STAT Tests

• Selected tests are available on a STAT basis 24 hours a day , 365 days a year.
• Normal business hours are Monday through Friday, 7:30 AM - 6:00 PM MST..
• For therapeutic reasons, some tests are drawn on a stat basis but not tested on a stat basis; such tests are designated as STAT-NRS in the test listing.
• An additional fee is charged for all services performed on a STAT basis or outside normal operating hours.

Confirmatory Testing

Because a number of pre-analytical and analytical factors can influence test results, HEMEX will repeat an assay at no charge if, in the physician's opinion, the test result does not correlate with the patient's condition. All requests for a repeat determination must be a on a new request form; the new specimen, the prior laboratory number, and the reason for the repeat determination must be specified on the new form.

Test Cancellations

Tests may be cancelled without charge prior to testing.  The client will be billed for any assays that have been started or completed prior to the request for cancellation. Flow Cytometry and Special Hematology samples often require a viablity test be performed prior to running the requested test. In this case, should the sample be unfit for testing or cancelled, the client will be charged for only the viability test.

Test Additions

Additional testing can be performed if sufficient specimen volume and integrity remain after the initial tests are completed.  All specimens are retained for a minimum of three months, if specimen integrity can be maintained. Requests to add on tests must be made by the ordering physician and will be documented on the original requisition. For add-on tests to inpatients, all requests should be routed through the hospital laboratory.

Interfering Substances

HEMEX maintains a complete list of chemicals, drugs, and other conditions which may interfere with assays.  This information is available upon request.
 

Selection of Methodology

When HEMEX has the capability of performing a test by more than one methodology and the client does not specify a method, HEMEX will select the method which has proven to provide the most clinically relevant data (i.e., an activity based assay will be performed instead of an antigenic assay).

Labels

All specimens received by the laboratory must be properly labeled.  The label must contain at the minimum:

• Last and first name of patient
•  ID Number
•  Date and time collected
•  Identification as Plasma or Serum

Requisitions

All specimens must be accompanied by a requisition. Preprinted requisitions are available from our Client Services Department. In order to avoid delays, all shaded areas should be completed legibly including patient name, ID, doctor name, birth date, sex, diagnosis, and pertinent clinical information.

Special Collection Considerations for Coagulation Testing

Difficult Draws

Difficulty with venipuncture may result in acceleration of clot formation produced by tissue products or hemolysis.  Such pre-activation of the clotting system may mask factor deficiencies, cause platelet clumping or give false positive and/or false negative results.  It is imperative that a poorly collected specimen be discarded rather than submitted for performance of tests of questionable significance.  In general, the greater the amount of blood needed, the larger the needle bore to ensure rapid laminar flow.  For most adults a 19 gauge needle is preferred.  A 21 gauge butterfly may be used for pediatric draws or "hard-to-draw" adults. Specimens may be collected in either evacuated tube systems or by a two syringe technique.

Order of Draw

If other laboratory work is being collected, use the second or third tube drawn for the coagulation testing.

Line Draws

When drawing blood from an indwelling catheter, the first 20 ml should be discarded (or used for other testing) and if from a heparinized line, the first 30 ml should be avoided for coagulation testing.

Choice of Anticoagulant

3.2% sodium citrate is the preferred anticoagulant for greatest sample stability. 3.8% sodium citrate may also be used. Always fill the vacuum tube to the maximum amount it will draw.

Patient Hematocrit

For hematocrits below 20% or above 60%, the ratio of sodium citrate to blood must be adjusted.  Please call 1-800-999-2568 or 602-997-9161 for instructions.

Transfer Containers

Containers should be of non-reactive materials to avoid activation of or interaction with the coagulation system.  Blue top tubes must be siliconized.  Specimens should be transferred with plastic pipettes and transported in  plastic tubes only.

Types of Specimens: Collection and Handling

Serum

Serum samples are obtained by drawing blood into a red top vacutainer tube containing no anticoagulant (corvac or other serum separator tubes may not be used unless specifically indicated by specimen requirements). All red top tubes should be allowed to clot at room temperature for 20 - 30 minutes, unless otherwise instructed.  Centrifuge and transfer the serum immediately to a plastic vial using a plastic pipette.  Do not refrigerate or freeze unspun specimens on the clot as this may alter test results.  Refrigerate or freeze the serum according to the test requirements. Please label the tube as "serum".

Whole Blood

Some test methodologies specify whole blood.  Draw the blood into the tube containing the specified anticoagulant:

 Sodium Citrate:  Light blue top
 EDTA:   Purple top
 Heparin:  Green top
 ACD-A:  Yellow top

Always fill the vacuum tube to the maximum amount it will draw.  Gently invert the tube 8 to 10 times to ensure proper mixing of blood and anticoagulant.  If you centrifuge the specimen and transfer the plasma to a transport tube, please label the tube as "plasma".  Please note under individual test listings that some whole blood specimens must be stored and transported at room temperature.

Plasma

Plasma samples are obtained by drawing blood into a tube containing an anticoagulant such as EDTA, heparin, or sodium citrate. Allow the tube to draw to the maximum amount it will draw  (Coagulation assays are standardized to a ratio of blood to sodium citrate of 9:1). Immediately after the blood fills the tube, invert it gently 8 to 10 times to ensure proper mixing. Centrifuge the specimen within 30 minutes of collection at a minimum of 2000 x g for 10 minutes for production of platelet free plasma. Plasma specimens submitted must be platelet poor ( platelet count <10,000).  It may be necessary to double spin the specimen to achieve this.

Remove the platelet poor plasma with a plastic pipette and transfer to a clean, plastic tube with a cap.  Aliquot 1 ml of plasma for each test ordered.  Please label each tube as "plasma". If not tested within thirty minutes of collection, the aliquot must be frozen.

Frozen serum or plasma specimens

Serum or plasma specimens must be frozen if stated in the specimen requirements.  It is essential to freeze the serum or plasma as soon as it has been separated from the cells.  Always freeze specimens in plastic tubes.  Do not fill completely to avoid tube breakage caused by expansion during freezing. Please specify that you have a frozen sample when you call for a sample pick-up.  Do not send a frozen specimen unless it has been packed in dry ice. Dry Ice must be obtained in your local area.

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