RISA or HISA - Plasma Volume Protocol

1. Inject the entire contents of IHSA I125 ISOJEX syringe, IV and flush the syringe several times with the patient's blood. Dose is between 10 - 20 :Ci.
2. Wait at least 5 to 10 minutes and withdraw 20 mL of blood that contains an anticoagulant
3. Remove a sample for a Hct determination
4. Pipette 4 mL of whole blood and place into a counting vial and label WB
5. Centrifuge the remaining blood and remove 4 mL of Plasma, label Pl
6. From the kit take out the standard and count for about 5 minutes (you must get at least 10,000 counts)
7. Count Bkg for the same amount of time
8. Count then WB and Pl samples and apply the formulas below:

Additional Comments regarding this procedure

1. Why is it necessary to calculate a radioactive Hct when you have already measured the patient's Hct?
2. If Red Cell Volume is required always complete HISA first. Consider the effects of ⁵¹Cr and ¹²⁵I when counting the patient's samples.
3. Why does the literature suggest that you take at least two patient blood samples?
4. Understand the process on how to extrapolates the sample counts back to zero time - see below
5. Two aspects that the HISA kit supplies that should be noted
   1. The HISA comes in as a unit dose
   2. A standard comes with it