Unit 9 - Specimen Handling Flashcards
T/F
As part of the computerization network that connects many aspects of patient care, the laboratory network tracks patient specimens from the time they are collected until the results are reported.
T
The quality of results depends on proper handling of the specimen in the __________.
Preanalytical phase
Includes all the steps taken before the actual testing of the sample.
Preanalytical phase
It has been estimated that __% to __% of all laboratory errors occur prior to analysis.
46% to 68%
Specimen handling is a critical part of this phase.
Preanalytical phase
__________ handling from the time a specimen is collected until the test is performed helps ensure that results obtained on the specimen accurately reflect the status of the patient.
Proper
__________ handling is a preanalytical error that can render the most skillfully obtained specimen useless or affect the analyte (substance undergoing analysis) in a way that causes erroneous (invalid) or misleading test results, which in turn cause delayed or incorrect care for the patient.
Improper
Substance undergoing analysis.
Analyte
Factors that alter test results introduced into the specimen before TESTING, including before, and during COLLECTION, and during TRANSPORT, PROCESSING, and STORAGE.
Preanalytical errors
T/F
It is not always easy to tell when a specimen has been handled improperly.
T
T/F
To ensure delivery of a quality specimen for analysis, it is imperative that all phlebotomists be adequately instructed in this area so that established policies and procedures are followed.
T
Additive tubes require from __________ gentle inversions
3 to 10
T/F
The required number of inversions also depends on the type of additive.
T
Gentle inversion helps to distribute the additive evenly while minimizing the chance of __________.
Hemolysis
T/F
Vigorous mixing can cause hemolysis and should be avoided.
T
Examples of tests that cannot be performed on hemolyzed specimens.
Potassium (K+)
Magnesium (Mg2+)
Enzyme tests
Inadequate mixing of anticoagulant tubes leads to __________ formation, which can cause erroneous test results, especially for __________ studies.
Microclot; hematology
T/F
Inadequate mixing of gel separation tubes may prevent the additive from functioning properly, and clotting may be incomplete.
T
T/F
Nonadditive tubes do not require mixing.
T
T/F
It is important to handle and transport blood specimens carefully.
T
T/F
Rough handling and agitation can __________ specimens, activate __________, and affect __________ tests as well as break tubes.
Hemolyze; platelets; coagulation
Tubes should be transported stopper UP to reduce __________, aid clot formation in serum tubes, and prevent contact of the tube contents with the tube stopper.
Agitation
Blood in contact with tube stoppers can be a source of specimen contamination and can contribute to __________ formation during stopper removal.
Aerosol
These are typically placed in plastic bags for transportation to the laboratory.
Blood specimen tubes
Guidelines that require specimen transport bags to have a biohazard logo, a liquid-tight closure, and a slip pocket for paperwork.
CLSI and OSHA guidelines
These are transported in leak-proof containers with adequately secured lids.
Nonblood specimens
All specimens transported through pneumatic tube systems should be protected from _____ and _____ in zipper-type plastic bags to contain spills.
shock; sealed
T/F
All specimens should be transported to the laboratory without delay.
T
Routine blood specimens should arrive at the laboratory within __ minutes of collection.
45
Specimens that require separation of the serum or plasma from the cells should be centrifuged within __ hour of arrival in the lab.
1
CLSI guideline H18-A3 sets the maximum time limit for separating serum and plasma from the cells at __ hours from time of collection unless evidence indicates that a longer contact time will not affect the accuracy of the test result.
2
Less time is recommended for some tests, such as those for __________ and __________.
Cortisol; potassium
Prompt delivery and separation minimize the effects of metabolic processes, such as __________.
Glycolysis
It also affects other analytes, such as ALDOSTERONE, CALCITONIN, ENZYMES, and PHOSPHORUS.
Cellular metabolism
Glycolysis by erythrocytes and leukocytes in blood specimens can falsely lower glucose values at a rate of up to _____ mg/L per hour.
200 mg/L
T/F
Nonadditive and gel-barrier serum tubes, such as SSTs, must be completely clotted before centrifugation.
T
T/F
Heparin gel-barrier tubes, such as PSTs, can be centrifuged right away.
T
T/F
Specimens in gel barrier tubes do require manual separation after they have been centrifuged.
F
The separator gel lodges between the fluid and the cells during centrifugation, becoming a physical barrier that prevents __________ for up to 24 hours
Glycolysis
T/F
EDTA tubes and specimens for other tests performed on WHOLE BLOOD should never be centrifuged.
T
T/F
Applicable temperature requirements for all specimens should be maintained until they are turned over to the courier service.
T
Specimens that take priority over all other specimens and should be transported, processed, and tested immediately.
“STAT” or “medical emergency”
Blood smears made from EDTA specimens must be prepared within __ hour of collection to preserve the integrity of the blood cells and prevent _____ formation due to prolonged contact with the anticoagulant.
1; artifact
EDTA specimens for CBCs should be analyzed within __ hour/s, but are generally stable for __ hours at room temperature.
6; 24
CBC specimens collected in microcollection containers should be analyzed within __ hours.
4
EDTA specimens for erythrocyte sedimentation rate (ESR) determinations must be tested within __ hours if left at room temperature or within __ hours if refrigerated.
4; 12
EDTA specimens for reticulocyte counts are stable up to __ hours at room temperature and up to __ hours if refrigerated.
6; 72
Glucose test specimens drawn in sodium fluoride tubes are stable for __ hours at room temperature and up to __ hours when refrigerated at __°C to __°C.
24; 48; 2°C to 8°C
Prothrombin time (PT) results on unrefrigerated and uncentrifuged specimens are reliable for up to __ hours after collection.
24
Partial thromboplastin time (PTT) test specimens require analysis within __ hours of collection regardless of storage conditions.
4
Partial thromboplastin time (PTT) test specimens require analysis within __ hours of collection regardless of storage conditions.
4
T/F
When blood leaves the body it is exposed to the effects of temperature and light that can negatively affect analytes.
T
T/F
Specimens for those significantly affected require special handling to protect them.
T
Body temperature
36.4°C–37.6°C (37°C average)
Room temperature
15°C–30°C
Refrigerated temperature
2°C–10°C
Frozen temperature
-20°C
Some specimens require ___°C or lower.
-70°C
T/F
Some specimens will precipitate or agglutinate if allowed to cool below body temperature. These specimens need to be transported at or near the normal body temperature of 37C.
T
T/F
Most of these specimens require collection in a tube that has been prewarmed to 37°C.
T
T/F
Small, portable heat blocks that are kept in a 37°C incubator until needed are available for transporting body-temperature specimens.
T
The heat blocks hold this temperature for approximately __ minutes after removal from the incubator.
15
T/F
Temperature-sensitive specimens that can withstand temperatures slightly higher than 37°C can be wrapped in an activated heel warmer for transport.
T
T/F
Some metabolic processes that can affect test results continue in the specimen after collection.
T
Chilling the specimen __________ metabolic processes and protects analytes.
Slows down
T/F
Blood specimens that require chilling should be completely immersed in a slurry of crushed ice and water and either tested immediately or refrigerated upon arrival in the laboratory.
T
T/F
Large cubes or chunks of ice without water added do not allow adequate cooling of the entire specimen.
T
T/F
Contact with a solid piece of ice can freeze parts of the specimen, resulting in hemolysis and possible analyte breakdown.
T
T/F
Contact with a solid piece of ice can freeze parts of the specimen, resulting in hemolysis and possible analyte breakdown.
T
T/F
Some specimens are negatively affected by chilling.
T
T/F
Potassium levels artificially decrease if the specimen is chilled.
F
T/F
When a potassium test is ordered with other analytes that require chilling, it should be collected in a separate tube.
T
T/F
Some analytes are broken down by light, resulting in falsely decreased values.
T
Most common light-sensitive specimen.
Bilirubin
Bilirubin decrease by up to __ after 1 hour of light exposure.
50%
An easy way to protect a blood specimen from light is to wrap it in __________.
Aluminum foil
T/F
Light-blocking, amber-colored microcollection containers are also available for collection of infant bilirubin specimens.
T
T/F
Amber containers for urine specimen collection are also available.
T
T/F
Light-blocking secondary specimen transport containers are available as well.
T
This is where specimens are received and prepared for testing.
Central processing or triage
Here the specimens are identified, logged/accessioned, sorted by department and type of processing required, and evaluated for suitability for testing.
Central processing or triage
Specimens to keep at 37°C.
Cold agglutinin
Cryofibrinogen
Cryoglobulins
Chill in crushed ice slurry
Angiotensin-converting enzyme (ACE)
Ammonia
Catecholamines
Free fatty acids
Gastrin
Glucagon
Homocysteine
Lactic acid
Parathyroid hormone (PTH)
pH/blood gas (if indicated)
Pyruvate
Renin
Specimens to be protected from light.
Bilirubin
Carotene
Red cell folate
Serum folate
Vitamin B2, 6, 12, and C
Urine porphyrins
Urine porphobilinogen
__________ specimens are required for accurate laboratory results.
Suitable
__________ specimens must be rejected for testing and new specimens obtained.
Unsuitable
The most frequently cited reason for rejection of chemistry specimens is __________, followed by insufficient amount of specimen, or ___.
Hemolysis; QNS
The most frequent reason for rejection of hematology specimens.
Clotting
T/F
Inadequate, inaccurate, or missing specimen identification should be rejected.
T
T/F
Additive tubes containing an inadequate volume of blood should be rejected.
T
T/F
Hemolysis intended for potassium determination should be rejected.
T
T/F
Urine specimen that is not labeled should be rejected.
T
T/F
Partially filled coagulation tubes should be rejected.
T
T/F
A wrong tube like a CBC specimen collected in red top tube should be rejected.
T
T/F
Outdated tube should be rejected.
T
T/F
A lavender top tube with a CBC specimen that has clots in it due to improper mixing should be rejected.
T
T/F
Contaminated specimen like a urine specimen for culture and sensitivity in an unsterile container should be rejected.
T
T/F
QNS should be rejected.
T
T/F
Wrong collection time should be rejected.
T
T/F
Exposure to light should be rejected.
T
T/F
Delay in testing should be rejected.
T
T/F
Delay in errors or processing should be rejected.
T
A specimen for an erythrocyte sedimentation rate in an EDTA tube is stable only for __ hours at room temperature and __ hours if refrigerated.
4; 12
Sodium citrate specimens older than 4 hours will give incorrect ___ results.
PTT
T/F
Serum tubes that have not been spun within 2 hours or refrigeration of serum tubes before centrifugation will increase some analytes, such as potassium, creatinine, phosphorus, LDH, and decrease analytes, such as glucose, ionized calcium, and CO2. Therefore, it should be rejected.
T
A machine that spins blood and other specimens at a high number of revolutions per minute (rpm).
Centrifuge
T/F
The centrifugal force created causes the cells and plasma or serum in blood specimens to separate.
T
T/F
Specimens for tests that require serum or plasma samples must be centrifuged.
T
_____ should remain on tubes awaiting centrifugation.
Stoppers
T/F
Removing the stopper from a specimen can cause loss of CO2 and an increase of pH, leading to inaccurate results for tests such as pH, CO2, and acid phosphatase.
T
T/F
Leaving the stopper off exposes the specimen to evaporation and contamination.
T
T/F
Sources of contamination can be as simple as a drop of sweat, which interferes with electrolyte results, or powder from gloves, which may interfere with calcium determinations.
T
T/F
Evaporation leads to inaccurate results because of concentration of analytes.
T
T/F
Stoppers should also be left on tubes during centrifugation to prevent contamination, evaporation, aerosol (fine spray) formation, and pH changes.
T
T/F
Equal-size tubes with equal volumes of specimen must be placed opposite one another in the centrifuge.
T
Unbalanced centrifuge may break specimen tubes, ruining specimens and causing the contents to form __________.
Aerosols
T/F
The lid to the centrifuge should remain closed during operation and should not be opened until the rotor has come to a complete stop.
T
T/F
A specimen should never be centrifuged more than once.
T
Repeated centrifugation can cause _____ and _____ and alter test results.
hemolysis; analyte deterioration
T/F
Once the serum or plasma has been removed, the volume ratio of plasma to cells changes.
T
T/F
A centrifuge generates heat during operation, specimens requiring chilling should be processed in a temperature-controlled refrigerated centrifuge.
T
T/F
Specimens for tests performed on plasma that are collected in tubes containing anticoagulants may be centrifuged without delay.
T
__________ tests are typically collected in green top heparin tubes to save time, because plasma specimens can be centrifuged right away.
STAT chemistry
T/F
Serum specimens that must clot first before centrifugation.
T
If clotting is not complete when a specimen is centrifuged, __________ may clot the serum and interfere with the performance of the test.
Latent fibrin formation
Complete clotting normally takes __________ at room temperature.
30–60 mins
Specimens from patients on anticoagulant medication, such as _____ or _____, specimens from patients with high white blood cell counts, and chilled specimens may take longer to clot.
Heparin; warfarin
Serum separator tubes and other tubes containing clot activators usually clot within __ minutes provided they are mixed properly immediately after collection.
30
Thrombin tubes (RST), clots in __ minutes.
5
T/F
All tube stoppers should be pulled straight up and off and not “popped” off using a thumb roll technique.
T
T/F
All tube stoppers should be pulled straight up and off and not “popped” off using a thumb roll technique.
T
T/F
Pouring the serum or plasma into aliquot tubes is not recommended because it increases the possibility of aerosol formation or splashing.
T
T/F
Transfer of specimens into aliquot tubes has an inherent risk of error.
T
T/F
Great care must be taken to match each specimen with the corresponding aliquot tube to avoid misidentified samples.
T
T/F
Serum and plasma are virtually indistinguishable once they have been transferred into the aliquot tubes.
T
T/F
It is important to match the specimen with both the aliquot tube of the requested test and the patient.
T
T/F
Never put serum and plasma, or plasma from specimens with different anticoagulants, in the same aliquot tube.
T
