Blood Products

Question 1

Rh system for RBCs

Answer 1

You either have a D protein or not.
If you have the D protein, you are Rh +
If you don’t have the D protein, you are Rh negative and have antibodies against D proteins. They can not receive Rh+ blood.

Question 2

Universal donors

Answer 2

RBCs = O negative
Plasma = AB positive

Note that plasma is always the complete opposite of RBC compatibility

Question 3

Universal Recipients

Answer 3

RBCs = AB positive
Plasma = O negative

Note that plasma is always the complete opposite of RBC compatibility

Question 4

Type, screen, and cross

Answer 4

Typing = determining presence of ABO and Rh-D antigens (takes 5 min). Looks at surface proteins. Prevents 99.8% of transfusion reactions.

Screening = determining the presence of most clinically significant ANTIBODIES (takes about 45 min). This is looking for antibodies, not surface proteins.

Crossing = mixing blood with unit planned on being transfused (takes 45 minutes)

Question 5

Emergency RBC transfusion from most to least desirable when you can’t get full T&S

Answer 5

1) Type specific partially crossmatched
2) Type specific uncross matched
3) O negative uncrossmatched

Question 6

Pts with CAD should be transfused once Hct is around

Answer 6

28-30%

Question 7

Hub value after acute blood loss

Answer 7

Will be the same as your initial. If you rapidly lose 1L of blood, the concentration in the blood stream is still the same, no time for fluid rebalancing yet (no hemodilution)

Question 8

What does phosphate do in stored blood?

Answer 8

Buffer against acidosis.

RBCs do NOT have mitochondria. Therefore they rely on anaerobic metabolism to convert glucose to ATP – risk of acidosis!

Blood is stored at 1-6 degrees C to extend the lifespan of RBCs by slowing glycolysis

Question 9

What does adenine do in stored blood?

Answer 9

Substrate for ATP synthesis

Question 10

Hct of PRBCs

Answer 10

70%

Question 11

How do PRBCs affect the dissociation curve?

Answer 11

Banked blood has lower levels of 2,3-DPG = shift to left, and impairs O2 unloading to the tissues.

Question 12

Blood component processing

Answer 12

Leukoreduction = removing WBCs to prevent HLA aloimmunization

Washing = prevents anaphylaxis in IgA deficient patients

Irradiation = prevents graft vs. host disease

Question 13

Most common diseases from blood transfusion

Answer 13

1) CMV
2) Hep B
3) Hep 3
4) HIV

Question 14

In up to ___% of Hep C infections, it can cause cirrhosis, liver CA, failure and death

Answer 14

85%

Question 15

Why do we give sodium bicarb in transfusion reactions?

Answer 15

Alkalinizes the urine to reduce Hgb precipitation in the tubules.

WE also give fluid bolus to help wash the Hgb out of the tubules.

Question 16

S/S of acute hemolytic transfusion reaction

Answer 16

Observed under anesthesia:

1) Hemoglobinuria (usually the presenting sign!!!)
2) Hypotension
3) Increased surgical bleeding

Masked by anesthesia:

• fever
• chills
• chest pain
• dyspnea
• nausea
• flushing

Question 17

How does DIC start from a transfusion reaction?

Answer 17

Erythrocyin is released from RBCs and activates the intrinsic cascade!
Leads to uncontrolled fibrin formation and uses all the body’s platelets, and factors 1, 2, 5, and 7

Question 18

Treatment of acute hemolytic transfusion reaction

Answer 18

• stop the transfusion
• Keep UO > 75-100mL/hr with IVF, mannitol, or lasix (if mannitol doesn’t work)
• Give Na Bicarb to alkalinize the urine
• Send urine and plasma hub samples to the blood bank
• Check plts, PT, and fibrinogen to look for DIC
• Send any unused blood to the blood bank to double check for cross match
• Support BP with IVF and pressers as needed

Question 19

What is better, salvaged (cell saver) or banked blood?

Answer 19

Salvaged blood. Has higher levels of 2,3-DPG and ATP and are better able to keep their biconcave shape

Question 20

Cell saver contraindications

Answer 20

• Oncological procedures (CA procedures)
• Infected surgical site
• Sickle cell disease
• Thalassemia
• Topical drugs in the surgical field (butadiene, chlorhexidine, topical antibiotics, chemo, etc)

Question 21

Why is cell saver controversial in c-seciton?

Answer 21

Risk of amniotic fluid embolism (anaphylactoid syndrome of pregnancy)