Blood Collection and Administration

I. Indications

1. Conditions causing red cell destruction such as NI or immune mediated hemolytic anemia or significant blood loss.
2. Since PCV may remain "falsely" elevated with acute blood loss the criteria for transfusion with acute severe blood loss are different than those for chronic blood loss.
3. Acute blood loss with PCV <20% may indicate need for whole blood transfusion.
4. Acute decline of PCV continuously to 12% or less.

II. Transfused Red Cell Half-Life in Neonatal Foals [3]

1. Studies have indicated longer half-life (5.5 days) than adult horses (<4 day survival).
2. Autologous RBC had half-life of 11.7 days.
3. Foal’s dam or unrelated gelding both had same half-life 5.5 days.

III. Volume of Blood to Use

1. Goal of transfusion of neonates is not to replace all lost RBC but to keep foal alive until bone marrow makes cells.
2. Half-life of transfused cells should allow time for marrow to respond in NI cases.
3. Replace 20-40% of estimated blood loss with blood transfusion.
4. Administer so as to prevent volume overload in neonates. Usually a 0.5-1 liter/hr is a reasonable rate if shock is not present using a 50% solution of red cells.
5. Previous NI treatments have described 1-4 liters of whole blood suspension.
6. The greater the volume infused, the higher the likelihood for the development of hepatopathies secondary to iron toxicosis.
7. If blood products are not readily available, synthetic oxygen carrying substances can be used (Oxyglobin®, Biopure™) in a dose of 5-7.5 ml/kg. The treatment is usually effective for 24 hours.

IV. Blood Type and Cross Match

1. Unknown Donor: Collect 10 ml yellow top ACD tube and 10 ml red top tube from recipient and donor.

1. Submit to serology lab for major and minor cross match.
2. Preferred donor is negative for blood groups A, Q, C and contains no anti-erythrocyte antibodies.
3. If blood type unknown, may need to perform unmatched transfusion and watch for immediate reaction. May sensitize foal to later transfusion reactions or in females to producing NI foals.
   Editor's Comment - Compared to being dead that’s not so bad; if urgently needs blood give it.
4. A rapid test (15 min.) was evaluated using anti-RBC sera and has been proven to be effective for detection of Aa, and Ca antigens [5].

2. Collection [4]

1. Materials

1. 10 gauge X 3 inch angiocath.
2. #15 scalpel blade.
3. Surgical gloves.
4. Blood collection set.
5. Blood bags (trauma liners) or bottles.
6. Evacuation chamber for blood bags.
7. Vacuum pump.
8. ACD solution 100 ml/liter blood.
9. 60 cc syringe.
10. 3 inch teat cannula.
11. Blood administration set.

2. Technique

1. Using syringe and teat cannula, put 200 ml of ACD solution into each 2 liter blood bag. (100 ml ACD/liter).
2. Surgically prep the skin overlying jugular vein and block with lidocaine.
3. Place the bag with ACD into the evacuation chamber connecting the bag to the chamber and the chamber to the pump.
4. Connect one end of transfer set to the adaptor (keep other end sterile).
5. With surgical gloves on, catheterize the jugular (10 ga X 3"). Be sure to first cut the skin with a scalpel blade to help overcome skin resistance. Attach blood collection set to catheter.
6. Turn on pump, set to 4-5 mmHg negative pressure.
7. Keep the jugular held off.
8. Ensure the blood and ACD are mixing well.
9. When the bag is full:
        i. Stop the pump.
        ii. Remove the adaptor from the full bag and insert into the next ACD bag (DO NOT contaminate the connector or remove the transfer set). Close the bag to atmosphere.
10. If 4 liters or more of whole blood is taken from the donor, replace this volume with LRS.
11. Wash in cold water all material having any contact with blood.
12. To simplify this, consider purchasing a blood collection kit from Veterinary Dynamics Inc. and keeping it on hand with instructions and all connections needed. 800-654-9743 or 805-4343840.

3. Adverse Reactions

1. Severe anaphylaxis may occur - Treat with epinephrine and NSAID and antihistamines.
2. Mild reactions may need to slow administration rate.
3. Consider pre-transfusion medication with flunixin, antihistamine and/or short acting steroid.
4. With cross matching should have fewer problems.

4. Handling [4]

1. Sodium citrate is the preferred anticoagulant for immediate use; blood:sodium citrate: 9:1.
2. Heparin should not be used when transfusing >1 liter of blood as bleeding problems could arise with its use in larger volumes.
3. Most whole blood is used immediately; if not, anticoagulant storage medium is required.

1. ACD-3 week storage in humans.
2. CPDA-1 (citrate-phosphate-dextrose-adenine); popular in human medicine.
3. Bacterial contamination can preclude any storage.
4. Commercial CPDA-1 bags have been shown to be the most suitable for storage [6].

4. Plastic containers, i.e., bags, do not activate Factor XII or platelets, do not injure RBCs, are unbreakable, store easily.
5. Whole blood or packed RBCs should be refrigerated at 4°C if not used immediately.

5. Administration

1. As for plasma. In-line filters must be used to remove clots.
2. In foals with neonatal isoerythrolysis (NI):

1. Exchange transfusion with blood from suitable donor. See Neonatal Isoerythrolysis for method.
2. Washed RBCs suspended in isotonic saline (0.9%) 50:50.
3. Alternately, foal's dam, gelding, Shetland pony (have a low incidence of A and Q alloantigens) may be suitable donors.
4. Watch the foal for adverse reactions. If noticed, stop the IV drip and evaluate respiration, circulation and treat accordingly.