PMLS 2 P1
Lecture | Pre-analysis in Clinical Laboratory C.A.L.G
COVERAGE PRE-ANALYSIS
1. Pre-collection Variables All the complex steps MUST take place
2. Specimen Consideration BEFORE a sample can be analyzed.
3. Specimen collection (Overview &
Techniques 32-75% of testing error happens here
4. Pre-centrifugation & Centrifugation
Phases Careful attention is necessary in this
phase to ensure meaningful results
TESTING PHASE
Errors=extra work; diagnosis delayed;
PRE-ANALYTIC PHASE extra cost
Clinical need
PRE-ANALYTICAL
Order POTENTIAL ERRORS
FACTORS
Collect
Transport
Receive Improperly ordered
Sort Patient-related variables
tests, sample
(diet, age, sex, etc.)
Prepare/Centrifuge misidentification
Uncap (if needed)
Aliquot
Improper timing,
Patient preparation
ANALYTIC PHASE Improper fasting
Load sample on analyzer
Add sample/reagents Improper anticoagulant:
Mix Collection & Labeling
blood ratio
Incubate
Detect
Reduce data Preservatives &
Produce result Improper mixing
Anticoagulants
Review result
Repeat test (if necessary)
Release result Transport Incorrect order of draw
POST- ANALYTIC PHASE
Recap tube Hemolyzed/lipemic
Processing & Storage
Postprocessing storage specimens.
Report result
Access result
Interpret result
Integrate with other clinical info
Clinical action
, PMLS 2 P1
Lecture | Pre-analysis in Clinical Laboratory C.A.L.G
PRE-ANALYTICAL ERRORS
BEFORE COLLECTION
1. Incorrect test ordered
2. Inadequate patient preparation (e.g.,
not fasting, recent heavy meal-lipemia)
or improper timing (e.g., trough drug
level drawn too early)
3. Misidentification of patient
DURING COLLECTION
PATIENT-RELATED VARIABLES
1. Wrong container/wrong additive
2. Short draws/wrong anticoagulant/blood COLLECTION
ratio IN VIVO
(activity that can affect results)
3. Hemoconcentration from prolonged
tourniquet time
4. Hemolysis due to incorrect technique Tobacco smoking
(e.g., forcing blood through needle, Alcohol & drug ingestion
draw via intravenous line) IN VITRO
(within the glass; outside of living organism)
AFTER COLLECTION Hemolyzed
Icteric
1. Inadequate mixing/clots Lipemic
2. Mislabeling of specimen Hemodiluted/Concentrated
Anticoagulant use
3. Improper transport to lab: Exposure to
light/extreme temperatures or delayed TEST ORDER
delivery
4. Processing errors: Incomplete Laboratory tests are usually ordered
centrifugation, incorrect log-in. electronically or in writing.
improper storage or aliquoting prior to
analysis. Online computer input is the most error-
free.
PATIENT-RELATED VARIABLES
PHYSIOLOGY Verbal request are made only in
Diurnal Variation emergency situations and should be
Exercise documented on a standard form.
Fasting
Diet
Age/Gender/Race
Posture
Lecture | Pre-analysis in Clinical Laboratory C.A.L.G
COVERAGE PRE-ANALYSIS
1. Pre-collection Variables All the complex steps MUST take place
2. Specimen Consideration BEFORE a sample can be analyzed.
3. Specimen collection (Overview &
Techniques 32-75% of testing error happens here
4. Pre-centrifugation & Centrifugation
Phases Careful attention is necessary in this
phase to ensure meaningful results
TESTING PHASE
Errors=extra work; diagnosis delayed;
PRE-ANALYTIC PHASE extra cost
Clinical need
PRE-ANALYTICAL
Order POTENTIAL ERRORS
FACTORS
Collect
Transport
Receive Improperly ordered
Sort Patient-related variables
tests, sample
(diet, age, sex, etc.)
Prepare/Centrifuge misidentification
Uncap (if needed)
Aliquot
Improper timing,
Patient preparation
ANALYTIC PHASE Improper fasting
Load sample on analyzer
Add sample/reagents Improper anticoagulant:
Mix Collection & Labeling
blood ratio
Incubate
Detect
Reduce data Preservatives &
Produce result Improper mixing
Anticoagulants
Review result
Repeat test (if necessary)
Release result Transport Incorrect order of draw
POST- ANALYTIC PHASE
Recap tube Hemolyzed/lipemic
Processing & Storage
Postprocessing storage specimens.
Report result
Access result
Interpret result
Integrate with other clinical info
Clinical action
, PMLS 2 P1
Lecture | Pre-analysis in Clinical Laboratory C.A.L.G
PRE-ANALYTICAL ERRORS
BEFORE COLLECTION
1. Incorrect test ordered
2. Inadequate patient preparation (e.g.,
not fasting, recent heavy meal-lipemia)
or improper timing (e.g., trough drug
level drawn too early)
3. Misidentification of patient
DURING COLLECTION
PATIENT-RELATED VARIABLES
1. Wrong container/wrong additive
2. Short draws/wrong anticoagulant/blood COLLECTION
ratio IN VIVO
(activity that can affect results)
3. Hemoconcentration from prolonged
tourniquet time
4. Hemolysis due to incorrect technique Tobacco smoking
(e.g., forcing blood through needle, Alcohol & drug ingestion
draw via intravenous line) IN VITRO
(within the glass; outside of living organism)
AFTER COLLECTION Hemolyzed
Icteric
1. Inadequate mixing/clots Lipemic
2. Mislabeling of specimen Hemodiluted/Concentrated
Anticoagulant use
3. Improper transport to lab: Exposure to
light/extreme temperatures or delayed TEST ORDER
delivery
4. Processing errors: Incomplete Laboratory tests are usually ordered
centrifugation, incorrect log-in. electronically or in writing.
improper storage or aliquoting prior to
analysis. Online computer input is the most error-
free.
PATIENT-RELATED VARIABLES
PHYSIOLOGY Verbal request are made only in
Diurnal Variation emergency situations and should be
Exercise documented on a standard form.
Fasting
Diet
Age/Gender/Race
Posture
