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Math Question

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by Brekka Brekka, ADN, RN (Member) Member

Brekka has 6 years experience as a ADN, RN and specializes in Geriatrics.

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Ok, so we're preparing for a math exam next week, and we seem to be having a problem with a question. Even the instructors are disagreeing on the answer, and we've gotten at least 3 different answers. So if you get the answer, how did you get it?We have been sitting in class for over an hour over this question:

"The doctor orders Nitroglycerin drip 50 mg in 250ml D5W to be given at 20 mcg per minute. What rate will you set the IV pump?"

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Nurse Kyles has 7 years experience as a BSN, RN and specializes in Cath Lab & Interventional Radiology.

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"The doctor orders Nitroglycerin drip 50 mg in 250ml D5W to be given at 20 mcg per minute. What rate will you set the IV pump?"

Convert milligrams to micrograms. 50mg x 1000 = 50,000mcg/250 ml = 200mcg/ml

Order: 20mcg x 60 minutes = 1200 mcg

1200 (mcg per hour)/ 200 (mcg per ml) = 60 ml per hour

Answer: 60 Ml/HR

Hope this helps!

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staphylococci has 7 years experience as a NP and specializes in Family Medicine and Pediatrics.

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Order: 20 mcg/min

On Hand: 50 mg Nitroglycerin/250 mL D5W

Infusion Rate: ? mL/hr

250 mL/50 mg x 1 mg/1000 mcg x 20 mcg/1 min x 60 min/1 hr = 6 mL/hr.

Edited by asystole00

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Nurse Kyles has 7 years experience as a BSN, RN and specializes in Cath Lab & Interventional Radiology.

391 Posts; 8,353 Profile Views

"the doctor orders nitroglycerin drip 50 mg in 250ml d5w to be given at 20 mcg per minute. what rate will you set the iv pump?"

convert milligrams to micrograms. 50mg x 1000 = 50,000mcg/250 ml = 200mcg/ml

order: 20mcg x 60 minutes = 1200 mcg

1200 (mcg per hour)/ 200 (mcg per ml) = 60 ml per hour

answer: 60 ml/hr

hope this helps!

oh my!! stupid math!! 1200/200= 6ml/hr

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Lol the general consensus for the class was 6mL/hr, 60mL/hr, or 41.7mL/hr.

They agreed the question was written badly and ended up revamping that question

I have never seen people get such heated tempers over a math question.

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ckh23 has 6 years experience as a BSN, RN and specializes in ER/ICU/STICU.

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Lol the general consensus for the class was 6mL/hr, 60mL/hr, or 41.7mL/hr.

They agreed the question was written badly and ended up revamping that question

I have never seen people get such heated tempers over a math question.

I don't see how it is a badly written question, seems like a pretty straight forward math question. As an FYI remember if you have your standard nitro concentration 50mg/250ml every 10mcg/min is 3 ml/hr so 20 mcg/min is 6ml/hr, 30mcg/min is 9ml/hr etc.

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BabyLady is a BSN, RN and specializes in NICU, Post-partum.

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"The doctor orders Nitroglycerin drip 50 mg in 250ml D5W to be given at 20 mcg per minute. What rate will you set the IV pump?"

Convert milligrams to micrograms. 50mg x 1000 = 50,000mcg/250 ml = 200mcg/ml

Order: 20mcg x 60 minutes = 1200 mcg

1200 (mcg per hour)/ 200 (mcg per ml) = 60 ml per hour

Answer: 60 Ml/HR

Hope this helps!

I agree 190% that this is the answer and it is accurate.

The question is not difficult, it is well-written and is very typical what you will encounter. I cannot believe the instructors did not know how to answer it...which is a little scary. It is a typical NCLEX math question.

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2 Posts; 430 Profile Views

1200 (mcg per hour)/ 200 (mcg per ml) = 60 ml per hour

Answer: 60 Ml/HR

I agree 190% that this is the answer and it is accurate.

The question is not difficult, it is well-written and is very typical what you will encounter. I cannot believe the instructors did not know how to answer it...which is a little scary. It is a typical NCLEX math question.

Except 1200 / 200 is 6ml/hr not 60ml/hr

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bols27 specializes in Hopefully ICU one of these days..

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is this a premixed bag of 50mg/250ml nitro to D5W? if not then you need to know either how many ml of nitro you have that equal 50mg or the mgs/ml of the nitro preparation you are mixing into the bag. For instance, if the nitro is 5mg/ml added to 250ml D5W then you will end up with a 260 ml bag therefore you will need to set a rate of 6.24....if it is a premixed bag then the rate will be 6. I would assume the idea was that the bag was already mixed since this is a common premix ratio. I agree that the question was poorly worded.

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ckh23 has 6 years experience as a BSN, RN and specializes in ER/ICU/STICU.

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is this a premixed bag of 50mg/250ml nitro to D5W? if not then you need to know either how many ml of nitro you have that equal 50mg or the mgs/ml of the nitro preparation you are mixing into the bag. For instance, if the nitro is 5mg/ml added to 250ml D5W then you will end up with a 260 ml bag therefore you will need to set a rate of 6.24....if it is a premixed bag then the rate will be 6. I would assume the idea was that the bag was already mixed since this is a common premix ratio. I agree that the question was poorly worded.

The OP states that the question gives the concentration of 50mg/250ml. A simple calculation question.

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