Lab Math Flashcards
Calculation for Dilution
V1C1=V2C2 remember to subtract or add for the total volume when asking for quantity to dilute.
1 inch = how many cm
2.54cm
1 kg = how many lb
2.2 lb
RHIG formula
% of fetal cells/ mother cells multiply by 5000mL= FMH quantity/30 (30uL is covered by any one Rhig vial) To this final number at 1 vial to be on the safe side
Exchange transfusion (Mixing plasma and RBCs)
V1C1=V2C2 remember to subtract or add for the total volume when asking for quantity to dilute. Final volume is total final volume, not the diluent.
Antigen screening calculation
% Ag Neg/100=Units needed/X units to screen. Units needed/%antigen negative
Blood volume calculation
convert lbs to Kg. 1kg=75ml/Kg of blood this is the blood volume
Plasma volume
Blood volume (hct%)=X, BV-X= plasma volume. BV(1-HCT)
Maximum blood bolume collected according to AABB
10.5mL/ Kg, don’t forget 50mL diversion pouch
Component yield
Total plt= (Plt/uL) (10^3uL/mL)(vol in unit). PC/WB=% of yield. With a WB unit you do the count of the WB unit and the count of the PC (platelet concentrate and then take a percentage)
Average yield of a platelet unit
69%
Half life of IgG
23-25 days
Cryo dosing (Factor VIII)
(PV)(Factor VIII increment)/ 80IU per bag
Factor VIII quantity in severe hemophilia
Assume 0%
normal Factor 8 quantity in cryo bag
80IU/bag
Corrected Count Increment
(New ct-Old ct) (BSA)/(Plt)(x10^11)
Average BSA if not given
2m^2
successful vs. unsuccesful platelet recovery (CCI)
> 7500 successful <7500 on two subsequent transfusions= refractory.
Plasma exchange
the same as plasma volume really, just depends on how many times you want to exchange the patients plasma and multiply that but the final number. BV(1-hct) =PE
Hardy Weinberg Equilibrium
p+q=1, p^2+2pq+q^2=1. q^2 = percentage of homozygous negative- use this as the initial portion of the calculation
RR
HLA and disease correlation. Draw a graph is the first step and plug the numbers into the graph. (Positive/Positive#)x(Negative/Negative#)/ (Pos/Neg#)(Neg/Pos#)
RCF
relative centrifugal force=(28.38 or 11.17)(r)(rpm/1000)^2
Sensitivity
TP/(TP+FN)
Specificity
TN/(TN+FP)
RCF incheas value
28.38
RCF cm value
11.17
FTE formula
determine the acutal time worked per person (deduct vacation sick days etc). - factor in productivity (in a percentage) convert all units to min/yr. FTE= annual test workload (always provided)/annual workload (productivity and vacation info provided)
Staffing budgeting compare cost
determine quantity of test (min/year)/ annual workload (minutes/year) this is the total FTE needed, compare the FTE and salary vs. the cost of the test/year to determine which saves more money
Requirement for fibrinogen in cryo unit
> /=150
half life of IgG
21-28 days
Half life of IgM
5 days
Half life of factor VII
5 hours
Half life of factor VIII
8-12 HOURS
Half life of Factor X
20 HOURS
calulating yield of cryo
units of factor 8/mL x mL of final product divided by (units of factor 8/mL x mL of original FFP product) = percentage
1 plasma volume exchange removes approximately how much of material?
65%
calculating the allowed amount in donors under 110lb
450(normal amount of blood allowed)x donor weight lb .110lb= amount left
amount of anticoagulant used
450mL +/- 10% =63 mL anticoagulant. 500mL +/- 10% = 70mL
recalculate the amount of anticoagulant needed for donor unit when patient is less than 110 lb
63mL/110lb=amount needed (mL)/donor weight (lb)
how much fibrinogen is in one bag of cryo
250 mg/ bag
BV for IUT
0.14 mL/g
IUT calculation
(fetus weight in grams) (0.14mL/g)(desired change in hematocrit) / hct of unit to transfuse
quantity of one reagent drop used in blood testing
50uL
formula for conversion celsius to farenheit
T in celsius= (Tin farenheit-32) x 5/9
