hematology chemistry coagulation

8/3/2019 Hematology Chemistry Coagulation

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Hem at o logy, Chem is t ry ,

Coagulat ion

Helpful Hints


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Hemato logy

A good check to see if yourComplete Blood Counts on your

patient results are valid is the

RULE OF THREE


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Hemato logy

Rules of Three for normal Hematology

Rule #1

Hgb X 3 = Hct +/-2Rule #2

RBC x 3.3 = Hgb +/- 1.5

Rule #3RBC x 9 = Hct +/3


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Hemato logy

The laboratory must verifycalibration on the instrument

every 6 months or on an asneeded basis to ensureaccuracy of the system.


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Hemato logy

And why else would calibration benecessary?

1. Critical parts are replaced such asmanometers, apertures, or detectorcircuit boards

2. Controls show an unusual trend or

are outside of acceptable limits andcannot be corrected bymaintenance or troubleshooting.


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Hemato logy

Low platelet counts on an individualthat has no bleeding symptoms, trychecking the blood smear for platelet

clumping or platelets satellitingaround the neutrophils


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Hemato logy

To help correct this problem, usesodium citrate as an alternativeanticoagulant (because EDTA

induced platelet clumping) andmultiply the citrate platelet count andWBC by 1.11 to correct for

anticoagulant dilution


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Hemato logy

What should you be doing if youhave two different hematologyinstruments?

Or if you have two instruments thatare the same


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Hemato logy

Comparison check


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Hemato logy

Do not use non Clorox bleach or anyscented Clorox bleach for cleaningthe instruments.

If you can not get Clorox, then


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Chemis t ry

The laboratory must very calibrationevery six months or on an asneeded basis to ensure accuracy of

the system.


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Chemis t ry

And why else would calibration benecessary?

1.Critical parts are replaced2.Controls show an unusual trend or

are outside of acceptable limits andcannot be corrected by maintenanceor troubleshooting.


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Coagulat ion

If you are using a manual or semi-automated method for your APTTs,the timing of the incubation of your

patient plasma + reagent is critical.The Timing of your duplicate testingneeds to be precise. Any deviations

in timing will usually result in theduplicate test results not matching.


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The tests needs to be run with thesame timing limits as the controls.

So what does that mean you shouldbe checking?


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Coagulat ion

Your timer!


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Controls (normal and abnormal) aretypically valid for one year.

Ranges are not established so youmust establish your own ranges.

Run the controls a minimum of 30times to establish the mean andSDs.


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Qual i t y Cont ro l

Internal Quality Control

Reagent Check (Parallel Testing)

External Quality Control (proficiencyprograms)

Blind Samples

Competency Checks


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Quality control material

Quality control ranges

Plotting results (Levey-JenningsGraphs)

Reviewing Results

Corrective Action Logs

Reagent Checks (parallel testing)

Review & Signature


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Do you have appropriate controls foreach procedure?

Quantitative: low (normal) & high

normal & abnormal


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Do you treat your control materiallike the patient samples?

Are the control results verifiedBEFOREpatient results arereleased?


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How often do you run your controls?

*per manufacturers instructions*per laboratory guidelines

*can always run more than

recommendation*balance time, cost and efficacy


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General Guidelines

CBC: per 8 hour shift

Manual Differentials/BPS: per day(stain check)

Chemistry: per 8 hour shift


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Document results on run sheet or QC log

Include lot #s & expiration dates

Include tech initials & run date

For QT assays,

Manufacturers Mean & Range (~+2.5SD)

Internal Mean + 2 & 3 SDLevey-Jennings Control Charts


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Why use Levey-Jennings controlcharts?

Patterns

1:2s, 1:3s

Dispersion (loss of precision)

Trend

Shift


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Lab supervisor review if exceeded

(*before patient results are

released) Corrective action if needed

(document)

Retest if required


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QC failures must be reviewed andsigned off by lab supervisor or higher

All unexpected or failed QC results must

be documented Corrective Action Log Final action must demonstrate problem

was resolved

Lab Sup/Mgr must review/sign CA Logs

at least monthly Must have CA log for every

test/equipment/system


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Why do parallel testing?

Consistency of patient resultsTransition of control


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Chemistry: New control lot inparallelmean/SD

CBC/FBC: New control lot inparallel 3-5 days


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At the October Meeting:

Westgard Rules

Normal Values

QC and corrective action

QA

Instrument Validation

Carryover Studies

hematology chemistry coagulation

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