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.
Calculating infusion rate of factor 8 in hemophiliac
The t1/2 of factor 8 is 12 hours
So if we determine the total units of factor 8 needed, then half of it will remain after 12 hours.
For example: if total calculated units needed is 3000 then 1500 units will remain after 12 hours. Maintenance infusion rate would be 1500 units in 12 hours = 125 units per hour.
How factor 8 administered in hemophiliac
Either factor 8 concentrate or Cryo (about 10 units/ml)
Dose of furosemide to counteract the effect of increased ADH due to pain stimulation or positive pressure ventilation is …
0.1 mg/kg
What is the universal donor blood type? And what would you do if you gave it in emergency then later patient’s blood type reveals?
Type O, Rh-negative (pRBC preferable over plasma, as plasma has anti-A and B Ag’s)
If 2 or more units of type O-negative given uncrossmatched and subsequent blood type reveals the patient blood type, then switching back to the patient’s own blood type could lead to major intravascular hemolysis of the transfused RBC and therefore it is advised not to be done.
Why platelets stored at room temperature 22C -/+2 ?
Because at pH below 6 or in cold temp such as 4C (temp used in storage other products), platelets undergo irreversible shape changes (lose platelets function).
2 down sides of storage at room temp:
1) bacterial growth
2) the pH falls because of platelets metabolism
To minimize these problems, platelets storage limited to 5 days at 22C
Citrate Toxicity risk when while blood transfused at rate of …. and clinically manifest as …
> 50 mL / 70 kg / min
Translate decrease in ionized Ca -> prolonged QT interval -> increase LVEDP -> hypotension
Ionized Ca returns to normal within 5 min of stopping transfusions
Max allowable blood loss =
EBV x (Hct start - Hct lowest acceptable)/ Hct start
EBV by age Preterm 100-120 ml/kg Term 90 ml/kg Infant 80 ml/kg >1 yr 70 ml/kg Adult 65 ml/kg
calculating the dose for correction of hyponatremia?
Needed Na dose = TBW x 0.6 x (desired Na - current Na)
Infusion of 3% NaCl should not be > 2 mL/kg/hr to prevent central pontine myelinolysis
Once levels reaches 120 mEq/L, further management is by fluid restriction and diuretics
What is type of blood product can be given in emergency if O negative RBCs not available?
O positive RBC
For childbearing age women is not recommended to get Rh positive RBC unless Rh negative not available, this is because they will develop isoummunization if they receive Rh positive and erythroblastosis fetalis developer if future fetus is Rh positive.
Hetastarch interfere with coagulation system through interacting with …
One L of 6% solution (Hespan) reduces factor 8 : C levels by 50% and will prolong the PTT
pRBC cooled to about … to …
4 C to decrease cellular metabolism
pRBC preservatives for stronger are added for what purpose?
CPDA-I (Citrate PO4 Dextrose Adenine) Citrate -> Po4 -> Dextrose -> Adenine->
CPDA-I -> anticoagulant
Citrate -> to bind Ca and acts as anticoagulant
PO4 -> acts as buffer
Dextrose added at the day of donation as energy source for metabolism (it raises BG up to 400 and by day 35, BG falls to 100
Adenine-> to produce ATP
Characteristics of stored pRBC after 35 days
PH falls to 6.7
Potassium increases from 4 to 76 mEq/dL
2,3-DPG fall below 1 which causes leftward shift in oxyHgb dissociation shift and allow increase O2 affinity and produce P50 < 26 mmHg
Life long storage of blood stored with following
CPD (citrate Po4 Dextrose)
CPD + adenine
Adsol(AS-1), Nutricel (AS-2), Optisol (AS-3)
21 days
35 days
42 days
LMWH can be monitored by levels of …
Anti-Xa levels
vWBD types
Type 1 most common -> decrease in factor 8 but normal bleeding time (quantitative decrease due to decrease in release of available vWF.
Type 2 -> qualitative deficiency of vWF
Type 3 most sever and rarest-> almost no vWF and very low factor 8
Treatment of vWD with?
Products that contains vWF and Factor 8 (Cryo, FFP, or Factor 8 concentrate).
Recombinant factor 8 is not used because it dose not contain vWF
Number 1 mortality associated with transfusion is
TRALI 51%
Non ABO hemolytic transfusion rxn 20%
Microbial infection 12%
ABO hemolytic transfusion rxn 7%
TACO 7%
Which is the process done to reduce CMV transmission and Reduce GVHD
Leukoreduction for CMV
Irradiation products to inactivate donor-lymphocytes to reduce GVHD
