Blood, Fluid Therapy Flashcards
How much one unit platelet increases platelets count in 70-kg person?
5000-10,000/mm3 per unit
Each unit contains 5.5x10(10) platelets
Most common inherited coagulopathy is …
Von Willebrand’s diseases (Affects 1 in 100-500)
Hemophilia A (1-2 in 10,000)
Hemophilia B (1 in 100,000)
To avoid hemolytic transfusion rxn before giving platelets, …. processes done.
Rh matching
Platelets contains mostly plasma and WBC with relative few amount of RBCs,
The small amount of RBCs in platelets can cause Rh immunization if Rh (+) platelets concentration injected into Rh(-) patients. This is important for Rh(-) pregnants which only should receive Rh(-) until childbirth.
ABO-compatibility?
although it has noted adequate hemostasis without ABO compatibility, if done it’ll give platelets better survival chance and cross matching for subsequent RBCs is easier.
PT used to evaluate coagulation factors …
PTT evaluates …
7 (Extrinsic pathway) and 1952
PTT -> factor 8 & 9 (Intrinsic pathway) as well as 1952
The 3 main blood compatibility tests that can be preformed to reduce chances of hemolytic rxn are … and their possible incompatible rxn ?
1) ABO and Rh typing, the possibility of incompatible transfusion is less than 1:1000
2) Type and screen; if it is added to ABO and Rh, the possibility of incompatibility is less than 1:10,000
3) optimal safety occurs when crosshatching is preformed.
Frozen erythrocytes can be stored for how long?
10 years from the time of collection
The shortest t1/2 clotting factor is …
VII (4-6 hours)
It’s first factor become deficient inpatients with sever liver failure, warfarin therapy, or Vit K deficiency.
Which factor not synthesized in the liver?
Factor 8
Synthesized in vascular endothelial and megakaryocytes and it’s involved in promoting clothing through intrinsic pathway.
Which blood product has the highest risk for bacterial sepsis?
Platelets (1:12,000)
The source can be from donor blood or from contamination during process of preparation. And it’s stored at room temperature at 20-24 C which bacteria tend to survive and multiply.
All other products stored at 4C or lower (FFp and Cryo at -70C). Albumin is heat sterilized and stored safely at room temp.
Screening tests in all blood units are …
HIV 1 & 2 HCV HBV HTLV 1 & 2 West Nile virus
Blood volume by age;
Preterm Term Infant (3-12 months) >1 year Adult
100-120 ml/kg 90 ml/kg 80 ml/kg 70 ml/kg 65 ml/kg
The most common transfusion associated infection is …
CMV <1%
HBV (1:200,000) HCV (1:600,000) HTLV (1:641,000) HIV (1:800,000) West Nile virus (1:1000,000)
CMV antibodies found 40-90% in asymptomatic patients.
CMV is benign infection unless it affects immunocompromised. CMV carries in WBC, therefore leukocyte depleted blood can be used.
Primary goal of preop preparation of patients with hemophilia A is …
To increase plasma factor 8 activity that will ensure adequate hemostasis (50-100%) then maintain levels > 40% for next 7-10 days.
30% of factor levels needed for hemostasis
How to calculate the amount of factor 8 activity needed to increase the hemophiliac patient’s factor 8 level?
One unit of VIII is equal to 1 mL of 100% activity of normal plasma.
So first calculate patient’s blood and then plasma volume, then calculate the amount of activity needed to increase the factor 8 level.
1) weight x 65 ml/kg (for adults) = blood volume
2) blood volume x 0.6 (60% is plasma volume) = patient’s plasma volume
3) 1 VIII unit = to 1mL of calculated plasma volume (if needed to increase VIII activity 100%, and the plasma volume for example is 3000ml then give 3000 units, if you need to increase VIII activity only 40%, then 3000 ml of plasma x 0.4 for 40% activity = 1200 units)
Types of hemophilia A?
It’s x-linked recessives (1:5000 makes).
Types depend on % of factor 8 activity
Sever (<1% factor is active)
Moderate (1-4% is active)
Mild (5-30% factor 8 is active) and they rarely have spontaneous bleeding.
