LC9 Flashcards
2 steps involved in processing and handling different types of specimens
- Specimen Handling
- Routine Handling
a critical phase in obtaining quality results
Specimen Handling
__ % to ___ % laboratory errors occur in the pre-analytical phase
46% to 68%
when does pre-analytical errors usually occur
- Before collection
- At time of collection
- During specimen transport
- During specimen processing
- During specimen storage
2 considerations in routine handling
- Mixing tubes by inversion
- Transporting specimens
General number of inversions for tubes
3-10 gentle inversions
Number of inversions for coagulation tests
3-4x
Number of inversions for tubes with clot activator and gel
5x
T/F Rough handling can lead to undesirable conditions which might hemolyze the specimens, activate platelets, affect coagulation, and break the glass tube.
True
3 reasons why specimens should be transported with a stopper
- To avoid contact between content and stopper
- To minimize agitation of the specimen
- To aid clot formation for serum tubes
Where are blood specimen tubes placed when they are transported?
Liquid-tight closure plastic bag with biohazard logo and slip pocket for paperwork
transported in leak-proof containers with adequately secured lids
Nonblood specimens
tube system used to transport nonblood specimens
Pneumatic tube systems
Routine blood specimens should arrive at the laboratory within __ minutes of collection
45
Time required for specimen to be separated from serum or plasma for centrifugation
1 hour
Time limit for separating serum and plasma from cells
2 hours from time of collection
Prioritized specimens are under what category
STAT or medical emergency specimens
Time Limit Exceptions
EDTA specimens
1 hour
Time Limit Exceptions
EDTA specimens for CBCs
6 hours; 24 hours at room temp
Time Limit Exceptions
EDTA specimens for ESR
4 hours
Time Limit Exceptions
EDTA specimens for reticulocyte counts
6 hrs; 12 hours if refrigerated
Time Limit Exceptions
Glucose Test
24 hrs at room temp; 48 hrs if refrigerated
Time Limit Exceptions
PT test results
24 hrs at room temp
Time Limit Exceptions
PTT results
4 hrs
3 considerations for special handling
- Body temperature specimens
- Chilled Specimen
- Light-Sensitive Specimen
Temperature for Body temperature specimens
36.4C - 37.6C; 37C average
T/F Specimens will precipitate or agglutinate if allowed to cool below body temperature
True
Examples of specimens that should be at room temperature
Cold agglutinin, cyrofibrinogen and cyroglobulins
T/F Chilling specimens can slow the metabolic process
True
Examples of tests that requires chilled specimens
ACTH, acetone, ammonia, lactic acid, PTH, renin
How are light-sensitive specimens transported
Tube is wrapped with aluminum foil or is on an amber-colored container
Examples of tests that requires light-sensitive specimens
Bilirubin, carotene, vitamin B12, Vitamin C
where chilled specimens are placed when they are being transported
slurry of crushed ice and water
processing areas where specimens are centrifuged and separated from the cells to protect analyte stability
Central Processing or Triage
Reasons for Rejection
- Specimen is not identified properly
- QNS
- Hemolysis
- Ratio of additive with blood
- Contaminated specimen
- Wrong tube
- Outdated tube
- Exposure to light
- Improper handling/mixing
- Did not follow testing limits
- Incorrect collection time
- Delay
machine that spins blood and other specimens at a high number of revolutions per minute
Centrifuge
causes the cell and plasma or serum in blood specimens to separate
Centrifugal force
T/F Stopper should remain on tubes while awaiting centrifugation
True
Reasons why stoppers should remain on tube when centrifuged
- Contamination
- Evaporation
- Interfering substances
- Aerosol formation
- pH changes
T/F Specimen can be centrifuged more than oncce
False
T/F It is not crucial that tubes should be balanced and are equal in size.
False
Difference of plasma and serum specimens when centrifuged
- Plasma specimens - collected in tubes with anticoagulants and should be centrifuged immediately and without delay
- Serum specimens - needs to be completely clotted first prior to centrifugation
happens when serum specimen is not clotted before centrifuge
fibrin formation may clot the serum and interfere the performance of the test
Complete clotting time
30-60 minutes
where are plasma specimens centrifuged
StatSpin Express 2 Centrifuge
portion of a specimen used for testing and is used for multiple testing
Aliquot Preparation
T/F Specimens with different anticoagulants should not be put in the same aliquot tube.
True
used when transferring serum or plasma into aliquot tubes
Disposable transfer pipettes
OSHA Act RA 11058 states that..
everyone who’ll handle potentially infectious materials should wear PPEs
Universal Precaution in the laboratory
treat all samples as potentially infectious
