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EVANS BLUE INJECTION. U.S.P.
FOR INTRAVENOUS USE ONLY
DESCRIPTION:
Evans Blue Injection is a sterile, solution of Evans Blue (T-1824) in water
for injection. Each ml. contains not less than 4.30 mg and not more than 4.75 mg of C34H24N6Na4O14S4
INDICATIONS:
ACTIONS:
Evans Blue is firmly bound by plasma albumin and leaves the vascular system very slowly, thus
making it ideal for measuring blood volume. Small quantities of dye may be detected in the bile and tissue phagocytes, but the majority disappears into extra vascular cells, lymphatic spaces
and the reticularndothelia system. Evans Blue does not pass into the cerebro spinal fluid or pass the placenta barrier. Mixing of dye in the blood is usually complete within ten minutes after
injection although this may vary up to fifteen minutes in patients with prolonged circulation times as seen in shock or congestive hearth failure.
CONTRAINDICTIONS:
PRECAUTIONS:
Staining of the skin has been reported. Precautions should be taken to minimize the possibility of staining.
ADVERSE REACTIONS:
Except for staining as mentioned in Precautions, doses several times greater than the usually administered dose induce no obvious toxic effects.
DOSAGE AND ADMINISTRATION:
Many published papers and standard texts exist for techniques and calculations. These are
available free from the suppliers on request. One such technique is given below:
Blood volume should be determined when the subject has fasted for at least 12 hours to avoid
lipemia. Prior to the test the subject should rest in the supine position for a minimum of 20 minutes. All glassware and instruments should be thoroughly clean and dry. syringes and
paraffin to reduce haemolysis. The blood sample must be drawn only after release of the tourniquet. Samples should be placed in tubes containing dry heparin or sodium potassium
ammonium ozalist anticoagulant, Samples should be discarded if there is visible haemolysis.
Apparatus:
1. A spectrophotometer or photometer with a narrow band filter in the range of 610-620 millimicrons.
2. A means of determining the hematocrite reading.
3. Oxalated tubes to contain 10ml quantities of blood.
4. three clean dry sterile cool quality syringes.
5. A stop watch.
Reagent: Evans Blue injection in 5ml ampules of 5mgs/ml.
Technique:
1.Using a sterile dry syringe collect 10ml of blood without stains from the antecubital vein.
Detach the syringe from the needle: express the blood into a tube labeled dye free plasma, inverting several times to ensure solution of the anticoagulant.
2.Attach a syringe containing the measured amount of dye solution to the needle already in
the vein. Note the time and inject the dye slowly. The syringe is filled and emptied at least five times with the subjects blood to ensure complete flushing of all traces of dye. The amount of
dye injected is indicated by the following table:
Under 100Lbs (45.45Kg) 10mg 0.5
100Lbs to 180Lbs (45.45 to 81Kg) 15mg 0.75
Over 180Lbs (81Kg) 20mg 1.0
3. Approximately nine minutes after beginning the injection of dye, a clean needle on a clean
syringe is inserted into the apposite antecubital vein. Exactly ten minutes from the beginning of the injection of dye, withdraw 10ml of blood. Deliver this into an oxaiadate tube marked dyed plasma.
4. A curvette containing the dye free plasma is set in the spectrophotometer and the
instrument is adjusted to zero optical density at 610ny. The dye plasma is then inserted and its optical density (D) at 610 mu is read.
5. Determine the value of packed cells (hematocrite reading).
Calculation: The total plasma volume is determined according to the following formula:
20 K
Plasma Volume = - - x F
D
The constant K is the same for each dye lot. It is determined in the following manner. Dilute
2ml of dye solution to 250ml with water in a volumetric flask. Deliver 5ml of the diluted dye into a 50ml volumetric flask containing about 40ml of 0.9% saline. Add 0.5ml of clear plasma
and adjust volume with saline. This final dilution contains a dye concentration in plasma of 0.004mg per ml (4mcg per ml). The optical density of this standard is determined at 610 mu
using the control blank of 0.5ml of the clear plasma diluted to 50ml with 0.9% saline.
D
K = --- (where D is the optical density and C = 0.004)
C
Plasma volume
Blood Volume = - - x 100
100 Hemotocrite
Divide the total plasma volume and also the whole blood volume by the subjects weight in
Kilograms to determine plasma volume from each kilogram and the whole blood volume for each kilogram.
Clinical diagnosis by laboratory Method. 12th Edition. Todd, Sandford and Watts.
HOW SUPPLIED:
Evans Blue Injection U.S.P. supplied in 5ml ampules each containing 25mg of Evans Blue. Packaged and shrink wrapped in packs of 10 ampules.
STORAGE:
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