---

- See:
      - Blood Prod Menu
      - Transfusion Therapy

- Transfusion Technique:
     - maximum time over which blood products can be administered is 4 hrs for 1 unit because of danger of bacterial proliferation & RBC hemolysis;
             - if slower infusion rate is required, half of the unit may be infused while other portion remains refrigerated in the blood bank;
     - if flow rate is interrupted for >30 minutes, unit must be discarded;
     - blood should be administered thru 170 um filters to prevent infusion of macroaggregates of fibrin and debris as well as leukocytes;

---

- Characteristics of pRBC;
    - approx 300 +/- 25 mL
    - hematocrit: 70 +/- 5%;
    - one unit of pRBCs should increase hemoglobin by approximately 1 gm/dl;
    - citrate is used as an anticoagulant in blood products during plasmapheresis;
    - citrate is converted to bicarb by liver & causes metabolic alkalosis;
    - induction of a metabolic alkalosis may produce an abrupt increase in the hemoglobinn oxygen affinity;
    - w/ transfusion actual amount of potassium administered is approx between 5.2 to 6.6 mEq per unit of pRBC;
    - since the mean age of blood administered to trauma pts is 13.5 days (and not 35 to 49 days - expiratio date of blood), the actual
             amount of potassium administered per unit may be only 1 to 3 mEq;
    - w/ massive transfusion hypokalemia is more frequently encountered than hyperkalemia;- this may be also due to alkalosis (from citrate)

---

- Complications:
    - acidemia and hyperkalemia: from massive transfusions;
            - references:
                   - Electrolyte and acid-base disturbances caused by blood transfusions.
                   - Hyperkalemia after packed red blood cell transfusion in trauma patients.
    - massive transfusion: transfusion of pRBC >6-8 units, must also provide platlets;
            - 8 units platlets for ea 10-12 units pRBC's transfused;
            - 2 units of FFP
            - Ca replacement if hypocalcemic (2nd to citrate)
    - septic reaction: considered when high fever and hypotension accompany a transfusion reaction;
    - transmission of disease:

---

- DPG:
    - w/ blood that is stored in acid citrate dextrose (ACD) solution for upto to three weeks is based on the survival of at least 70% of
           cells in recipients circulation;
    - during 3 week period, there is decline in  2-3 disphosphoglycerate (DPG) and a progressive increase in hemoglobin oxygen affinity
           (left shift of the oxygen dissociation curve);
    - after transfusion DPG levels require 24 hours or longer to return nl;

---

- Citrate toxicity:
   - can be prevented or its effects minimized by the administration of Ca;
   - historically 1gm of CaCl has been given for every four units of blood administered until such time as the pt is normothermic, euvolemic,
            and is known to have reasonably normal hepatic function;
   - if Ca gluconate is used, dose must be 4 times greater than w/ CaCl;
   - improved approach is to measure the ionized calcium level;

---