Setting Up IV Drug Infusions: A Quick Start Guide
D. John Doyle MD PhD
djdoyle@hotmail.com
April 2004
Intravenous infusions of medications are
commonly required in acute care medicine.
Examples include heparin and nitroglycerine
infusions in some patients with unstable
angina, morphine infusions for patients with
extreme pain or infusions of inotropes such
as dopamine or epinephrine to improve
cardiac performance.
Suppose, for instance, that you want to start
an infusion of dopamine to be infused through
a central line (one going directly into the right
heart). To set up a dopamine drip mix 200 mg
of concentrated dopamine in 250 ml of saline,
making an IV bag with a concentration of 800 mcg (micrograms) per ml. The rate you chose to run the infusion at will depend on clinical circumstances. For a "renal dose" dopamine drip, intended to boost renal performance, the dopamine infusion in the range of 2 to 4 mcg/kg/min is usually picked. A particular value of 3 mcg/kg/min is a reasonable midpoint, so we will use that.
The particular choice of ml/ hr corresponding to a particular choice of mcg/kg/min is an arithmetic exercise often done badly, but is still only basic algebra and will not be discussed here. (For the algebraically hopeless, here is a resource that will help you:
If you are still in a setting of complete arithmetic ignorance about how to dial in a particular choice of mcg/kg/min, consider the following practical clinical rule-of-thumb: Drug infusion design protocols for inotropes are ideally set up such that a rate of 15 ml / hr of drug mixture is providing a mild-to-moderate level of inotropy ( or a mild-to-moderate clinical effect for other classes of drugs). However, this unpublished guideline is often violated.
The resulting IV bag mixture is delivered by volumetric infusion pump. These generally require a special IV tubing set (that may contribute significantly to infusion setup cost.)
Here are some standard drug dilutions often used. More important, and not discussed here, is suggested drug infusion rates for various clinical circumstances; for that information the reader is directed to standard textbooks.
Drug Mixtures in Common Use
DRUG DOSE IV BAG VOLUME NOTE
Dopamine 200 mg 250 ml (NS or D5W) 800 mcg / ml [0.8 mg / ml]
Dobutamine 250 mg 250 ml (NS or D5W) 1 mg / ml [1000 mcg / ml ]
Epinephrine 1 mg 250 ml (NS or D5W) 4 mcg / ml [0.004 mg / ml]
Nitroglycerine 100 mg 250 ml Glass D5W 400 mcg/ml [0.4 mg/ml]
Morphine 100 mg 100 ml minibag 1 mg / ml
Heparin 25000 u 250 ml (NS or D5W) 100 units / ml
Insulin 100 u 500 ml D5W 5 ml / hr = 1 unit / hr
Sodium 50 mg 500 ml D5W 1 to 10 mcg/kg/min or less
Nitroprusside
