Monday, June 1, 2009

Calculating IV flow rates

Intravenous fluid must be given at a specific rate, neither too fast nor too slow. The specific rate may be measured as milliliter per hour (ml/hr) or drops per minute (gtt/min).

The formula used are:
1. if there is no drip factor given, the question will always ask for ml/hr or flow rate ***ml/hr = volume given / hours***
Sample problem:
An order was written to infuse a liter of IV fluid every 8 hours, at what rate would the IV pump be set for?
>>> Solution <<<
ml/hr = 1000ml/8hrs = 125 ml/hr

2. If drip factor is given, the answer will always be gtt/min
***gtt/min = volume x drop factor / hours x 60***

Sample problem:
1500 ml IV Saline is ordered over 12 hours. Using a drop factor of 15 drops/ml, how many drops per minute need to be delivered?
>>> Solution <<<
gtt/min = 15gtt/1ml x 1500ml/12 hrs x 1 hr/60min = 31.25gtt/min

Sample 3
MD ordered 100ml of NaCl to be infused over 30 minutes with a drip factor of 16gtt/ml
gtt/min = 16gtt/1ml x 100ml/30min = 53.33

click below for sample problems

1. Order: D5W 1000ml q6 hours IV. What is the flow rate of there is an infusion pump?

2. Order: LR 1000ml over 12 hours using an infusion pump. What is the flow rate?

3. Order: Infuse 10% lipids 500 ml over 10 hours. What is the flow rate?

4. Order: Verapamil 1mg/hr IV. Available: Verapamil 10mg in 100ml D5W. What is the infusion rate?

5. Order: Dopamine 7mcg/kg/min. Available: Dopamine 400mg in 250 ml D5W. Patient weight is 125.4lbs. What is the infusion rate?

will type gtt/min problems later...