Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
36 Cards in this Set
- Front
- Back
|
What determines the antigens on RBCs? |
3 genes on chromosome 9 (A, B, O) |
|
|
When do antigens on RBCs begin to appear? |
ABO antigens begin to appear on fetal RBCs in utero (6 weeks gestation); reach adult levels by age 4 |
|
|
When do antibodies to RBCs begin to appear? |
ABO antibodies do not begin to appear until after 4 months of age; reach adult levels by about 10 years |
|
|
How do you determine what RBC antigens are present? |
Blood typing: - The patient’s plasma is mixed with commercially supplied antigens. |
|
|
Who develops antibodies to the Rh group? |
Patients who are Rh negative have the ability to make the "anti-D antibody"
Not naturally occurring; patient needs exposure to Rh antigen to develop anti D antibody: |
|
|
What are the implications of being "Rh positive"? |
Will not develop anti-D antibody |
|
|
What are the implications of being "Rh negative"? |
Can potentially develop the anti-D antibody |
|
|
What does a "type and screen" accomplish? |
Determines ABO/Rh Type
If antibody screen reveals an unexpected antibody, then it is identified and the blood bank will set aside units of blood lacking the corresponding antibody |
|
|
What is the process of a "type and screen"? |
Screening |
|
|
What does a "type and cross-match" accomplish? |
Trial transfusion in a tube: |
|
|
When a blood ABO-Rh "type" is done, what are the chances of having a reaction? |
1/1000 chance the patient will have a reaction to the blood |
|
|
When a blood "screen" is done, what are the chances of having a reaction? |
1/8000 chance patient will have a reaction to the blood. |
|
|
When a blood "cross-match" is done, what are the chances of having a reaction? |
1/10,000 chance patient will have a reaction to the blood. |
|
|
In an emergency can you give blood to a patient who hasn't had a "type and crossmatch"? |
Yes - with a type and screen it is a 1/8000 chance vs with a type and crossmatch it is a 1/10,000 chance |
|
|
What are the most common complications of a blood transfusion? How common? |
- FNHTR: Febrile Non-Hemolytic Transfusion Reaction - 1/100 - Allergic reaction (urticaria) - 1/100 - TACO: Transfusion Associated Circulatory Overload - up to 1/100 |
|
|
What is FNHTR? |
FNHTR: Febrile Non-Hemolytic Transfusion Reaction - Increase in temperature of 1 C or 2 F with no other explanation - Most common transfusion reaction (1%) |
|
|
What if a patient has FNHTR (febrile non-hemolytic transfusion reaction)? |
Transfusion must be stopped |
|
|
What causes FNHTR (febrile non-hemolytic transfusion reaction)? |
Increased pyrogenic cytokines |
|
|
What is the second most common transfusion reaction after FNHTR? |
Allergic reaction (urticaria) - usually just localized hives |
|
|
What causes an allergic reaction after a transfusion? |
Type I hypersensitivity to donor plasma proteins |
|
|
How do you treat a patient having an allergic reaction after a transfusion? |
Diphenhydramine (Benadryl)
Transfusion may be restarted after localized urticarial reaction clears and there are no other accompanying signs/symptoms |
|
|
What increases a patient's likelihood of developing transfusion acquired circulatory overload? |
- Large quantity of blood products transfused - Rapid infusion rate |
|
|
What can transfusion acquired circulatory overload be confused for? |
Transfusion Related Acute Lung Injury (TRALI) |
|
|
What are the similarities between transfusion acquired circulatory overload and transfusion related acute lung injury? |
- Signs/symptoms of cardiac failure |
|
|
What are the signs of transfusion related acute lung injury? |
Acute lung injury which occurs within 6 hours of a transfusion |
|
|
What causes transfusion related acute lung injury? |
Platelet products is the most frequent cause |
|
|
What is the #1 cause of transfusion-related fatality in the US? |
Transfusion Related Acute Lung Injury |
|
|
How do you calculate the allowable blood loss? |
= EBV (Hct-i - Hct-f) / Hct-f
EBV = Estimated Blood Volume = Weight (kg) * 70 Hct-i = Initial Hct Hct-f = Minimal allowable Hct |
|
|
What are the indications for PRBC transfusion? |
- Hgb < 6
- Hgb 6-10 AND current ongoing bleeding or potential for ongoing bleeding OR signs of end-organ ischemia |
|
|
What can happen if the Hgb <6? |
Inadequate splanchnic and preportal oxygen delivery and consumption when Hgb < 6 g/dL |
|
|
What signs of end-organ ischemia with a Hgb between 6-10 would make you transfuse PRBCs? |
- ST changes on EKG |
|
|
What do you need to check before transfusing a patient? |
- Double check on the compatibility of the blood with the patient. |
|
|
After the blood products are checked, what happens to the blood before it enters the body? |
PRBC’s must be run through a fluid warmer before reaching the patient
PRBC’s should be hung on a line with normal saline
|
|
|
Why must blood products be run through a fluid warmer before entering the patient? |
- PRBC’s are stored at 4 C |
|
|
Why must blood products be hung with NS vs LR? |
Lactated Ringer’s solution contains calcium, which is involved in the clotting cascade.
Running PRBC’s on an LR line can lead to microclotting of the blood within the IV line |
|
|
Why must blood products be stored at a cold temperature? |
Blood that has been out of refrigeration for >30 min can warm, causing the blood to “spoil” If the blood is not going to be used immediately, it should be placed in the refrigerator |
