Lab Math

Question 1

Calculation for Dilution

Answer 1

V1C1=V2C2 remember to subtract or add for the total volume when asking for quantity to dilute.

Question 2

1 inch = how many cm

Answer 2

2.54cm

Question 3

1 kg = how many lb

Answer 3

2.2 lb

Question 4

RHIG formula

Answer 4

% 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

Question 5

Exchange transfusion (Mixing plasma and RBCs)

Answer 5

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.

Question 6

Antigen screening calculation

Answer 6

% Ag Neg/100=Units needed/X units to screen. Units needed/%antigen negative

Question 7

Blood volume calculation

Answer 7

convert lbs to Kg. 1kg=75ml/Kg of blood this is the blood volume

Question 8

Plasma volume

Answer 8

Blood volume (hct%)=X, BV-X= plasma volume. BV(1-HCT)

Question 9

Maximum blood bolume collected according to AABB

Answer 9

10.5mL/ Kg, don’t forget 50mL diversion pouch

Question 10

Component yield

Answer 10

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)

Question 11

Average yield of a platelet unit

Answer 11

69%

Question 12

Half life of IgG

Answer 12

23-25 days

Question 13

Cryo dosing (Factor VIII)

Answer 13

(PV)(Factor VIII increment)/ 80IU per bag

Question 14

Factor VIII quantity in severe hemophilia

Answer 14

Assume 0%

Question 15

normal Factor 8 quantity in cryo bag

Answer 15

80IU/bag

Question 16

Corrected Count Increment

Answer 16

(New ct-Old ct) (BSA)/(Plt)(x10^11)

Question 17

Average BSA if not given

Answer 17

2m^2

Question 18

successful vs. unsuccesful platelet recovery (CCI)

Answer 18

> 7500 successful <7500 on two subsequent transfusions= refractory.

Question 19

Plasma exchange

Answer 19

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

Question 20

Hardy Weinberg Equilibrium

Answer 20

p+q=1, p^2+2pq+q^2=1. q^2 = percentage of homozygous negative- use this as the initial portion of the calculation

Question 21

RR

Answer 21

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#)

Question 22

RCF

Answer 22

relative centrifugal force=(28.38 or 11.17)(r)(rpm/1000)^2

Question 23

Sensitivity

Answer 23

TP/(TP+FN)

Question 24

Specificity

Answer 24

TN/(TN+FP)

Question 25

RCF incheas value

Answer 25

28.38

Question 26

RCF cm value

Answer 26

11.17

Question 27

FTE formula

Answer 27

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)

Question 28

Staffing budgeting compare cost

Answer 28

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

Question 29

Requirement for fibrinogen in cryo unit

Answer 29

>/=150

Question 30

half life of IgG

Answer 30

21-28 days

Question 31

Half life of IgM

Answer 31

5 days

Question 32

Half life of factor VII

Answer 32

5 hours

Question 33

Half life of factor VIII

Answer 33

8-12 HOURS

Question 34

Half life of Factor X

Answer 34

20 HOURS

Question 35

calulating yield of cryo

Answer 35

units of factor 8/mL x mL of final product divided by (units of factor 8/mL x mL of original FFP product) = percentage

Question 36

1 plasma volume exchange removes approximately how much of material?

Answer 36

65%

Question 37

calculating the allowed amount in donors under 110lb

Answer 37

450(normal amount of blood allowed)x donor weight lb .110lb= amount left

Question 38

amount of anticoagulant used

Answer 38

450mL +/- 10% =63 mL anticoagulant. 500mL +/- 10% = 70mL

Question 39

recalculate the amount of anticoagulant needed for donor unit when patient is less than 110 lb

Answer 39

63mL/110lb=amount needed (mL)/donor weight (lb)

Question 40

how much fibrinogen is in one bag of cryo

Answer 40

250 mg/ bag

Question 41

BV for IUT

Answer 41

0.14 mL/g

Question 42

IUT calculation

Answer 42

(fetus weight in grams) (0.14mL/g)(desired change in hematocrit) / hct of unit to transfuse

Question 43

quantity of one reagent drop used in blood testing

Answer 43

50uL

Question 44

formula for conversion celsius to farenheit

Answer 44

T in celsius= (Tin farenheit-32) x 5/9