SBB Last Chance Review
Review for the SBB/BB Exam
February 13-14, 2016
Education and Training Department
1400 La Concha Lane
Houston, Texas 77054-1802
www.giveblood.org
SBB Last Chance Review 2016
Gulf Coast Regional Blood Center, Houston, Texas
A Big Thank You to Our Faculty
Brenda C. Barnes, PhD, MLS(ASCP)CMSBBCM
Clinical Laboratory Science Program, Allen College, Waterloo, IA
Rebecca Dangerfield, MT(ASCP)SBB
American Red Cross, Saint Paul, MN
CM
CM
Kayla Hansen, MLS(ASCP) SBB
University of Minnesota Medical Center Fairview, Minneapolis, MN
Beth Hartwell, MD
Gulf Coast Regional Blood Center, Houston, TX
Tina Ipe, MD, MPH
Houston Methodist Hospital, Houston, TX
Chris Leveque, MD
Houston Methodist Hospital, Houston, TX
Ryan Nobles, MT(ASCP)CMSBBCM
Gulf Coast Regional Blood Center, Houston, TX
Eric Salazar, MD
Houston Methodist Hospital, Houston, TX
Emilie Webb, MLS(ASCP)CMSBBCM
American Red Cross, Madison, WI
Continuing Education Credit
13 P.A.C.E. credit hours approved
Level of Instructions: Intermediate
Gulf Coast Regional Blood Center is approved as a provider of continuing education programs in the
clinical laboratory sciences by the ASCLS P.A.C.E.® Program, California Agency #0001, and Florida Board of
Clinical Laboratory Personnel.
SBB Last Chance Review 2016
Gulf Coast Regional Blood Center, Houston, Texas
February 13, 2016
Saturday Minutes
8.00
20
8:20
50
9:10
9:20
30
9:50
30
10:20
30
10:50
30
11:20
11:50
50
12:40
40
1:20
1:30
15
1:45
50
2:35
40
3:15
3:25
35
4:00
40
4:40
10
30
10
10
Testing tips: SBB/BB exam
Lab math, lab management, QA and safety
Break
K
ABO/Lewis/P1P /I
Rh
Kell, Kidd, Duffy
MNS and other blood groups
Lunch
Special techniques
Positive DAT, adsorption/elution
Break
Polyagglutination
Crossmatch and antibody cases
Genetics/population genetics
Break
Immunology & complement
Adverse effects of transfusion
End Saturday session
Kayla Hansen
Kayla Hansen
HLA, HPA, HNA, & HSCT
Hemostasis and coagulation cases
Break
HDFN & RhIG
Blood collection
Break
TTD testing and re-entry
Cell survival & anemias
Lunch
Blood components and transfusion practice
Hemapheresis
Closing
Eric Salazar, MD
Eric Salazar, MD
Kayla Hansen
Emilie Webb
Emilie Webb
Emilie Webb
Ryan Nobles
Ryan Nobles
Becky Dangerfield
Becky Dangerfield
Brenda Barnes
Brenda Barnes
Brenda Barnes
February 14, 2016
Sunday
8:00
8:40
9:30
9:40
10:10
10:40
10:50
11:30
12:10
12:40
1:30
2:10
40
50
10
30
30
10
40
40
30
50
40
Beth Hartwell, MD
Beth Hartwell, MD
Beth Hartwell, MD
Tina Ipe, MD
Chris Leveque, MD
Chris Leveque, MD
SBB/BB Exam Testing Tips
1
BOC at a Glance
Preparing for the ASCP BOC
SBB/BB Exam
•
ASCP Board of Certification (BOC) fee:
$290 SBB: Specialist in Blood Banking
$240 BB: Technologist in Blood Banking
•
Kayla Hansen, MLS(ASCP)SBBCM
University of Minnesota
Medical Center
Exam Process
•
•
•
•
•
February 13, 2016
Once approved by ASCP, take exam within 3 months
2½ hours, 100-questions, all multiple-choice
One question presented at a time
Computer adaptive exam (CAT), criterion-referenced
Passing 400, maximum score 999
2
Exam Content (%)
BB
SBB
15-20
15-20
GRPS Blood group systems
15-20
15-20
6
IMMU
Immunology
5-10
5-10
5
LO
Laboratory Operations
5-10
15-20
4
PHYS
Physiology/Pathophysiology
5-10
10-15
3
SER
Serologic/Molecular Testing 20-25 20-25
2
BP
Part 1
ASCP BOC exam model
Computer Adaptive Test (CAT)
Blood products
TRNS Transfusion practice
15-20
15-20
SBB
BB
7
1
0
3
Recall
Application
Analysis
Example:
What is the most common
ABO blood group?
Use recalled knowledge
to interpret or apply
written, numeric or
visual data
A patient with sickle cell
disease types R0. What
antibodies can this patient
make?
Apply recalled
knowledge to resolve a
problem and/or to make
a decision
Given discrepant ABO
testing results, select the
next procedures to resolve
the problem.
15
20
25
4
• Computer interactive to individual’s ability, and not
influenced by other test takers
• The first question is of average difficulty (half of test
takers are expected to get right)
CAT tailors questions
to match your ability
Answered correctly: Next question has a
slightly higher level of difficulty and
continues until you answered incorrectly
Answered incorrectly: Next question will
be slightly easier. This way, the test is
tailored to the individual’s ability level
• After a few questions, CAT determines your skill level
and will approximate your final score.
5
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10
Computer-Adaptive Testing (CAT)
Cognitive Skills
What is it?
Recall previously
learned knowledge
5
*SER remains the highest %
Top 5 topics: SER, BP, GRPS, LO, TRNS (LO ↑ for SBB exam)
6
SBB/BB Exam Testing Tips
2
CAT Strategy
• Must answer enough difficult questions correctly to
achieve a score above the a passing score (400). Score
calculated by
– Total number of correct answers
– Difficulty level of all 100 questions
Part 2
• Strategy:
Application to BOC
– Do your best to answer each question correctly. This way, you
will have a exam that has a high level of difficulty (requiring
fewer correct answers to pass)
– Guessing (and coming back to it later at review) will cause
the computer to give you a test with a lower difficulty and
requiring more correct answers to pass
7
Check Your Eligibility
SBB
Documents: Transcripts and Experience
BB
Baccalaureate degree…AND successful
completion of a CAAHEP-accredited
Specialist in Blood Bank Technology
program within the last 5 yrs
MT/MLS(ASCP) certification, AND
a baccalaureate degree from a
regionally accredited
college/university
MT/MLS(ASCP) or BB(ASCP)
certification, AND a baccalaureate
degree…AND 3 years of full time
acceptable experience in a clinical*
laboratory in blood banking… or
educator…within the last 10 years…
Baccalaureate degree… with a
major in biological science or
chemistry … AND 1 year full time
acceptable clinical laboratory*
experience in blood banking…
3
Masters or Doctorate….AND 3 yrs clin…
BS degree…AND completion of BB…
4
Doctorate…AND 2 yrs fellowship in BB…
Master’s or doctorate…AND…
1
2
8
*in the US or Canada or a lab with CMS CLIA certificate of registration…OR JCI, OR accredited
under ISO 15189
• Official transcripts*
– BS degree only, in a sealed envelope
signed by the college/university
– Academic work completed outside of
the U.S. and Canada: must be
evaluated by an evaluation agency
• Experience
Route 1 (CAAHEP SBB Program)
No need to send experience
documentation
*SBB applicants:
Transcript is NOT required
If previously certified as a
MT/MLS or BB on or after
1/1/2000. Must supply your
Certification Number on
your application.
Routes 2, 3, 4
1. Experience documentation forms
2. Letter of authenticity
9
Example form
10
When to Apply
• CAAHEP SBB program
– Processing takes 45 days, so plan ahead
– Students should apply no earlier than four to six weeks
prior to completing the program.
– SBB program official must sign the ‘record release’
– You must finish all program requirement!
• Other Routes -Allow time to obtain the following:
– Transcripts (and evaluation if applicable)
– Experience documentation form
– Letter of authenticity
11
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SBB/BB Exam Testing Tips
3
Application: CAAHEP SBB Program
Must Apply Online
Important: create an account
if you don’t have one.
Information to complete online application include:
• Applicant
– Name* as it appears on driver’s license/state ID
– Personal email address
•
Online screens are selfexplanatory
•
Pay by credit card online (ASCP
will acknowledge your application
within 1 business day)
13
• SBB program
– Name of program (select from drop-down menu)
– Program beginning date and ending date
– Program director: name, phone number and email address
*If the first and last names do not match the valid ID when the applicant
appear at the test center, she/he will not be permitted to take the examination.
Will have to reapply and submit a full application fee.
Using Mail?
14
ASCP Approval Notification
• ASCP will email “Admission Notice” with instructions
• Immediately make an appointment (by phone or
online) at Pearson to reserve your test date
• You will have 3 months to take the exam
• If unable to pay online with a credit card: will get payby-mail instructions after completing the online
application
• If applicable, also send
• Transcripts
• Experience documentation form
• Letter of authenticity
Example of email from ASCP
• Send via regular mail
– Do not FAX
– Do not use Express/ Registered Mail, FedEx, or UPS
15
16
Study References
• ASCP
– Online Practice Tests
– BOC Study Guide
– Examination Content Guidelines
Part 3
• AABB
– Technical Manual – all chapters plus Methods sections
– Standards
How to Study
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SBB/BB Exam Testing Tips
4
Remember the 7 Categories
BB
SBB
15-20
15-20
GRPS Blood group systems
15-20
15-20
IMMU
Immunology
5-10
5-10
LO
Laboratory Operations
5-10
BP
Blood products
Subsections
Routine tests
Examples
AABB standards, compatibility testing,
antibody identification, DAT
15-20
Reagents
AHG, reagent antisera and cells
Application of Special
Tests and Reagents
Enzymes, adsorption, elution, ELISA,
molecular techniques
Leukocytes/platelet
testing
Cytotoxicity, platelet testing, granulocyte
testing, molecular techniques
Quality assurance
Blood samples, reagents, procedures
PHYS
Physiology/Pathophysiology
5-10
10-15
SER
Serology/Molecular Testing 20-25
20-25
TRNS Transfusion practice
15-20
Examination Content Guidelines
Example: Serologic/molecular testing is 20-25% for SBB
exam. What materials are covered?
15-20
0
5
10
15
20
*SER remains the highest %
Top 5 topics: SER, BP, GRPS, LO, TRNS
25
19
20
How to Study: Have a Plan
• Gather and organize resources (reading list,
lectures/notes, previous tests, texts, etc)
• Identify areas that need additional study
• Create a study outline
• Develop a comprehensive study schedule. It may be
better to study a short time every day than to a long
time infrequently
• Practice answering multiple-choice questions
• Allow sufficient time for final review before exam
Part 4
Testing Site
Taking the Exam
After the Exam
21
Day of Exam: Bring ID and Letter
Day Before Exam
• Pack ID and paperwork
• Know directions to the
test site. Do a dry run
and find the room
• Relax
• Get a good night’s
sleep
22
Arrival & Checking in at Exam Site
• Eat a good breakfast/meal
• Arrive at least 30 minutes before test time
• At Pearson’s
Gather these documents:
• ASCP BOC admission letter
• Drivers license (or state
identification card) with photo
and signature. First/Last name
on card must match the
registration at Pearson.
• Can bring non-programmable
calculator
– Show admission letter and ID
– Will take: Signature, photo, palm vein image
• Checklist with rules provided
• These are not allowed in test room (Place into a locker)
– your personal belonging (including watch, cell phone, etc)
• Another palm vein scan before you are seated in the
exam room
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24
SBB/BB Exam Testing Tips
5
Testing site: What’s Provided?
Taking the Exam
•
•
•
•
•
At computer, verify your name and examination category
Directions will pop up: read carefully
When you are ready, click Start. The time will count down.
Questions will appear one at a time
Answer each question the best you can. Select A, B, C or D.
– You may change response within the question
– If unsure of answer, mark it for review
– Press the “ENTER” key or click NEXT. The next question will
then appear
• Proctor can be summoned during test
Antibody
Panels
Dry eraser board
• Computer & seating location assigned
• Monitoring system – audio and video recorded
• 2½ hours, 100-question (90 seconds per question)
25
Taking the Exam
26
Reviewing/Submitting the Exam
• Do your best to select the correct answer, especially
the first third of exam
• Review the exam
– Most people finish the exam in 2 hours
– If you have 30 minutes left, review all questions
– If less than 30 minutes left, review only marked questions
– Less difficult questions will require your to answer more
questions correctly to pass
– Score is combination of total number of correct answers and
difficulty of correct answers
• Changing answers
• What if you don’t know the answer?
– When you guess and enter the wrong answer, CAT will adjust
levels of questions that may be all wrong for your ability level
– Do your best and give the most educated response
– Mark the question for review
– Change your answer only if you are sure
– When you change an answer, you have 66% of getting it right.
• Submit the exam
– A verify screen will appear – click YES
– The preliminary Pass or Fail message will show
27
Did Not Pass?
Score Report
Score in 4 business days
• ASCP will email you to login to get the score report
• Report will show the scaled score (how many points)
• Print the report – it is the only document that contains your
certification number. Otherwise, will have to pay $15 to get
the report.
• Individual scores from each category provided to:
– SBB program officials
– Those who failed exam -provide the areas that need concentration
Certificate
• Mailed in 3-6 weeks
• Valid for 3 years
• ASCP will send by email
– Show scaled scores in each subtest
– Instructions on how to reapply
– May not retake exam within the same three month period
• Reapplication documents/fee
– ASCP keeps your original application and the supporting
documentation for 5 years
– Can take 5 times for each eligibility route
– Must pay application fee each time
• Re-apply: takes about 2 weeks for ASCP approval
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30
SBB/BB Exam Testing Tips
6
BOC Pass Rate (%)
Questions for ASCP BOC
100
90
86
80
84
84
86
74
70
58
61
61
57
84
77
79
68
67
60
50
86
53
54
63
54
52
46
47
40
1st time CAAHEP
SBB pass (63%)
BB pass (64%)
SBB total pass (47%)
ASCP BOC
800-267-2727
[email protected]
30
20
10
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
0
31
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32
Lab Math &
Lab Operations
1
Objectives
Lab Math &
Lab Operations
1.
2.
3.
Kayla Hansen, MLS(ASCP)SBBCM
4.
University of Minnesota
Medical Center
5.
Perform basic lab math calculations.
Calculate FTE and compare methods for cost
savings.
Differentiate quality control, quality assurance, and
quality management.
Describe the basic elements of a quality program.
Discuss the elements of a safety program.
February 13, 2016
2
BOC SBB Exam: Lab Ops
A.
B.
C.
D.
E.
F.
Development and Evaluation of New Technology
Safety
Training and Education
Administration and Management (SBB exam only)
Quality Assurance
Laboratory Mathematics
Part 1
The Basics
Accuracy & Precision
This presentation will focus on:
• Lab math and budgeting
• QA and safety
3
Mean, Median and Mode
Accuracy & Precision
Mean – numerical average
Median – middle data point
Mode – most frequent
74
78
79
79
Middle data points
82
82
84
92



4
Accuracy:
Precision:
The degree that data
agrees with the ‘true value”
(how close to or on the mean)
How closely repeated
measurements of a sample
agree with each other
Mean = 81.3
Median* =(79+82)/2 = 80.5
Mode = 79, 82
* Median: For even number of
data, find the middle pair and
get the average
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SBB Last Chance Review
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6
Lab Math &
Lab Operations
2
Dilution
Basic Conversion
1 L = 1000 mL, 10 dL
1 Kg = 2.2 lb
1 in = 2.54 cm
(V1)(C1) = (V2)(C2)

How many mL
are in 0.13 L?

How many dL
are in 4000 mL?

Calculate the dilution needed to make 100 mL 6%
albumin from 22% albumin.

(V1)(22%) = (100 mL)(6%)

V1 = 600/22 = 27.3 mL

Dilution: mix 27.3 mL 22% albumin + 72.7 mL saline
7
RhIG

8
Exchange Transfusion
Fetal maternal hemorrhage (FMH) shows 2.5% fetal
cells. How many vials of RhIG should be given?
Assumption: A woman’s BV is 5000 mL

An exchange transfusion is ordered for red cells with
a 50% hct. The RBC unit you have is 325 mL with a
70% hct.
1 RhIG takes care of 30 mL fetal bleed (15 mL red cells)
(V1)(C1) = (V2)(C2)

2.5% = 0.025

(325 mL)(0.7) = (V2)(0.5)

FMH = (0.025)(5000 mL) = 125 mL

227.5 = (V2)(0.5)

RhIG needed = 125 mL/ 30 mL/vial = 4.2 = 4

V2 = 227.5/0.5 = 455

RhIG = 4 + 1* = 5 vials

Dilute the 325-mL RBCs to 455 mL with plasma


*AABB Technical Manual recommends adding 1 vial
455 – 325 =130
Add 130 mL plasma to the RBCs unit
9
10
Antigen Screening

Two RBCs are ordered for a patient with anti-E, -K
and -Fya. How many units should be screened?




Ag
% Pos
% Neg
E
30
70
K
9
91
Fya
66
34
Rh, Kell and Duffy are
independent systems. For
independent events, multiply.
Part 2
Donor Collections and
Components
Multiply the antigen-negative
(.70)(.91)(.34) = .22 (= 22%)
22/100 = 2/X
x = 2/.2 = 9 units to be screened
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SBB Last Chance Review
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12
Lab Math &
Lab Operations
3
Donor Blood Collection
Blood Volume
Blood volume* = (kg)(75 mL/kg)
1 kg = 2.2 lb
Blood volume collected* = 10.5 mL/kg maximum
What is the maximum volume of donor blood that
can be collected in a 500-mL bag for a 110 lb
donor?

A patient weighing 190
lbs lost 1500 mL of
blood. What percentage
of his total blood volume
was lost?

Answer
190 lb = 86 kg
2.2 lb/kg
BV = (86 kg)(75 mL/kg)
= 6450 mL

110 lb/2.2 lb per kg = 50 kg

(50 kg)(10.5 mL/kg) = 525 mL maximum blood collected
% blood lost = volume lost / BV
= 1500 / 6450 mL
= 23%
*AABB Technical Manual uses 75 mL/Kg
13
Component Yield
Half Life

Total plt = (Plt /uL)(103 uL/mL)(vol in unit)

*AABB Standards: 10.5 mL/kg
525 mL includes blood in collection bag and test tubes for testing 14
A 500-mL whole blood (WB) unit has a platelet (plt)
count of 228x103/μL. The Platelet Concentrate (PC)
made has 61 mL with 1300x103/uL plts. What is the
plt yield?

PC = (1300x103 /uL)(103 uL/mL)(61mL) = 0.79x1011

WB = (228x103/uL)(103 uL/mL)(500mL) = 1.14x1011

Yield = PC = 0.79 = 69%*
WB 1.14
*69% is the average yield in a Platelet unit
IgG half life = 23-25 days
Kg body wt = 190/2.2 = 86.4 kg
BV = (86.4 kg)(75 mL/kg) = 6480 mL

PV = (6480 mL)(1- .46) = 3499 mL
64 /23 days = 3 half life days
% IgG remain
100
50
Half-life
46
69
25
12.5
2
3
1
CRYO = (PV)(Factor VIII increment)/80 IU per bag
Severe hemophilia: assume 0% Factor VIII


A severe hemophiliac is scheduled for surgery
tomorrow. His physician wants to increase his
Factor VIII level to 75% before the procedure. His
hct is 40% and plasma volume is 2500 mL.
Factor VIII concentrate is totally out of stock*. How
many units cryoprecipitate should be given?

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Days
0
23
Cryo Dosing
A blood donor weighs 190 lbs. His hct is 46%.
What is his blood volume and plasma volume?

May 1 to July 4 is 64 days

16
BV (Blood volume) = 75 mL/kg
PV (Plasma volume) = BV(1-hct)


15
Blood Volume / Plasma Volume

A tech received a gamma globulin shot following a
needle stick on May 1. What percent of IgG remains
by July 4?
(2500 mL)(.75 – 0)/ 80 = 23 bags
* Cryo is used primarily to correct fibrinogen deficiency
18
Lab Math &
Lab Operations
4
Corrected Count Increment (CCI)
CCI =(Plt CI)(BSA)
Plt (x1011)

Plasma Exchange
CI= count increment
BV (Blood volume) = 75 mL/kg
PV (Plasma volume) = BV(1-hct)
Review the following data and determine if the patient has
an adequate response to the platelet transfusion.

Patient body surface area: 2 m2
Platelets transfused: 325 mL; platelet count of 1.8x10 6/μL
Pretransfusion platelet count: 11,000/μL
Posttransfusion platelet count: 37,000/μL

Total Plt infused = (325 mL)(1.8x106/μL)(103 μL/mL) = 5.85 x 1011






Count increment = 37,000-11,000 = 26,000/μL
CCI = (26,000)(2) = 8,889 = Yes, adequate response
5.85
Successful >7500 (10 min-1hr posttransfusion)
Refractory <7500 in two or more transfusions
A 70-kg man has a 40% hct. What volume of
plasma is needed for a one-volume plasma
exchange?

BV = (70 kg)(75 mL/kg) = 5250 mL

PV = (5250 mL)(0.60) = 3150 mL

One volume exchange = 3150 mL

If 1-1/2 volume exchange: (1.5)(3150) = 4725 mL
19
20
Hardy-Weinberg Equilibrium

3162 people were tested with anti-J, and 2403
tested positive. Assume J and j are allelic genes.
Find:
Part 3
Hardy-Weinberg

% J positive

Gene frequencies of J and j

% homozygous for J

% heterozygous for J
21
Hardy-Weinberg Equilibrium


Hardy-Weinberg Equilibrium
76% tested J positive (2403/3162 = 76%)
24% tested J negative
p2 + 2pq + q2 =1
p+
Let p = J, and q = j
p + q =1
(p + q)2 =1
p2 + 2pq + q2 =1
p+
Tested
positive
with anti-J
= 76%
22
q2 = .24
q = .49
p + q =1
q = .49
p = .51
p2 + 2pq + q2 =1
(.51)2 + 2(.51)(.49) + (.49)2 = 1
.26 + .50
+ .24 = 1
Homozygous Heterozygous Homozygous
p
pq
q
pTested
negative
with anti-J
= 24%
Note:
After solving for p and q,
always plug the numbers
back into the binomial
equation and check that
all numbers add to 1.
76% p+
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SBB Last Chance Review
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p-
q2 = .24
q = .49
p = .51
24
Lab Math &
Lab Operations
5
HLA Relative Risk (RR)

Part 4:
Relative Risk
Sensitivity and Specificity
G-force
Of the 300 individuals with a certain disease, 250 share a
common HLA antigen. Of the control (no disease) group of
200 people, only 10 have the HLA antigen. What is the
Relative Risk that the HLA antigen is associated with this
disease?



What do we know?
300 have disease, 250 have HLA antigen (50 no HLA)
200 normal control, 10 have HLA antigen (190 no HLA)
RR*=(patients with HLA ag)(controls without HLA ag)
(controls with HLA ag)(patients without HLA ag)
RR = (250)(190) = 95
(10)(50)
*Note: HLA RR calculation conventionally
uses OR (odds ratio): ad/bc
25
Relative Centrifugal Force (RCF)
RR – Visualize It!



26
What do we know?
300 have disease, 250 have HLA
200 normal (no disease), 10 have HLA

Dis+ DisHLA+ 250 10
HLA-
Dis+ DisHLA+ 250 10
HLA- 50 190
300
300
200
Calculate the relative centrifugal force (RCF or g)
of a centrifuge operating at 3600 rpm with a
radius of 3 inches (7.62 cm)
RCF = (28.38) (r) (rpm/1000)2
200

RR= a (patients with HLA ag) d (controls without HLA ag)
b (controls with HLA ag) c (patients without HLA ag)
Test+
Test-
Dis+ Disa b
c d
(10)(50)
27
RCF = (28.38) (r) (rpm/1000)2
A new test is developed to diagnose an infectious disease.
 Test group: of the1000 patients with the infection, 995 tested
positive.
 Control group: 1000 people denied risk factors for the
infection, and 998 tested negative.
First construct a table and plug in what we know:
r = radius (inches)
Disease +
Test+
5000 = (28.38)(10)(X/1000)2

5000/283.8 = (X/1000)2

17.62 = X2/10002

(17.62)(106) = X2

X = 17.62x106
28
Sensitivity and Specificity
What is the rpm to be set if the SOP for making
blood components states to do a heavy spin at
5000 g for 6 minutes? The radius is 10 inches.

r = radius (cm)
RCF = (11.17)(7.62)(3600/1000)2 =1103
RR= (250)(190) = 95
Relative Centrifugal Force (RCF)

RCF = (11.17) (r) (rpm/1000)2

r = radius (inches)
RCF = (28.38)(3)(3600/1000)2 = 1103
Test-
Total
(FN)
1000
Disease -
(TP)
(FP)
998
(TP+FN) 1000
(TN)
TP = true positive
TN = true negative
FP = false positive
FN = false negative
(FP+TN )
Sensitivity = TP/(TP+FN) = 995/(995+5) = .995 (99.5%)
Specificity = TN/(FP+TN) = 998/(2+998) = .998 (99.8%)
= 4198 rpm
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995
30
Lab Math &
Lab Operations
6
Staffing/Budgeting: FTE
Calculate the FTE given the following data.
Part 5
Staffing & Budgeting
Vacation
3 weeks
Sick leave
5 days
Holidays
10 days
CE days
5 days
Productivity
80%
Annual test workload
1,250,000 min/yr
31
1 Add total time off
FTE Formula
FTEs =
32
Annual test workload (min/yr)
Annual workload (min/yr)
Tips:
1. Annual test workload and productivity are provided.
2. Determine the actual time worked per person
- Deduct time off (vacation, CE time, etc)
- Factor in the productivity
3. Convert all units to min/yr
Vacation: 15 days (3 wk) Total time off = 35 days
Sick leave: 5 days
= 7 weeks
Holidays: 10 days
CE days: 5 days
2 Subtract time off from Workload time =
52 weeks in a year
52 weeks –7 weeks
Workload time = 45 weeks/yr
3 Calculate workload
(hrs/year)
(45 weeks/year) x
(40 hrs/weeks)
Annual Workload = 1,800 hrs/yr
4 Factor in the
productivity (min/hr)
(80% productivity) x
(60 min/hr)
Actual work time = 48 min/hr
5 Calculate workload
(min/yr)
(Hours worked/yr) x
(productivity)
(1,800 hrs/yr )(48 min/hr ) =
86,400 min/yr
FTEs = Annual test workload (min/yr)
Annual workload (min/yr)
Given: Annual test workload
1,250,000 min/yr
FTEs = 1,250,000 min/yr = 14.5
86,400 min/yr
33
Staffing/Budgeting: Compare Cost
Staffing/Budgeting: Compare Cost
Method A
Continuing FTE question above…determine which
method (A or B) is more cost effective.
Salary $45,000/year
Benefits = 20%
Test volume = 800/month
Workload unit (min)
Cost per test ($)
Method A
30
7.00
#Test /yr
(800/mon)(12 mon/yr) =
Workload units
(9,600 test/yr)(30 min/test) = 288,000 min/yr
9,600 tests/yr
FTE
288,000 min/yr =
*86,400 min/yr
3.33 FTEs
#Test /yr
(800/mon)(12 mon/yr) =
9,600
Workload units
(9,600 test/yr)(20 min/test) = 192,000 min/yr
FTE
192,000 min/yr =
*86,400 min/yr
Method B
Method B
20
9.00
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2.22 FTEs
*86,400 min/yr is the annual workload from the previous question
36
Lab Math &
Lab Operations
7
cGMP
Current Good Manufacturing Practices (cGMP):
Minimum requirements in 21CFR to ensure the
safety, purity, potency, and identity
of blood products and services.
Part 6
QA, QC, cGMP
AABB QSEs
37
38
QSE 1: Organization
Executive management
& Medial Director
AABB QSEs
Customer
focus
10 sections regardless of
the Standards.
Quality
system
Communication
of concerns
Policies, process &
procedures
Emergency
preparedness
39
QSE 2: Resources: Training


40
QSE 2: Resources: Competency
Required training

Assessment of employees who perform testing

cGMP for manufacturing of blood and its components.

Semiannually during the 1st year

Safety training

Annually thereafter

Job-specific training

Use the learning domain to get desired outcome

Example: training a new hire to do hepatitis screening test,
best to use the psychomotor domain - have the employee
actually perform the test.
Competency and training program includes:

Schedule of assessments

Defined minimal acceptable performance

Remedial measures
Competency
Measures an employee’s ability to perform tasks
according to procedures.
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Lab Math &
Lab Operations
8
QSE 3: Equipment



QSE 3: Equipment
Maintain a list of qualified, critical equipment
Assign unique ID to track all equipment and
software
Calibrate according to schedule
Installation
Qualification
IQ
Operational
Qualification
OQ Tests functional elements and insures that the system
will meet all defined user requirements under all
anticipated conditions of manufacturing. Include a
condition(s) encompassing upper and lower operating
limits (worst case conditions.)
Performance
Qualification
PQ Manufacturing process works consistently under normal
operating conditions.
Calibration:
Calibration - the act of checking or adjusting (by comparison with a
standard) the accuracy of a measuring instrument.
Validation:
The documented act of proving that procedure, process, equipment,
material, activity or system, actually leads to the expected results .
Equipment/system has been installed correctly to the
manufacturer’s specifications.
43
QSE 4: Supplier and Customer Issues
QSE 5: Process Control
Supplier Qualification
An evaluation method defined to ensure that materials or
services received from supplier meets the facility’s specification.



44

Supplier qualification
Agreements maintained and reviewed
Incoming receipt, inspection and testing
Policies and validated processes and procedures
that ensure the quality of blood, blood components,
tissues, derivatives and services. Included are:
1.
Change control of policies, processes or procedures
2.
Proficiency testing program
3.
Quality control
4.
Use of materials according to manufacturer’s directions
5.
Sterility- bacterial contamination
6.
Identification and traceability (includes labeling)
7.
Inspection
8.
Handling, storage and transportation
45
QSE 6: Documents & Records
Document
Records
Written or electronically
generated information or
work instructions.
Information captured in
writing or electronically that
provides evidence of
activities performed.
46
QSE 6: Documents & Records
Policies
A documented general principle that guides
present and future directions.
Procedures
A documented step-by-step work instructions
usually performed by one person.
• SOPs
• Forms
• Labels
Process
A set of related tasks and activities that
accomplish a goal.
47
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“What to do”
“How to do”
“How it
happens”
48
Lab Math &
Lab Operations
9
QSE 7: Deviations, Nonconformances
and Adverse Event
QSE 8: Assessments
Assessments
• Internal
• External
Nonconformance
Failure to meet requirements.
Blood Utilization
Peer review of transfusion practices to ensure the effective use
of limited blood resources
Blood Bank facilities must report:
 Biologic product deviations (BPD) to FDA. This
is regardless of facility’s FDA registration or
licensure.
 Fatalities to FDA Center for Biologics, Evaluation
and Research (CBER) within 7 days of event

Example: Transfusion service reviews:

Blood component ordering practices

Distribution, handling, use and administration of blood
components

Transfusion reactions
49
QSE 9: Process Improvement
50
QSE 10: Facilities and Safety

Corrective
action
Eliminate cause of existing
deviation
Preventive
Action
Reduce potential for future
deviation
Quality
Monitoring
Evaluate data for trends that
may indicate the need for
corrective/preventive action


Safe environment - Facilities and workflow
Biological, chemical and radiation safety
Discard of components, tissues, and derivatives
51
52
Biosafety Levels
2. Moderate
hazard
4. High risk for
lifethreatening
disease
See the next document for
additional lab math problems
Most blood
bank labs
1. Minimal
hazard
3. Potential
exposure to
lethal disease
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Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 1 of 12
Quick Formulas & References
Mean
Median
Mode
Mole (M)
Percent solutions
Concentration
Pound-kilogram
conversion
Inch/cm
conversion
Liter
Metric
conversion
Blood volume*
(BV)
Mean = Numerical average
Median = Middle value of a list: 50% of the data are above and 50% are below
Mode = The most common (frequent) value in a list
1 M = One mole of solute in one liter solution
% solution = Grams of solute in 100 mL of solution
(V1)(C1) = (V2)(C 2)
V= volume; C = concentration
1 kg = 2.2 lbs
1 lb = 0.45 kg
1 in = 2.54 cm
1 cm = 0.39 in
Liter (L) is the standard unit of volume in the metric system (for volume)
1 milliliter (mL) = 0.001 L
1 centiliter (cL) = 0.01 L
1 deciliter (dL) = 0.1 L
Adult: 70-75 mL/kg*
* Approximate volume used for calculation
Term infant: 80-85 mL/kg*
Premature infant: 100 mL/kg*
Plasma volume
(PV)
PV = BV (1-hct)
RBCs dosing
Red blood cells decrease at the rate of 1% per day
1 mL red cells = 1 mg iron
One unit of RBCs will raise the hb by 1 g/dL (3% hct)
One unit of random platelets will raise the platelet count by 5,000 to 10,000/uL
Platelet dosing
Platelet
transfusion
Corrected Count
Increment (CCI)
Plasma dosing
Half-life
Factor VIII dosing
Clotting factor
concentrate
Factor VIII dosing
CRYO*
CCI = (Post - Pre platelet count)(body surface area)
11
Unit content (x10 )
Successful transfusion: CCI ≥7500
Refractory patient: two or more transfusions with CCI <7500
One unit of plasma (e.g., FFP, PF24) will raise all clotting factors by approximately 10%
1% Factor activity = 1 IU/mL
Half- life of Factor VIII: 8-12 hours
Half-life of IgG: 23-25 days
Severe: <1% Factor VIII
Hemostasis requires >50% Factor
VIIII
Factor VIII dose = (PV) (desired increase in Factor VIII)
PV in mL
Factor VIII in IU
AABB Standards QC: 1 CRYO unit must have 80 IU Factor VIII and 150 IU fibrinogen
For calculation purposes: assume 1 CRYO has 80 IU Factor VIII
# CRYO units = (PV)(desired Factor VIII increment)
80 IU/bag
Fibrinogen dosing
CRYO
% CRYO yield
*Note: CRYO is used primarily for correcting fibrinogen deficiency. It used for its Factor
VIII only when factor concentrates are not available.
For calculation purposes: assume 1 CRYO has an average 250 mg fibrinogen
# CRYO units = PV (dL) x Desired fibrinogen increment
(mg/dL)
250 mg/bag
This calculation is used for QC of CRYO preparation.
CRYO yield = (Factor VIII/mL)(volume of CRYO)
(Factor VIII/mL)(volume of FFP)
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 2 of 12
Quick Formulas & References (Continued)
Blood donation
volume
IUT (Intrauterine
transfusion)
Exchange
transfusion Reconstituting RBCs
RhIG dosing in
Fetomaternal
hemorrhage (FMH)
Maximum volume of blood drawn: 10.5 mL/kg
450-mL collection bag has 63 mL anticoagulant; range of draw +/- 10% (405-495 mL)
500-mL collection bag has 70 mL anticoagulant; range of draw +/- 10% (450-550 mL)
Red Blood Cells Low Volume
 When only 300-404 mL whole blood is in a 450-mL collection bag
 When only 333-449 mL whole blood is in a 500-mL collection bag
 Unit must be labeled “Red Blood Cells Low Volume.” No other components
(plasma, platelets, etc.) can be made.
(Fetus wt in g)(0.14 mL/g)(hct increment)
Hct of RBC unit
(Volume1)(hct1) = Volume2)(hct2)
Same as (V1 )(C1 ) = (V2 )(C2)
FMH= (# fetal cells)(5000*)
# maternal cells
*5000 mL is the assumed maternal
blood volume
RhIG needed = (Volume of FMH)
30 mL/vial
One RhIG protects against 30 mL of
whole blood fetal bleed (15 mL red cells)
AABB Technical Manual recommends adding one vial
MLC Relative
Response (RR) for
HLA disparity
% Relative Response = RDx – RRx
RCx – RRx
RR 40-60% = haploidentity
RR <15-20% = HLA-D locus identity
Cpm = count/min; x = irradiated
RCx = recipient stimulate (cpm)
RDx = recipient stimulated with donor cells (cpm)
RRx = recipient autocontrol (cpm)
Relative risk: HLA
disease association
RR = (patients with HLA antigen) (controls without HLA antigen)
(controls with HLA antigen) (patients without HLA antigen)
Sensitivity and
Specificity
Sensitivity = True Positives / (True Positives + False Negatives)
Specificity = True Negatives / (True Negatives + False Positives)
FTEs
FTEs =
Relative centrifugal
force (RCF) or (g)
Antigen screening
Hardy-Weinberg
Equation
Annual test workload
(Annual workload hrs)(productivity)
Note conversion: units should
be in minutes/year
Annual test workload = (# tests/yr)(unit value) = # tests (min/yr)
Annual workload (hrs/yr) = (46 wks/yr)(40 hr/wk) = 1840 hr/yr (assuming 6 wks time off)
Productivity = (.75)(60 min/hr) = 45 min/hr (assume 75% productivity)
2 formulas:
2
RCF = (28.38)( r)(rpm/1000) where r = radius in inches
2
-5
2
RCF = (0.00001118)( r)(rpm) or RCF = (1.118x10 )(r)(rpm) where r = radius in cm
# compatible = # desired
100
X
2
2
2
2-allele system: p + q = 1; (p + q) = 1; p + 2pq + q = 1
2
2
2
2
3-allele system: p + q + r = 1; (p + q + r) = 1; p + q + r + 2pq +2pr + 2rq = 1
References:
1. AABB Technical Manual, current edition
2. Fridey JL, Kasprisin CA, Chambers LA, Rudmann SV. Numbers for blood bankers. Bethesda, MD:
American Association of Blood Banks, 1995.
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 3 of 12
Sample Calculations
Mean, mode, and standard deviation
1
Problem
For the following set of numbers,
calculate the mean, median, and mode.
Formula
Mean=average
Median= at 50%
Mode=most often
77
77
78
79
80
80
81
89
92
Mean = 81.44
Median = 80
Mode = 77, 80
Median: If list has an even
number of data, take the
middle 2 and average them.
Metric conversion
-
1
How many milliliters are in a
deciliter?
1 L = 1000 mL
1 dL = 0.1 L
1 dL = 10 ¹ L = 0.1 L = 100 mL
2
How many dL are in 4000 mL?
1 L = 1000 mL
1 dL = 0.1 L
(4000 mL)(1 L/1000 mL)(1 dL/.1 L) = 40 dL
(V1 )(C1 ) = (V2 )(C2)
(X)(22%) = (100 mL)(6%)
X = (100)(6)/ 22
X = 27.3 mL
Mix 27.3 mL 22% albumin + 72.7 saline
1% = 1 g/100 mL
.9% = .9 g/100 mL
Dilution and solutions
1
How would you make 100 mL of 6%
albumin from 22% albumin?
2
3
How many grams of NaCl are needed to
prepare 1 liter of 0.9% NaCl?
How many grams of NaCl are needed to
prepare 500 mL of 0.3% NaCl
(hypotonic saline)?
1L = 1000 mL
1% = 1 g/100 mL
1% = 1 g/100 mL
.9 g
= X
100 mL 1000 mL
1% = 1 g/100 mL
0.3% = 0.3 g/100 mL
0.3 g = X
100 mL 500 mL
4
A total of 100 donor units are to be
screened for a high-prevalence antigen.
The typing antisera used for this
screening can be diluted 1:4.
1. How many drops of antisera are
needed?
2. If the antisera costs $1.20 per drop,
what is the total cost of this screening
test?
X = 9 g NaCl
X = 1.5 g NaCl
(100)(¼) = 25 drops antisera needed
(25)($1.20) = $30.00
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 4 of 12
Sample Calculations
Pound and kilogram
1
2
A patient weighs 110 lb.
What is the weight in kg?
A patient weighs 187 lb.
What is the weight in kg?
Kg = lb/2.2
Kg = 110/2.2 = 50 kg
Kg = lb/2.2
Kg = 187/2.2 = 85 kg
Formula
1 kg = 2.2 lb
General minimum
weight to donate
WB = 50 kg
AABB STD permits
10.5 mL/kg
Collection range =
500 mL +/- 10%
Calculation
Kg = 120/2.2 = 54.5 kg
Yes, the donor can donate.
450mL +/- 10%
(450)(0.10) = 45 mL
405 - 495 mL blood can be collected into
450-mL collection bags
100 lb/2.2 = 45.5 kg
Volume of blood that can be removed:
(45.5 kg)(10.5 mL/kg) = 478 mL
Blood Collections
1
Problem
A donor weighs 120 lb.
What is the weight in kilogram (kg)?
Can this donor donate whole blood
(WB)?
2
What is the range of whole blood (in
mL) that can be collected using a 500mL collection bag?
3
What is the range of whole blood that
can be collected using a 450-mL
collection bags?
Autologous Donation
An autologous whole blood is to be
collected from a 100-lb person. A 500mL collection bag will be used.
4
What volume of blood can be removed
from this individual?
5
If excess anticoagulant is to be removed
from the main collection bag,
approximately how much should be
removed?
Autologous Donation
An autologous whole blood is to be
collected from a 60-lb child. A 500-mL
collection bag will be used.
What volume of blood can be collected
from this individual?
If excess anticoagulant is to be removed
from the main collection bag,
approximately how much should be
removed?
What we know:
10.5 mL/kg
500-mL collection
bag has 70 mL
anticoagulant
(500)(0.10) = 50 mL
450 - 550 mL blood can be collected into
500-mL collection bags
A collection is considered low volume when
only 333-449 mL whole blood is collected
into a 500-mL collection bag.
In this case, there is no need to remove any
anticoagulant.
What we know:
10.5 mL/kg
500-mL collection
bag has 70 mL
anticoagulant.
60 lb/2.2 = 27.27 kg
Volume of blood that can be removed:
(27.27 kg)(10.5 mL/kg) = 286 mL
Note: 10.5 mL/kg represents not only the
blood that goes into the collection bag, but
includes blood to be placed in tubes for
testing and blood in the collection line, which
is approximately 50 mL. The volume that will
actually go into the collection bag is 286-50
= 236 mL, which is below the low-volume
collection of 333-449 mL.
70 mL = X = 33 mL anticoagulant*
500 mL 236 mL
70 mL – 33 mL = 37 mL should be removed
th
* Formula: 15 ed AABB Technical Manual
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 5 of 12
Sample Calculations
Blood volume and plasma volume
1
2
3
Problem
A patient weighs 150 lb. What is the total
blood volume (BV)?
A patient weighs 187 lb. His hct is 45%.
a. What is the total blood volume (BV)?
b. What is the red cell volume?
c. What is the plasma volume (PV)?
A patient who weighs 180 lbs. lost an
estimated 1500 mL of blood. What is %
blood loss?
Formula*
Kg = lb/2.2
BV = 75 mL/kg
Kg = lb/2.2
BV = 75 mL/kg
Red cell = (BV)(hct)
PV = (BV)(1-hct)
Kg = lb/2.2
BV = 75 mL/kg
% lost = Volume lost
Total BV
Calculation
Kg = 150/2.2 = 68.2
BV = (68.2 kg)(75 mL/kg) =5114 mL
Kg = 187/2.2 = 85
BV = (75 mL/kg)(85 kg) = 6375 mL
Red cell = (6375)(.45) = 2869 mL
PV = (6375)(1- .45) = 3506 mL
Kg = 180 /2.2 = 81.8 kg
BV =(81.8 kg)(75 mL/kg) = 6136 mL
% lost = 1500/6136 = 25%
*Note: 75 mL/kg is the approximate blood volume used for these examples
RBCs and Platelet Dosing
1
2
3
Problem
A patient has a pretransfusion
hematocrit of 25%. What is the
expected hemoglobin after the
transfusion of 2 units of RBCs?
Platelet are ordered for a patient with a
platelet count of 15,000. The target is to
raise his count to 50,000 for surgery.
How many units of platelets should be
transfused?
A request is received for a 25-lb child to
raise his hct from 21% to 36%. The unit
you have on hand has an hct of 68%.
How much blood is required?
Formula*
1 unit RBCs raises
the hct by 3% or the
hb by 1 g.
Calculation
Patient’s starting hct = 25% or 8 g
After 1 RBCs = 28% or 9 g
After 2 RBCs = 31% or 10 g
1 random platelet
unit will raise the
platelet count by
5,000-10,000.
Increment needed = 35,000 plts
35,000/5,000 = 7 units
35,000/10,000 = 3.5 units
4-7 platelets should be transfused.
Kg = lb/2.2
BV = 75 mL/kg
(V1 )(C1 ) = (V2 )(C2)
Kg = 25 lb/2.2 = 11.4 kg
BV = 11.4 kg)(75 mL/kg) = 852 mL
Hct increment = 36-21 = 15%
(V1 )(C1 ) = (V2 )(C2)
(852 mL)(15%) = (X)(68%)
X = 187 mL
Total plt infused =
= (267 mL)(1.5x106/uL)(103uL/mL) = 4x1011 plts
Count increment = 25000-5000 = 20000/uL
CCI = (20000)(2) = 10,000
4
Yes, the response to the platelet transfusion
is adequate.
A patient was transfused one apheresis CCI =(Plt CI)(BSA)
platelets containing 267 mL with a
Plt (x1011)
6
concentration of 1.5x10 /uL. His preCI= count increment
transfusion platelet count was 5000/uL
and the post 25,000/uL. His body
Successful: ≥7500
2
surface area is 2 m . Did the patient
Refractory: <7500
have an adequate response to the
in two or more
platelet transfusion?
transfusions
*Note: 75 mL/kg is the approximate blood volume used for these examples
4
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 6 of 12
Sample Calculations
CRYO dosing
1
2
Problem
A patient’s Factor VIII level is currently
75%. How long will it take for the level to
fall below 10%?
Formula*
½ life Factor VIII =
8 hours
A 70-kg male with a hct of 40% has less
than 1% FVIII. The doctor wishes to
raise the FVIII to 99% for surgery. How
much FVIII concentrate should be
given?
1% = 1 IU/mL
1 kg = 75 mL/kg
FVIII increment =
desired - current
Note: severe FVIII deficiency is <1%
Calculation
Time (hrs) Factor VIII level
0
75%
8
37.5%
16
19%
24
<10%
Answer = 24 hours
BV= (70 kg)(75 mL/kg) = 5250 mL
PV =(BV)(1-hct) = (5250)(0.6) = 3150 mL
FVIII =(PV)(increment FVIII)
= (3150)(99-1)
=(3150 mL)(0.98 IU/mL)
= 3087 IU FVIII
Repeat dose to ensure hemostasis >50%
FVIII activity
For the patient above, Factor
concentrate is out of stock; only CRYO
is available. How many bags of CRYO
are needed?
1 CRYO = 80 IU FVIII
4
The level of Factor VIII in the above
patient was raised to 99%. How long
will it take for the level to fall below 10%
again?
The half-life of
Factor VIII is 8-12
hours.
Assuming 8 hours half-life:
Current level: 99%
8 hours later: 49.5%
16 hours later: 24.8%
24 hours later: 12.4%
32 hours later: 6.2%
Answer: the level will fall below 10% in
approximately 32 hours.
5
A patient has 6500 mL total blood
volume and fibrinogen of 82 mg/dL.
How many total grams of fibrinogen
does this patient have?
1 dL = 100 mL
1 g = 1000 mg
BV = (6500 mL)(1 dL/100 mL) = 65 dL
Fibrinogen =(82 mg/dL)(65 dL) =5330 mg
(5330 mg)(1 g/1000 mg) = 5.33 g
6
Cryoprecipitate is ordered for a 130-lb
patient with a hematocrit of 35%. The
target is to raise her fibrinogen from 10
mg/dL to 100 mg/dL. How many bags of
cryoprecipitate should be transfused?
1 dL = 100 mL
1 CRYO = 250 mg
(use for calculation)
130 lb/2.2 = 59 kg
BV = (59 kg)(75 mL/kg) = 4431 mL
PV = (4431)(1- .35) =2880 mL = 28.8 dL
Fibrinogen increment =(100-10)= 90 mg/dL
Fibrinogen need =(28.8 dL)(90 mg/dL)= 2592 mg
#CRYO = 2592 mg/250 mg per bag = 11 units
3
(PV)(increment)
80 IU /CRYO
= (3150)(.98) = 38 bags of CRYO
80
*Note: 75 mL/kg is the approximate blood volume used for these examples
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 7 of 12
Sample Calculations
Plasma Exchange
1
An 84-kg man with a 45% hematocrit is
undergoing a plasma exchange.
1. What volume of plasma is needed
for a one-volume plasma
exchange?
2. What volume is needed for 1.5
volume exchange?
1 kg = 75 mL blood
PV = 1- hct
BV = (84 kg)(75 mL) = 6300 mL
PV = BV(1- hct ) = (6300)(0.55) = 3465 mL
1 volume exchange = 3465 mL
1.5 vol exchange* = (1.5)(3465) = 5198 mL
*Plasmapheresis is usually limited to 1 or
1.5 plasma volumes
(.63)(250 mg/dL) = 158 mg/dL removed;
92 mg/dL remains
2
For the above patient, 250 mg/dL
One exchange will
pathologic substance needs to be
remove 63% (2/3)
removed in the plasma exchange. What of a substance (if
is the expected concentration left in the
only intravascular
plasma after a one volume exchange
distribution)
procedure?
*Note: 75 mL/kg is the approximate blood volume used for these examples
IUT, FMH and Exchange Transfusion
Problem
1
An IUT is ordered to raise the hct of a
1100-g fetus from 20% to 45%. The
RBC unit has a hct of 70%. How much
blood is needed for the IUT?
Formula
BV for IUT =
0.14 mL/g
Calculation
(g fetus)(.14/g)(hct increment)
Hct of RBC unit
(1100 g)(.14/g)(.25) = 55 mL
.70
2
Kleihauer-Betke testing of a postpartum
specimen shows 6 fetal cells in a total of
2000 cells counted. How many vials of
RhIG should be given?
BV of a woman is
estimated 5000 mL.
1 vial RhIG is good
for 30 mL fetal
bleed
3
Kleihauer-Betke testing of a postpartum
specimen shows 2% fetal bleed. How
many vials of RhIG should be given?
1 vial RhIG is good
for 30 mL fetal
bleed
Ratio fetal cells = 6/2000 = .003 (or .3%)
Vol fetal bleed = (.003)(5000 mL) = 15 mL
RhIG = 15 mL/30 mL per vial
= 0.5 vial = rounded to 1 vial
Add one RhIG* = 2 vials
*AABB recommends adding I vial
2% = 0.02
Vol fetal bleed = (0.02)(5000) = 100 mL
RhIG = (100mL)/(30mL/vial) = 3.3 = 3 vials
AABB recommends adding I vial
3 vials + 1 vials = 4 vials to be given
4
A unit of red cells with a 50% hct is
(V1)(C1) =(V2)(C2)
(250)(.6) = (X)(.5)
ordered for an exchange transfusion.
X = 300
You have a 250-mL RBCs with a 60%
Final volume =300; starting volume = 250.
hct. How much plasma must be added
300-250 = 50 mL of plasma should be
to obtain an hct of 50%?
added.
5
A two-volume exchange transfusion is
Term BV=85 mL/kg Infant BV = (2.7 kg)(85 mL/kg) = 230 mL
ordered for a 2.7-kg full-term infant. The (V1)(C1) =(V2)(C2)
Total BV for exchange = 2(230) = 460 mL
requested hct is 50% (to be
Will need 2 units of RBCs.
reconstituted with FFP). The two RBCs
RBC#1 = (250 mL)(65%) = (X)(50%)
available are 250 mL and 260 mL, and
X = 325 mL final volume
both have a hct of 65%. How should the
Add (325-250) = 75 mL FFP to RBC#1
blood be prepared?
RBC#2 = (260 mL)(.65) = (X)(.5)
X = 338 mL
Add (338-260) = 78 mL FFP to RBC#2
*Note: 75 mL/kg is the approximate blood volume used for these examples
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 8 of 12
Sample Calculations
Yield and QC in Component Preparation; Relative Centrifugal Force
1a
1b
1c
2
3
4
Problem
A donor with a 225,000/uL platelet
count donates 500 mL Whole Blood
(WB). What is the total #platelets in the
WB?
6
(225,000/uL)(1,000uL/mL)(500mL)=1.13x10
3
(1,300,000/uL)(10 uL/mL)(61 mL)= 7.9x10
A 510-mL Whole Blood contains
225,000/uL platelets. A platelet
concentrate is made and has a total of
10
8.5 x 10 platelets. What is the platelet
yield?
CRYO is to be made from a 250-mL
FFP unit containing 0.6 IU/mL Factor
VIII. The CRYO made is 20 mL with
6.75 IU/mL Factor VIII. What is the
Factor VIII yield?
Your blood center performs CRYO QC
by pooling 4 bags of cryoprecipitate
and then assay for Factor VIII and
fibrinogen levels. The pool weighs 110
g. Test results of the pool show 304%
Factor VIII and 3577 mg/dL fibrinogen.
WB = (510 mL)(225x103/uL)(10 uL/mL)
11
= 1.15 x 10 platelets
10
Platelets =8.5 x 10 platelets
Yield = 0.85/1.15 = 73%
What is the RCF of a centrifuge with a
radius of 10 inches and a RPM of
4200?
What is the rpm to be set if the SOP for
making blood components states to do
a heavy spin at 5000 g for 6 minutes?
(The radius of your centrifuge is 10
inches.)
11
Note: this is the average number of
platelets in a typical Whole Blood
Same donor as 1a.
The platelet concentrate made from
this donor’s WB has 61 mL with a
count of 1,300,000/uL. What is the total
count in the unit?
Same donor as 1a.
What is the yield in the platelet
concentrate compared to the original
Whole Blood?
 The pool is 110 g. What is the
volume in mL?
 What is the average Factor VIII per
bag? Is QC acceptable?
 What is the average fibrinogen per
bag? Is QC acceptable?
5
Formula
10
Note: this is the average number of
platelets in a typical Platelet unit
10
7.9x10 = 70%
11
1.13x10
Note: the average yield in platelet
concentrate is 69%
3
FVIII in CRYO= (20 mL)(6.75 IU /mL) =135 IU
FVIII in FFP = (250 mL)(0.6 IU /mL) =150 IU
Yield = 135/150 = 90%
AABB requires:
FVIII ≥ 80 IU
Fibrinogen ≥150 mg
Specific gravity of
CRYO is 1.03
1% = 1 IU/mL
RCF=11.17 (r)(rpm/1000)2
r = radius in cm
RCF
= (28.38)( r)(rpm/1000)2
r = radius in inches
Factor VIII = (Factor VIII activity)(volume)
Fibrinogen = (fibrinogen activity)(volume)


Volume = 110 g /1.03 = 107 mL
Factor VIII
= (Factor VIII activity)(volume)
= 304%/100 = 3.04 IU/mL
= (3.04 IU/mL)(107 mL) = 325 IU
= 325/4 bags = 81 IU/bag (acceptable)
 Fibrinogen
= (Fibrinogen activity)(volume)
= (3577 mg/dL)/(100 mL/dL)(107 mL)
= 3827/4 = 957 mg/bag (acceptable)
2
RCF=11.17 (r)(rpm/1000)
r = cm
2
RCF = (11.17)(25.4)(4200/1000) = 5005
2
RCF = (28.38)( r)(rpm/1000)
r = inches
2
5000 = (28.38)(10)(X/1000)
2
5000/283.8 = (X/1000)
2
2
17.62 = X /1000
2
(17.62)(106) = X
6
X = Square root (17.62x10 ) = 4198 rpm
Lab Math
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Page 9 of 12
Sample Calculations
Antigen screening (Antigen prevalence of European ancestry used in these problems)
Problem
A patient has anti-E in the plasma.
What % Caucasian donors would be
compatible?
Formula
E = 30% positive
(approximate)
Calculation
E+ 30%
E- 70%; 70% would be compatible
2
A patient has anti-E. How many donor
RBCs should be screened to find two Enegative units for transfusion?
E+ 30%
E- 70%
3
A patient has anti-E and anti-K. How
many donor RBCs should be screened
to find 2 antigen-negative units?
E+ 30%; E- 70%
K+ 9%; K- 91%
70/100 donors should be compatible
However, you only need 2 units.
70/100 = 2/X;
X = 3 donor units to be screened
Need E-, K- donors. Multiply the % neg.
(.7)(.91) = .64 = 64% compatible
64/100 = 2/X
X = 3 donor units to be screened
4
A patient has anti-K and anti-Fy . What
% Caucasian donors would be
compatible?
5
A patient has anti-K and -Fy . How
many donor units should be screened to
find 4 compatible units?
6
A patient has anti-e, -K, -Jk . How
many donor units should be screened to
find 2 compatible units?
1
a
a
a
K- 91%
Fy(a-) 34%
K- Fy(a-) = (.91)(.34) = .31
31% Caucasian donors are compatible
K- 91%
Fy(a-) 34%
K-Fy(a-) = (.91)(.34) = .31
31% Caucasian donors are compatible
31/100 = 4/X
X = 13 donor units
e-, K-, Jk(a-) = (.02)(.91)(.24) = .0044
0.44% donors are compatible
0.44/100 = 2/X
X = 454 donor units
e- 2%
K- 91%
Jk(a-) 24%
HPC, MLC Relative Response, Relative Response
1
2
3
Problem
For HPC-M
A bone marrow donor weighs 80 kg.
What is the maximum volume of bone
marrow that can be collected?
Formula*
Max bone marrow
collection = 20
mL/kg
HPC
A recipient is 70 kg. What is the ideal
nucleated cells to be infused?
A donor is 70 kg. What is the normal
number of CD34 cells in the circulation?
Ideal = 3x10
cells/kg
8
Calculation
(80 kg)(20 mL/kg) = 1600 mL
8
10
(70 kg)(3x10 cells/kg) = 2.1 x 10
nucleated cells
6
CD+ cells = 1x10 /L
(70 kg)(75 mL/kg) = 5250 mL = 5.25 L
6
6
(5.25 L)(1x10 /L) = 5.25 x 10 cells
*Note: 75 mL/kg is the approximate blood volume used for these examples
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Lab Math
Page 10 of 12
Sample Calculations
Hardy-Weinberg equilibrium
Definition: Gene frequencies tend to remain constant from generation to generation: p + q = 1
This equilibrium can be expressed in algebraic term by the binomial expansion.
2
(p+q) =1
2
2
p + 2pq + q =1
1
2
Problem
2050 people were tested with anti-D,
and 1742 tested positive. What % of
people is D-positive?
Formula
Simple ratio
3162 people were tested with anti-X and
2403 tested positive. Assume X and x
are the two allelic genes:
Let p = X and q =x
2
(p+q) =1
2
2
p + 2pq + q =1
Calculate the following:
1. % of X-positive
2. Gene frequencies of X and x
3. % homozygous for the gene X
4. % heterozygous
% D+ 1742/2050 = 85%
% D- 15%
2403/3162 = .76
p+ = 76%
p- = 24%
2
2
2
2
p + 2pq + q =1
2
2
p + 2pq are p+ ; p- are the q
2
q = .24
q = .49
p + q =1
p = 1-.49 = .51
p + 2pq + q =1
2
2
(.51) + 2(.51)(.49) + (.49) = 1
.26 + .50
+ .24 = 1
26% are homozygous for p = X
50% are heterozygous for pq = Xx
24% are homozygous for q = x
IgG Half-life
1
2
Problem
A technologist received prophylactic
gamma globulin following a needle stick
on January 1. When will the injected
IgG drop to ¼ of the original level?
A woman received a 300-ug dose of
RhIG at 28 weeks of gestation. What is
th
the level of RhIG at delivery (40
week)?
Formula
Assume the half life
of IgG = 23-25 days
IgG ½ life = 23 days:
Jan 1 = 100%
Jan 23 = 50%
Feb 16 = 25%
IgG ½ life = 23 days:
Let’s approximate 23 days = 3 weeks
28 weeks = 300 ug dose injection
31 weeks = 150 ug
34 weeks = 75 ug
37 weeks = 37.5 ug
40 weeks = 19 ug
Lab Math
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Page 11 of 12
Sample Calculations
Budgeting and FTEs
1
Calculate the number of FTEs required
for the workload.
PTO/year:
Holidays/year:
Continuing education:
Productivity:
Annual test workload:
3 weeks
6 days
4 days
75%
800,000 units*
*in min/yr
2
Total days off/year = 3 weeks + (6+4 days) = 5 weeks
Total weeks worked/year = 52 - 5 = 47 weeks
Annual workload hours = Hours worked/year
= (47 weeks/year)(40 hrs/wk) = 1880 hrs/year
Productivity = (75%)(60 min/hr) = 45 min/hr
FTEs = ____Annual test workload______
(Annual workload hrs)(productivity)
FTEs = 800,000 min/yr
(1880 hrs/yr)(45 min/hr)
Which of the following methods
(Current Method A or Proposed Method
B) is more cost effective?
Test volume/month:
Productivity:
Worked hours/year:
Average salary:
Benefits:
900
75%
1840
$40,000
20%
Workload (unit/test):
Test cost (each):
A
25
$1.25
B
20
$1.50
= 800,000 min/yr = 9.45
84,600 min/yr
# Tests/year = (900 tests/month)(12 months) = 10,800
Productivity = (1840)(.75)(60 min/hr) = 828,00 min/yr
Workload:
Method A = (10,800 tests/year)(25 units/test) = 270,000 units/year
Method B = (10,800 tests/year)(20 units/test) = 216,000 units/year
Method A FTE = 270,000 units/yr = 3.26
82,800 min/yr
Method B FTE = 216,000 units/yr = 2.61
82,800 min/yr
Difference between Methods A and B = 3.26-2.61 = 0.65
(Method B saves 0.65 FTE/yr)
Salary = $40,000 + .20(40,000) = $48,000
Savings in salary = (48,0000)(0.65) = $31,200
Method A Cost of tests = ($1.25)(10,800)= $13,500
Method B Cost of tests = ($1.50)(10,800) = $16,200
Difference between Method A & B = $2700
Method B saving: Saving in salary-Add'l cost = $31,200 - 2700 =
$28,500
3
Your lab is evaluating which is a better
option: vaccinate all employees with
Hepatitis B without testing or first test
which employees already immunized
(has anti-HBs). There are 40 techs in
the lab and the hepatitis immunization
consists of a series of 3 injections at
$25 each injection. The second
method is to test which employee
already has anti-HBs at $20/test.
Which is more cost effective?
Cost of vaccination
(40 techs)(3 injections)($25 each) = $3000
Cost of testing and then vaccinate
(40 techs)($20/test) = $800
2 techs tested positive (do not need shots) = 38 do need shots
(38)(3)(25) = $2850+ $800 (cost of testing) = $3650
More cost effective to vaccinate entire staff.
Lab Math
Clare Wong, Rev 2016
©Gulf Coast Regional Blood Center
Page 12 of 12
Sample Calculations
Relative Risk and Disease Association
Of the 300 individuals with a certain disease, 250 share a common HLA antigen. The control group (no disease)
has 200 people and 10 have the HLA antigen. What is the Relative Risk (RR) that the HLA antigen is associated
with the disease?
What do we know?
200 normal people, 10 have HLA antigen
300 have disease, 250 have the HLA antigen
500 total people
This is our initial data. Set up a table
Disease+ DiseaseHLA+
250
10
HLA300
200
500
Now fill in the blank
Disease+
HLA+
250
a
HLA50
c
300
Disease10
b
190
d
200
260
240
500
RR* = ad = (patients with HLA) (control without HLA) = (250)(190) = 47500 = 95
bc
(control with HLA) (patients without HLA) (10)(50)
500
*Note: RR calculation in HLA reflects the frequency that a particular allele occurs with a disease relative to
its occurrence in normal healthy individuals. The calculations of RR for HLA is usually done by Woolf’s
method using the odds ratio (OR) = ad/bc. In contrast, RR in epidemiologic studies is: a(a+b)/c(c+d).
Sensitivity and Specificity
A new test is developed to diagnose an infectious disease. A total of 1000 patients with the disease were tested and
995 were found to be positive by the new test. The control group consists of another 1000 people who denied risk
factors for the infection, and 998 tested negative and 2 tested positive. What is the sensitivity and specificity of this
new test?
Disease+
Disease -
New test +
995 (TP)
2 (FP)
New test -
5 (FN)
998 (TN)
1000
(TP+FN)
1000
(FP+TN)
Sensitivity = TP/(TP+FN) = 995/(995+5) = .995 or 99.5%
Specificity= TN/(FP+TN) = 998/(2+998) = .998 or 99.8%