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The doctor ordered Vancomycin 10mg/kg IVPB every 8 hours for infection. The patient's

weighs 20 lbs. The nursing drug reference states: dilute each 500 mg vial with 10 mL of sterile water for injection and further dilute in 100 mL of NS to infuse over 1 hour.

48. How many milliliters will you draw from the vial after reconstitution?

Answer 1.8 mL

49. Calculate the milliliters per hour to set the IV pump.

Answer 100 mL/hr

50. Calculate the drops per minute with a drop factor of 10 gtt/mL

Answer 16 -17 gtts

51. The doctor ordered one unit of PRBC to infuse in 3 hours. The unit of blood is

labeled 275 ml. At what flow rate will you set the IV pump?

Answer 91 -92 mL/hr

I am studying for my dosage calc test , I came across this problem and I have no idea where to begin. I'm not looking for answers just an explanation as to why these answers are correct and how to reach these answers on my own . Please help me!!

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Specializes in Complex pedi to LTC/SA & now a manager.

How do you set up any of the dosage calculation problems that you have worked before? What information do you know? What information are you trying to figure out? Are all your units correct or do you need to convert (eg need Xmg/kg/day and weight is in lbs so need to convert lbs to kg)? Start there...

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First I would convert 20lbs to kg which is 9.09 kg. so 10mg/kg would be 91 mg every 8 hours . That's about as far as I can get . I'm totally lost .

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Ok so I came up with this . 90mg/500mg x 10ml= 1.8 mL. Is this correct ?

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

Yes that is correct. So if you add 1.8ml to 100ml 0.9ns what do you set the pump at to deliver 100mls over 1 hour.

[TABLE=class: fraction]

[TR]

[TD=class: numerator]Volume (mL) = Y (Flow Rate in mL/hr)

[/TD]

[/TR]

[TR]

[TD=class: denominator] Time (hr) [/TD]

[/TR]

[/TABLE]

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

[TABLE=class: formula]

[TR]

[TD][TABLE=class: fraction]

[TR]

[TD=class: numerator]Volume (mL)

[/TD]

[/TR]

[TR]

[TD=class: denominator] Time (min) [/TD]

[/TR]

[/TABLE]

[/TD]

[TD] x Drop Factor (gtts/mL) = Y (Flow Rate in gtts/min)

[/TD]

[/TR]

[/TABLE]

So for how many gtts using 10 gtt tubing.

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

The last one uses the same formula

Volume (mL) = Y (Flow Rate in mL/hr)

Time (hr)

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

Great site.....DosageHelp.com - Helping Nursing Students Learn Dosage Calculations

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Ok for the gtts I got 100ml/60 min x10gtts = 16.66 so 17 gtts

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I'm still confused on how to get mL/hr.

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I'm still confused on how to get mL/hr.

Go back a step and don't drop your unit labels. If you keep your labels on, you should be able to see which steps still need to be done to get what you need.

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Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

There are many way to got the answer. If you have 275mls to go equally over 3 hours. Divide 275 by 3.

Volume (mL) = Y (Flow Rate in mL/hr)

Time (hr)

or use the same formula.

[TABLE=class: cms_table_fraction]

[TR]

[TD=class: cms_table_numerator]Volume (mL) x Drop Factor (gtts/mL) = Y (Flow Rate in gtts/min)

[/TD]

[/TR]

[TR]

[TD=class: cms_table_denominator] Time (min)[/TD]

[/TR]

[/TABLE]

First how many min is in 3 hours ....

60min x 3hr =____min

1hr ?min

then use this formula. Your drop factor for this is under stood micro drop tubing or 60gtt/ml

[TABLE=class: cms_table_fraction]

[TR]

[TD=class: cms_table_numerator]Volume (mL) x Drop Factor (gtts/mL) = Y (Flow Rate in gtts/min)

[/TD]

[/TR]

[TR]

[TD=class: cms_table_denominator] Time (min)[/TD]

[/TR]

[/TABLE]

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