Lab Math Flashcards
1 Kg
2.2 lbs
1 in
2.54 cm
1 kilo
1000 L, g, m
10 deci
1 L, g, m
100 centi
1 L, g, m
1000 milli
1 L, g, m
10*6 micro
1 L, g, m
1000 micro
1 milli
F*
9/5 C + 32
C*
5/9 (F-32)
%W/V
g per 100 mL of solution
%W/W
g per 100 g solution
%V/V
ml per 100 ml of solution
Adjust concentration
C1 C1 = V2 C2
Mean
average
Median
Middle value
Mode
Most frequent number
Range
High number - low number
Midrange
Low + High / 2
Sensitivity
True positive or probability disease is present when test is positive TP FP
TP / FP + FN x 100 FN TN
Specificity
True negative or probability that disease is not present when tested negative TP FP
TN / TN + FP x 100 FN TN
Positive Predictive Value
TP / TP + FP x 100
Negative Predictive Value
TN / TN + FN x 100
HLA Relative risk
( TP x TN / FP x FN ) x 100
true / false
Relative Centrifugal Force
11.17 (r) (RPM/1000)^2
r = radius in cm
Or 28.38 (r) = radius in inches
Rotations per minute (RPM)
Square root (RCF/ 28.38 x r) x 1000
Half life IgG
21-28 days
Half life IgM
5 days
Half life of Factor VII
5 hours
Half life of Factor VIII
8-12 hours
Factor IX
20 hours
Total Blood Volume in adult
Female = 60 mL/Kg
Male = 66 mL/Kg
70-75 mL/Kg (Historical)
Total Blood Volume in Preterm infant
105 mL/Kg
Total Blood Volume in term infant
85- mL/Kg
1 unit of RBC will increase H/H
Hgb 1 g/dL
HCT 3%
Yield of 1 random platelet
5.5 x 10^10 platelets
Yield of 1 apheresis platelet
3.0 x 10^11 platelets
1 random platelet should increase PLT count by
5-10,000 per unit
1 apheresis platelet should increase PLT count by
30-60,000 on adult
1 unit of FPP will increase clotting factors by
10% or 1 IU/mL
Factor VII in cryo
80 units
Fibrinogen in cryo
250 mg
VIII dose with cryo
( Plasma Volume (mL) x desired activity ) / 80
Fibrinogen dose with Cryo
( Plasma volume dL x desired volume ) / 250
Corrected Count Increament
( Post plt ct - pre plt ct ) x BSA (2) / # of plts transfused
of plts = volume x yield x 10^3 (uL) = 10^11
Success > 7500 Refractory = <7500 in 2 transfusion
Platelet yeild
Final Concentration x Final volume /
Original concentration x original volume x 100
HCT of Packed RBC
70%
% plasma removed in 1.0 volume exchange
65%
% plasma removed in 1.5 volume exchange
75%
% plasma removed in 2.0 volume exchange
88%
% plasma removed in 2.5 volume exchange
92%
% plasma removed in 3.0 volume exchange
96%
Anticoagulant 450 mL bag
63 mL
Volume drawn in 450 mL bag
405-495 mL
Anticoagulant in 500 mL bag
70 mL
Volume drawn in 500 mL bag
450-550 mL
450 mL bag low volume
300-404 ml
500 mL bag low volume
333-449 mL
IUT
Fetus wt in g x .14 x HCT increament / HCT of RBC
RHIG dosing
FMH = # fetal cells x 5000 / # maternal cells
Rhig = Volume of FMH / 30 ml plus 1 vial
RBC volume increase in neonate
10 mL/kg raises hct by 2-3 g/dL in a neonate
multiply by baby’s weight in kg
additive RBC’s with 65% HCT = 2 g/dL
Packed RBC’s with 80% HCT = 3 g/dL
What % of transfused donor cells die each day?
1% of RBC will die each day
Calculate how much FFP to give to raise coag levels by X %?
PV x (% increase - % current) = mL of FFP 1 unit = 200-250 mL
How do you calculate platelet yield for random donor platelets?
PLT in plasma / (Volume of WB x Donor PLT Ct) x 100
Don’t forget units!
PLT Count is # of PLT’s x 1000/ul
PLT Count of 240 = 240,000/ul
How do you calculate F-VIII yield in Cryo?
F-VIII/mL x mL of final /
F-VIII/mL x mL of original FFP x 100
How do you calculate Fibrinogen yield in Cryo?
Fib/mL x mL of final /
Fib/mL x mL of FFP x 100
*Fibrinogen is mg/dL so convert to mL
1 dL = 100 mL
Calculate how much FFP to give to a neonate
10-15 mL/kg will increase factors by 15-20%
Calculate how much PLT to give to a neonate
5-10 mL/kg will increase platelets by 50-100,000/uL
What is the specific gravity of whole blood?
1.053
How much anticoagulant is in whole blood?
Anticoagulant is 14 mL/100 mL or 0.14 mL per mL whole blood
What is the max Extra-corporal Volume
15% of total blood volume.
Example: 150 lb male patient = 68.2 kg x 66 ml/kg = 4500 mL TBV
4500 mL x 0.15 = 675 mL (max ECV)glg
How do you calculate % yield of deglycerolized RBC’s?
(DRBC wt g x HCT /
RBC wt g x HCT) x 100
How many mL in a pint?
473 mL
Calculate how much blood to drawn in donor less than 110 lbs?
Donor wt (Kg)/ 50 x 450 = (a) vol. to draw a /100 x 14 = (b) amt of anticoagulant 63-b = amt to remove
What is the ration of anticoagulant to WB in CPD and CPDA-1 units?
1.4 to 10 ml
or 14 to 100 ml
Calculate how many units to test to find compatible blood.
of units need / % negative
Calculate how many units will be compatible out of how many tested.
units tested x % negative
Calculate F-VIII concentrate dose.
PV x desired increment
