Dosage Calculations

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I am in a desperate situation. I thought I was getting my calculations correctly and today I got back my math results and i got a 70% I am so disappointed I dont know what to do. On my first exam I received an 80%.

My professor said that if i get above 95% on my final (which is next week) I may be able to average a b+ or a- , but it will all depend on the overall average, if he curves grades or not. I went and bought 2 self help books on calculations .... My question is ..... do you think it is humanly possible to ingest all this info by next week (exactly a week from today)! I am having problems with the drips and the three step conversions. Is there a website that can help me? To top it off my professor sucks, so what I have learned, I have learned on my own. I am so frustrated, so much so, that it is getting harder and harder for me to pick up a book .....sorry for venting

Specializes in med/surg, telemetry, IV therapy, mgmt.
cperg51018 said:
1. A Physician orders an IV of D5W to run at 100 mL (per 60 minutes?). The drop factor of the IV tubing is 10 gtts/mL. What is the flow rate?

100 mL/60 minutes (amount to give) x 10 gtts/1 mL (drop factor of IV tubing) = 16.66 gtts/minute, rounded off to 17 gtts/minute (a drop must be a whole number)

cperg51018 said:
2. Tetracycline is prepared in 50 mL of an IV solution. It is infusing at 30 gtts/minute. The drop factor of the infusion set is 20 gtts/mL. What is the infusion time?

1 minute/30 gtts (infusion rate) x 50 mL/1 (amount to give) x 20 gtts/1 mL (drop factor of IV tubing) = 33.33 minutes

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Thank you for your help in the calculation if medication through IV, I am studying to be a CMA certified medical assistant and I am in phlebotomy now and we are into the calcultaions, Is there any way of breaking these calculations down to help understand them better?

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Specializes in med/surg, telemetry, IV therapy, mgmt.

Do many problems. read the problem carefully and pick out the terms that are in this formula: dose desired divided by dose on handed multiplied by the amount the dose on hand is in equals the amount to give. make sure you read the final line of the problem and you understand exactly what the problem is asking you to find. for iv problems you may need to factor in the drops/ml of the iv tubing to get the rate/hour. apply conversion factors as needed.

There are medication calculation tutorials on post #3 of this thread:

And you can see lots of problems that have been worked out on this thread if you go back through the posts.

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Someone please help!!!

I am currently taking dosage. I have been having a hard time with these questions trying to figure out the formulas but dont seem to understand how to do them. If anyone could help that would be great. I will post a few at the bottom please let me know.

A nipride drip is ordered to infuse on a pump at 2mcg/kg/min on a patient weighting 110lbs. Nipride is supplied 50mg/250ml d5w. How many ml/h will the iv need to run?

A dopamine drip is ordered to infuse at 3mcg/kg/min. The solution is avaliable in 400mg in 250ml d5w. The patient weights 155lbs. Using a 60gtt/ml set:

what is the mcg/min dosage?

What is the gtt/min flow rate?

An order of 250mg in 5ml is to be diluted to a total of 50ml and given over 70min. How much dilutent should be used? And what is the ml/hr rate?

I appreciate any feedback that i get. Thanks

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Specializes in med/surg, telemetry, IV therapy, mgmt.
pycho24 said:
a nipride drip is ordered to infuse on a pump at 2mcg/kg/min on a patient weighting 110lbs. nipride is supplied 50mg/250ml d5w. how many ml/h will the iv need to run?
2 mcg/1 kg
(dose desired)
x 110 pounds/ 1 minute
(patients weight/time dose desired to infuse)
x 250 ml/50 mg
(dose on hand)
x 1 kg/2.2 pounds
(conversion factor)
x 60 minutes/1 hour
(conversion factor)
x 1 mg/1000 mcg
(conversion factor)
=
30 ml/hour
(amount to give)
pycho24 said:
a dopamine drip is ordered to infuse at 3mcg/kg/min. the solution is available in 400mg in 250ml d5w. the patient weights 155lbs. using a 60gtt/ml set:

what is the mcg/min dosage?

what is the gtt/min flow rate?

3 mcg/1 kg
(dose desired)
x 155 pounds/ 1 minute
(patients weight/time dose desired to infuse)
x 1 kg/2.2 pounds
(conversion factor)
=
211.36363 mcg/min, rounded off to
211 mcg/min
(amount to give)
211 mcg/1 minute
(dose desired)
x 250 ml/400 mg
(dose on hand)
x 60 gtts/1 ml
(drip factor of iv tubing)
x 1 mg/1000 mcg
(conversion factor) = 7.9125 drops/minute, rounded off to
8 gtts/minute
(flow rate)
pycho24 said:
an order of 250mg in 5ml is to be diluted to a total of 50ml and given over 70min. how much diluent should be used? and what is the ml/hr rate?
50 ml - 5 ml =
45 ml
(amount of diluent to use)
50 ml/70 minutes
(dose to give)
x 60 minutes/1 hour
(conversion factor) = 42.857142 ml/hour, rounded off to
43 ml/hour
(infusion rate)
1
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Hey can i ask for your help on two more?

The order is to infuse 500mg in 250ml at a rate of 8ml/h. Calculate the mg/h? And what are the mcg/min being recieved?

A heparin drip was ordered to infuse at 1250units/h. The solution strength is 20,000units in 500ml d5w. A pump is used to monitor the rate. Calculate the flow.

Thanks

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Specializes in med/surg, telemetry, IV therapy, mgmt.
pycho24 said:
the order is to infuse 500 mg in 250 ml at a rate of 8 ml/hour. calculate the mg/hour. what are the mcg/minute being received?
this is similar to the last problem you asked about. . .
500 mg/250 ml
(dose on hand)
x 8 ml/hour
(infusion rate)
=
16 mg/hour
(dose being given)
16 mg/hour x 1000 mcg/1 mg
(conversion factor)
x 1 hour/60 minutes
(conversion factor) = 266.666 mcg/minute, rounded off to
267 mcg/minute
pycho24 said:
a heparin drip was ordered to infuse at 1250 units/hour. the solution strength is 20,000 units in 500 ml of d5w. a pump is used to monitor the rate. calculate the flow.
pumps are always set at
mls per hour
1,250 units/hour
(dose desired)
x 500 ml/20,000 units
(dose on hand) = 31.25 ml/hour which must be rounded off to
31 ml/hour
(rate to set the iv pump at)
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I would really appreciate some help with these problems. I am in the nursing program and am having a hard time with dosage. I just dont understand how to set the problem up? How do you know which formula to use for each question? If anyone has any advice for me ill take that as well thanks

1) your patient has heparin 25,000units in 1l d5w infusing at 15gtt/min. Using a 20gtt/ml set calculate the u/h of heparin?

2) ordered 500ml d51/2 ns iv q8h. Using tubing calculated at 20gtt/ml what is the gtt/min?

3) pitocin was ordered 2 milliunits/min iv. The solution is 9 units in 150 ml ns. What is the pump setting?

4) a doctor orders 500ml d5w with 0.5g aminophylline to infuse at 50ml/h. How many mg will the patient recieve each hour?

5) a child weighting 21.4kg has an order for 500mg of a medication in 100ml d5w q12h. The normal daily dosage range is 40-50mg/kg/day. Determine if the dose is within normal range and show your work?

6) pitocin is supplied 15units/250ml ns. The order is foe 5milliunits/min to be infused by pump. How many ml/h will the patient recieve?

7) the physician orders heparin 1500units/h iv. The pharmacy sends heparin 25,000units in 250ml of d5w. Calculate the pump setting in ml/h?

? a client who weights 22lbs has an iv of 800mg dopamine in 250ml of ns infusing at 42 gtt/min. The drop factor is 60gtt/ml. How many mcg/kg/min is he recieving? And how many ml/h is the patient recieving?

9) a child weighting 12.6 kg was ordered tylenol 15mg/kg for fever over 102.0 the child at 1100 had a temp of 104.2 tylenol is supplied 120mg/5ml how much tylenol in ml should be given?

10)the order reads 2000ml of d5.9% naci over 24h. The iv set delivers 10gtt/ml. What rate in gtt/min will you set the iv to run?

11) bicillan cr is ordered 1.2million units of im. It comes 600,000 units in 1 ml. How many ml of bicillian cr should be given?

12) nipride is ordered to infuse 0.8mcg/kg/min. The drip comes from pharmacy with 100mg nipride in 500ml of ns. What is the rate that the pump should be set for a patient weighting 66kg?

I appreciate all of your help in advance!! Thanks a million! Thanks again

1
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Have a good day!!!!

1
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Specializes in OR, ICU, Home Health.

If anyone would be willing to help me with the following problem would be greatly appreciated.

Calculate the creatinine clearance for a 70 year old who weights 150 lbs and has a serum creatinine of 2.5mg/dl using the following formula: ClCr (male) in ml/min=lean body weight (kg) x (140 - age in years) / serum creatinine x 72.

A. Clarithromycin (Biaxin) is an antibiotic which requires a reduced dosage if the creatinine clearance is below 30 ml/min.

B. Suppose the patient were a 60 year old male instead of a 70 yr old.

C. Suppose the patient were a 60 year old woman. The formula changes to ClCr (female) in ml/min=lean body weight (kg) x (140 - age in years) (0.85) / serum creatinine x 72.

Thank you

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Specializes in OR, ICU, Home Health.

Please disregard my previous message, I figured it out today, just too tired I guess last night and my brain was not working.

Thanks:yeah:

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I am having trouble with this question and I would appreciate the help.

Ordered: Digoxin 0.005 mg po BID

Available: Digoxin 0.05mg/ml

recommended dose 0.02mg/kg/24hr

childs weight is 35lbs.

What is the recommended BID dose? The answer says 0.16. But I dont know how to work the problem out please help

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