Dose Calculations Flashcards
How do you calculate w/v doses?
w/v expresses the number of grams in 100ml
Work out the number of grams per ml by dividing w/v by 100
Work out the dose required for the animal in question, ensuring that the units are the same as those for the w/v
dose/(g/ml) = ml requirement
How do you convert g to mg
1000mg in a gram
8g=8000mg
x g by 1000 to get mg and / mg by 1000 to get g
How do you convert ug to mg and g
1g = 1,000,000ug
What does gtt/ml stand for ?
drips per ml (fluid sets)
What increases or decreases the rate at which drips fall into the chamber?
Roller clamp
How do you work out IV fluid rates?
Work out total fluid required over period of time by multiplying ml/kg by patients weight
Work out the number of drips are required to administer the total fluid amount by multiplying ml by gtt/ml
Divide the gtt by the total time in hrs to get the drips per hour
Divide this number by 60 to work out gtt/min
How would you make a 10 ml 1:10,000 preparation from a 1:1000 solution
Initial solution
1g:1000ml = 0.001g/ml
Final solution is 1:10,000 or 0.0001g/ml (x 10ml) 0.001g in 10ml
0.001/0.001= 1 (1ml of original solution and 9ml of solvent)
• Lidocaine 2% is used as an intravenous drip at 2 mg/min. How much 2% lidocaine is required to make up 500 ml of fluid at a concentration of 2 mg/ml
Initial solution = 2g/100ml = 2000mg/100ml = 20mg/ml
Target solution = 500ml x 2mg/ml = 1000mg total
1000/20 = 50ml initial solution and 450 ml
• You need to administer this lidocaine (2mg/ml) at an infusion rate of 50 µg/kg per min to 10 kg dog. How many drops/minute should you set a 60-drop set (60 gtt/ml)?
Work out drug requirement per min for the patients weight
50x10=500ug= 0.5mg per min
Work out how many mls is required to supply this dose
0.5/2 = 0.25ml per min
Work out how many drops required to administer this.
60 x0.25 = 15drops per min
How many cm are in a ft
30cm
