Transcript Intravenous infusions, Parenteral admixtures, and rate of flow

Intravenous infusions, Parenteral admixtures,
and rate of flow calculations
Dr. Osama A. A. Ahmed
Intravenous infusions, Parenteral admixtures, and rate of
flow calculations
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Intravenous (IV) infusions are sterile, aqueous preparations administered
intravenously in relatively large volumes.
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They are used to extend blood volume and /or provide electryltes, nutrients or
medications.
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Pharmacists participate in the preparation and administration of institutional as well as
home IV infusion therapy
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Commercially available infusions are prepared in glass or plastic bottles or collapsible
plastic ‘bags’ in volumes of 50 ml (a minibag), 100 ml, 250 ml, 500 ml, and 1000 ml.
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When a smaller IV bag is attached to the tubing of a larger IV being administered, it is
referred to as an IV piggyback (IVPB).
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Additional components or additives frequently are added to the basic IV solutions.
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Administration set used to deliver the fluid from IV bottle or bag to patient’s vein.
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The sets may be standard (macrodrip) or pediatric (microdrip).
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The passage of solution into patient’s vein may be assisted by gravity, or by electronic
volumetric infusion pumps. Some infusions pumps can be calibrated to deliver microinfusion volumes, such as 0.1 ml/hour to as much as 2000 ml/hour
Dr. Osama A. A. Ahmed
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Intravenous infusions, Parenteral admixtures, and
rate of flow calculations
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Example: How many grams each of dextrose and sodium chloride are used to prepare
a 250 ml bag of D51/2NS for IV infusion?
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250 X 0.05 (5% w/v) = 12.5 g dextrose
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250 X 0.0045 (0.45% w/v) = 1.125 g sodium chloride
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IV push (IVP, IV Stat, or sometimes as a bolus dose)
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The rapid injection of IV medications, as in emergency or critical care situations
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IV push medications frequently are administered in less than one minute, that depends
on precise calculations of dose and rate of administration.
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Example: a physician orders enalaprilat (VASOTEC IV) 2 mg IVP for a hypertensive
patient. A pharmacist delivers several 1- ml injections, each containing 1.25 mg of
enalaprilat. How many milliliters of the injection should be administered?
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1.25 mg
1ml
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2 mg
X ml
Dr. Osama A. A. Ahmed
X = 1.6 ml
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Intravenous infusions, Parenteral admixtures, and rate of
flow calculations
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Example: Calculate the daily infusion volume of D10W to be administered to a
neonate weighing 3 lb 8oz.on the basis of 60 ml/kg/day
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3 lb 8oz = 3.5 lb/ 2.2 = 1.59 kg = 1.6 kg
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1.6 kg X 60 ml = 96 ml
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Intravenous Admixtures
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IV admixtures involves the addition of one or more drugs to large volume sterile fluids.
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Example: A medication order for a patient weighing 154 lb calls for 0.25 mg of
amphotericin B (Antifungal) per kg of body weight to be added to 500 ml of 5%
dextrose injection. If the amphotericin B is to be obtained from a constituted injection
that contains 50mg/10ml, how many milliliters should be added to the dextrose
injection?
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154/2.2 = 70 kg
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50 mg
10 ml
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17.5
X ml
Dr. Osama A. A. Ahmed
70 X 0.25 = 17.5 mg
X = 17.5 X10/ 50 = 3.5 ml
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Intravenous infusions, Parenteral admixtures, and rate of
flow calculations
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Rate of flow of intravenous fluid
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Example: A medication order calls for 1000 ml of D5W to be administered over an
8-hour period. Using IV administration set that delivers 10 drops/ml, how many
drops per minute should be delivered to the patient?
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1 liter = 1000 ml
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1000 ml
480 minutes
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X ml
1 minute
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2.1 X 10 = 21 drops/ minute
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8 hours = 480 minutes
Rate of flow drops/ minute 
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Using a nomogram
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Dr. Osama A. A. Ahmed
X = 1000/480 = 2.1 ml/ min
volume infused (ml)  Drip set (drops/ ml)
Time (minutes)
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