Lab Errors

7/21/2019 Lab Errors

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Faculty of Medical Technology

Clinical Biochemistry

Laboratory errors

Collected and prepared by:

ESAM ALFAGE!

"th year of medical technology

#$%&'#$%"



Laboratory errors

What are lab errors?

Can we stop them?

How do we stop them?



Errors

REPORTING

INTERPRETING

ORDERING



Lab ErrorsLaboratory errors may be defined as ‘any

defect from ordering tests to reporting

results and interpreting ’Repeat sample?

Costs Money & ime



Phases of Lab Analysis:

!re analytical phase "#$

%nalytical phase '$

!ost analytical phase (#$

80% of errors are unrelated to analysis



Pre-analytical phase

oest )rdering*

o

+ample collection*o+ample transport to the lab*

o

+ample processing or preparation fortesting*



Test Ordering

,nsuitable tests*

!atient !reparation*

Handwriting* !atient misidentification*

)rders est on incorrect !atient*

Written )rders are not Correctly

ranscribed -L./ R.0*

Written )rders are not Legible*



.asting

!ostprandial

1efore or %fter Medication 2osage

%t specific time in a hormonal cycle

(Patient not obey the instructions

Patient Preparation



- Phleboto!y errors

- "ite selection 3 Choice of Collection %rea4

- Hematoma*

3 5ndwelling 56*

- Tube selection

"a!ple collection



3 Phleboto!y errors

3 Tourni#uet Application

-7o 8 ( Minute0*

3 Allo$ for %o!plete Dryin& of Alcohol*

3 "election of %orrect Nee'le "ie

-(9 to : ;auge May 1e ,sed0*

3 %o!plete )ill of Tubes

-)<er or under filling0*

"a!ple collection



Coagulation Tube Filling:



*an'lin& of Tubes Post %ollection

5n<ert as per Manufacturer’s 5nstructions

: 3(' times -%dditi<e 2ri<en0*

=ffects of 5mproper 5n<ersion -Clotted +amples0*

2o 7) +H%>= -*e!olysis0*



*an'lin& of Tubes Post %ollection

%<oid =cessi<e Heat or Cold -Hemolysis0*

7e<er =pose Whole 1lood to 2ry 5ce-Hemolysis0*

!rotect from Light if 7ecessary %mberubes*



"a!ple transport to the lab

3 ransport %ll +amples to the Laboratory as=fficiently as !ossible

3 Light eposure + #'$ drop of bilirubin

3 =cessi<e heat Hemolysis

3 ,nspun samples , >/ L2H/ %L/ %+/ %mmonia*+ ;lucose/ Ca@@*



"a!ple processin& or preparation fortestin&

3 2eli<ery to 2epartments

3 emporary +pecimen +torage

3 +pecimen +eparation

3 Centrifuging



Other pre-analytical

Variables

Controllable <ariables

7on controllable <ariables



%ontrollable ariables

3 2iet

3 Life style -smoAing/ alcohol ingestion/ drug

administration0

3 2rugs

3 !hysiological <ariables -prolonged bed rest/

eercise0



7on controllable <ariables

3 1iological <ariables - %ge/ se & race0

3 =n<ironmental <ariables -seasonal

influences0

3 )besity

3 !regnancy

3 +tress



Analytical errors: -testing0

3=Buipment4

%utomation <ersus manual 5nadeBuate D%

3Reagents4

uality/ +torage conditions/ =piry

3echniBue4

+pecificity & +ensiti<ity

3!ersonal -technologist0

ech fail to follow procedure*



Post-analytical:

3 Reporting*

3 yping errors*



Pre-analytical IssuesAssociated with Specien

Processing

Hemolysis

%llow complete clot formation to occur

Centrifuge promptly

3 speed -high speed lead to hemolysis0



*e!olysis

he presence of hemolysis

in the serum or plasma ofa sample appears as

a pinA or red color to the

liBuid*+ee the sample to the right*



%auses of *e!olysis

!rolonged tourniBuet application

5ncomplete alcohol drying following site

preparation*Rupture of red cells when collected with

small bore needle

issue trauma during collection*



%auses of *e!olysis

6igorous shaAing of collection tubes*

.reeEing of red blood cells during storage

or transportation*

=posure of cells to ecessi<e heat during

storage or transportation*



Hemolysis

, >/ C>/ L2H/ Mg*

+ ;lucose/ 1ilirubin*



.ost fre#uent causes of

pre-analytical errors)pen tube -container0*

ube not signed*

ube not correctly identified*

Clotted sample*

Wrong tube*

uantity 7ot +ufficient -7+0*

1roAen tube*HemolyEed sample*

LacA of signature*



Suggested !ualityindicators "or pre-

analytical phase

+tandard operating procedures -+)!0for specimen acceptanceDreFection*

5dentification of reasons for specimenreFection*



.iss-concept

Lab sta( alone are responsible for

lab errors)*+,-G ...

Labs/ 0hysicians and 0atients areAll +ES0,-SBLE)



Controlling Laboratory errors

' Continuous education)

' Automation)

' 1uality control21C3)

' nternal 1C: ' daily monitoring of precision 4 accuracy of a

particular lab 2calibrators 4 controls3)

' E5ternal 1C:

' long term accuracy of di(erent labs)



Than6s for your Attention)

We can only be as good as thesamples we receive!

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Lab Errors