg meperidine in 1 mL of meperidine solution. You realize you will give less than 1 mL. Your set up:
35 mg mep. x 1 mL mep. sol = 0.7 mL mep. sol
50 mg mep.
or, since you know that you want "mL on top" in your answer, you could start with 1 mL/50 mg:
1 mL x 35 mg = 0.7 mL
50 mg
If you don't actually write down full labels, at least be thinking "mL of what?" "mg of what?"
13. You have an order to infuse 1000 mL of D5W (5% Dextrose in water) IV over a period of 5 hr. No pump is available, but the tubing set package notes that the drop factor is 10 gtt/mL. How would you adjust the drip rate?
First, what do you want to know? The flow rate in gtt/min, which are the answer units. What do you know? You're given that there are 10 gtt/mL and that the infusion rate is 1000 mL/5 hr. Since you want gtt on top and 10 gtt/mL has gtt in the right place, 10 gtt/mL makes a perfectly good starting factor--from there you just need to get from mL to min. The set up then:
10 gtt x 1000 mL x 1 hr = 33 gtt
1 mL 5 hr 60 min min
You wouldn't want to count a full minute, so divide by 3 and count for 20 seconds.
14. The order is for meperidine 60 mg and atropine gr 1/150, IM. The meperidine on hand is 100 mg/mL and the atropine is 0.4 mg/mL. The two are compatible so you plan to draw up both in the same syringe. How much of each will you draw up?
For both you want to know mL, your answer unit.
60 mg x 1 mL = 0.6 mL meperidine
100 mg
1 gr x 64.8 mg x 1 mL = 1.1 mL atropine
150 1 gr 0.4 mg
15. Tagamet is ordered 200 mg, IV, q6h. Available is Tagamet 300 mg in a 2 mL vial of aqueous solution. You are to dilute a portion of this in 100 mL NS and infuse over 20 minutes using a Buretrol with a drop factor of 60 gtt/mL. How much Tagamet will you inject into the Buretrol, and what will the drip rate be?
You want to know mg of Tagamet, and gtt/min.
200 mg T. x 2 mL T. sol = 1.3 mL T.
100 mL NS 300 mg T. 100 mL NS
The drip rate would be:
60 gtt x 101.3 mL T. sol = 304 gtt T. sol
1 mL 20 min min
Can you count 5 gtt/sec? Not likely, so what do you do? What if you added a secondary set with a drop factor of 12 gtt/mL?
12 gtt x 101.3 mL T. sol = 60 gtt T. sol
1 mL 20 min min
16. The order is for amoxicillin 60 mg, po, tid for a child weighing 13 lb. The pediatric dosage range is 20-40 mg/kg/day in three equal doses. Is the dose safe?
You want to know mg/kg/day for this child. What you know is that you will give 60 mg per 13 lb body weight per dose or 60 mg/13 lb/dose, which true but is unusable in this form, so you rewrite it as 60 mg/13 lb x 1 dose. How can you do that? Consider dividing 1/4 by 2. Half of one quarter is one eighth, but how to figure that:
1 = 1 x 1 = 1 = 1
4 4 2 4 x 2 8
2
Dividing by 2 is the same as inverting 2 to get 1/2 and multiplying. Acceleration, to give another example, is measured in feet per second per second or ft/sec/sec, which is equal to ft/sec x sec or ft/sec2.
60 mg x 2.2 lb x 3 dose = 30.5 mg = 30.5 mg/kg/day--a safe dose.
13 lb x 1 dose 1 kg 1 day kg x day
Whenever you have x per y per z, rearrange in the form x/y*z and everything will stay straight.
17. A child with severe poison ivy weighs 25 kg and Benadryl po 5 mg/kg/day is ordered q6h. Benadryl is available as a 12.5 mg/5 mL solution. What dose should be given?
You want to know mL/dose. Since you want mL on top, start with:
5 mL x 5 mg x 1 day x 25 kg = 12.5 mL
12.5 mg kg x day 4 doses dose
19. Your patient weighs 143 lb, and you are ordered to infuse 250 mg dobutamine in 500 mL NS at 10 mcg/kg/min. How many milligrams of dobutamine will infuse per hour?
You want to know mg/hr, which has time on the bottom. After converting to 10 mcg/kg x min you note that time is also on the bottom, so this should work as a starting factor:
10 mcg x 60 min x 1 mg x 1 kg x 143 lb = 39 mg
kg x min 1 hr 1000 mcg 2.2 lb hr
20. Phenobarbital 180 mg/m2/24 hours given every eight hours is ordered for a child whose BSA (body surface area) is 0.29 m2. How much will each dose be?
You want to know mg/dose, so you could start with 1 day/3 doses or 180 mg/m2/day:
1 day x 180 mg x 0.29 m2 = 17.4 mg
3 doses m2 x day dose
21. You are to give Lidocaine 30 mcg/kg/min to a child weighing 55 lb. The piggyback contains 120 mg Lidocaine in 100 mL NS. At what rate will you set the pump?
You want to know mL/hr. Starting with the patient's weight usually works out:
55 lb x 1 kg x 30 mcg x 1 mg x 100 mL x 60 min = 37.5 mL
2.2 lb kg x min 1000 mcg 120 mg 1 hr 
