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)