Blood Banking and Blood Products

Question 1

Blood Products Preparation

Answer 1

Prescription is needed for dispensing blood products as a treatment

Donors’ whole blood (approx. 500ml) is collected in anticoagulated bags –> spun down and separated according to their density

Question 2

FFP

Answer 2

Fresh Frozen Plasma

Indications

• multiple coagulation deficiencies due to liver failure
• diseminated intravascular coagulopathy (DIC)
• vitamin K deficiency
• warfarin toxicity
• massive blood loss

Question 3

Platelet concentrates

Answer 3

Normal platelet count 150-450,000/ul

Indications: Thrombocytopenia (<50,000 if symptomatic, <10,000 if asymptomatic). This is caused by decreased platelet production (e.g. chemotherapy) or increase destruction (e.g. DIC). Massive blood loss.

Each unit of platelet concentrate should increase the platelet count 5000-10,000/uL. Usually a pool of 6 units are used in one transfusion.

Question 4

PRBC

Answer 4

Packed RBCs

Indications: Increase in oxygen-carrying capacity. Hemodynamically unstable. These patients may experience P>100/min, RR>30/min, hypotensive, decrease O2 sats, dizziness, weakness, angina, and alter mental status. The decrease in RBCs might also due to leukemic processes, hemolytic anemia, other anemias, surgical or traumatic blood loss. The transfusion criteria is usually hgb of <8g/dl, however, if patient is hemodynamically unstable, decision of PRBCs transfusion should be considered.

Question 5

Albumin

Answer 5

Prepared by isolating and purifying albumin from FFP. The indication of use is to bring the osmotic pressure of intra and extra-vascular back to normal in situation of hypovolemia and hypoproteinemia.

Question 6

ABO Blood Typing

Answer 6

ABO antibodies are present starting at 3 months after birth and are present throughout life

Question 7

Rh Blood Group

Answer 7

Named after Rhesus monkeys

Rh or D antigen is present at birth, but anti-D antibodies are not present until exposure. Subsequent transfusion or exposure can be a problem.

Rh + 70%

Rh - 30%

Question 8

Compatibility testing for transfusion

Answer 8

Ensure safety for the recipient

RBCs - type and screen or type and crossmatch. RBC’s have over 1,000 antigens on their surface. Compatibility testing screens for atypical antibodies (Kell, Duffy, Lewis, etc.) which follow the same timeline as the development of anti-D antibodies.

Question 9

Trauma Situation - what type do you give?

Answer 9

O Negative

But be aware of risks that there are many other antigens that could be present that could cause agglutination and reaction.

Question 10

Universal donor for FFP

Answer 10

AB (-/+) because there are no anti-A or anti-B antibodies

Question 11

Complications and risks of transfusion

(Emergent)

Answer 11

**Hemolytic transufsion reactions **

• most likely cuased by ABO incompatibility. Rare but most severe and is usually a human error.
• RBCs lyse and inc K+ and Hgb which is hard on the kidneys
• Clinical presentations:DIC, Acute Renal Failure, Acute Tubular Necrosis, Shock. The triads of Fever, Flank pain and red/brown urine occasionally occur.
• MEDICAL EMERGENCY, STOP TRANSFUSION.

**Anaphylactic Transfusion Reactions **

• shock, HoTN, angioedema, respiratory distress
• Tx with Epi

**Transfusion Related Acute Lung Injury **

• Rare, and etiology unknown
• Clinical presentations:Sudden onset of respiratory distress during or after transfusion of blood products. Fever, tachypnea, tachycardia, and hypotension can occur.
• Tx: supportive - mechanical ventilation required majority of the time

Question 12

Complications and risks of transfusion

(Nonemergent)

Answer 12

Febrile nonhemolytic transfusion reactions

• reaction to interleukins and TNF alpha substance in blood products.
• Clinical presentation: fever, chills, rigors, mild dyspnea
• Tx: looks like hemolytic transfusion rxn so stop transfusion and tx with tylenol and benedryl which are usually effective

Delayed hemlytic transfusion reactions

• caused by atypical antibody present in recipient. Occurs 2-10 days post transfusion
• Clinical presentations: Symptoms are much less severe than acute reactions. Slight fever, falling hematocrit, mild increase of unconjugated bilirubin and spherocytes in blood smears. Usually this is discovered by the blood bank staffs in patients with new alloantibodies against RBCs.
• No tx necessary, but be cautious with subsequent transfusions

**Urticarial Transfusion Reactions: **

• presents with hives or urticaria
• Tx with Benadryl PO or IV. if no other signs are present, continue with transfusion

**Post Transfusion Purpura (PTP): **

• Very rare.
• severe thrombocytopenia lasting days to weeks 5-10 days post transfusion associated with sensitization to a foreign antigen from previous platelet containing transfusion
• tx with high dose corticosteroids and IVIG

Question 13

Hemolytic Disease of Newborn

Answer 13

Mother is Rh-, first fetus is Rh+, which builds up Rh antibodies, then second fetus who is Rh+ is aborted because attacked by antibodies

Tx ppx with Rhogam (RhIG) which coats fetal red cells so immune system is not stimulated and no antibodies are created