Monday, January 4, 2016

Dosage Calculation - Volume/Time - IV Drop Rate Questions

Source Website: http://www.dosagehelp.com/iv_rate_drop.html
By DosageHelp.com


Volume/Time - IV Drop Rate Questions

Given a certain amount of liquid, a time period, and a drop factor (gtts/mL), what is the necessary IV flow rate in gtts/min? Measurement used when IV is regulated manually. Because it is not possible to give a patient a fraction of a drop, it is typical to round answers for these problems up or down to the nearest whole number. 

Formula:


     
         
            
              Volume (mL)
              Time (min)
           
           x
           Drop Factor (gtts/mL)
           =
           Y(Flow Rate in gtts/min)
        
     

Example: Calculate the IV flow rate for 1200 mL of NS to be infused in 6 hours. The infusion set is calibrated for a drop factor of 15 gtts/mL.

         
            
              Volume (mL)
              Time (min)
           
           x
           Drop Factor (gtts/mL)
           =
           Y(Flow Rate in gtts/min)
        
Convert 6 hours to minutes.
    min ← hr    ( x by 60 )
    6 hr x 60 = 360 min


         
            
              1200 mL
              360 min
           
           x
           15 gtts/mL
           =
           
             50 gtts/min
          
        

Example: Calculate the IV flow rate for 200 mL of 0.9% NaCl IV over 120 minutes. Infusion set has drop factor of 20 gtts/mL.

         
            
              Volume (mL)
              Time (min)
           
           x
           Drop Factor (gtts/mL)
           =
           Y(Flow Rate in gtts/min)
        

         
            
              200 mL
              120 min
           
           x
           20 gtts/mL
           =
           
             33 gtts/min
          
        

Question (16): (From Ngee Ann Polytechnics Dosage Calculation Worksheet)
ORDER: I/V Normal Saline 1000 mL over 24 hours. Drop Factor = 60 gtts/mL.


         
           Rate:
           
             
          
          gtts/min
        

         
            
              Volume (mL)
              Time (min)
           
           x
           Drop Factor (gtts/mL)
           =
           Y(Flow Rate in gtts/min)
        
Convert 24 hours to minutes.
    min ← hr    ( x by 60 )
    24 hr x 60 = 1440 min


         
            
              1000 mL
              1440 min
           
           x
           60 gtts/mL
           =
           
             41.7 gtts/min
          
        
Answer rounded to the nearest whole number = 42 gtts/min

Question (18): (From Ngee Ann Polytechnics Dosage Calculation Worksheet)
I/V D5% 1000 mL over 8 hours. Drop Factor = 20 gtts/mL.

         
           Rate:
           
             
          
          gtts/min
        

         
            
              Volume (mL)
              Time (min)
           
           x
           Drop Factor (gtts/mL)
           =
           Y(Flow Rate in gtts/min)
        
Convert 8 hours to minutes.
    min ← hr    ( x by 60 )
    8 hr x 60 = 480 min


         
            
              1000 mL
              480 min
           
           x
           20 gtts/mL
           =
           
             41.7 gtts/min
          
        
Answer rounded to the nearest whole number = 42 gtts/min

Question (19): (From Ngee Ann Polytechnics Dosage Calculation Worksheet)
ORDER: I/V gentamycin 80 mg/100 mL N/Saline over 1 hour. Drop Factor = 60 gtts/mL.


         
           Calculate Rate:
           
             
          
          gtts/min
        

         
            
              Volume (mL)
              Time (min)
           
           x
           Drop Factor (gtts/mL)
           =
           Y(Flow Rate in gtts/min)
        
Convert 1 hours to minutes.
    min ← hr    ( x by 60 )
    1 hr x 60 = 60 min


         
            
              100 mL
              60 min
           
           x
           60 gtts/mL
           =
           
             100 gtts/min
          
        

Question (20): (From Ngee Ann Polytechnics Dosage Calculation Worksheet)
ORDER: I/V Osmofundin 20% 100 mL over 30 Minutes. Drop Factor 60 gtts/mL.


         
           Rate:
           
             
          
          gtts/min
        

         
            
              Volume (mL)
              Time (min)
           
           x
           Drop Factor (gtts/mL)
           =
           Y(Flow Rate in gtts/min)
        

         
            
              100 mL
              30 min
           
           x
           60 gtts/mL
           =
           
             200 gtts/min
          
        

Continue (Go to Volume/Time - IV mL Rate Questions)




Reference 
[1] Advanced Formatting, Ry’s MathML Tutorial, http://rypress.com/tutorials/mathml/advanced-formatting.
[2] MathML, Presentation MathML, https://en.wikipedia.org/wiki/MathML.
[3] MathJax in Blogger (II), Posted on Tuesday, 12 July 2011, http://irrep.blogspot.sg/2011/07/mathjax-in-blogger-ii.html
[4] MathJax, http://docs.mathjax.org/en/latest/start.html

[5] MathML Fundamentals (Colours), W3C recommendation, http://www.w3.org/TR/MathML/chapter2.html