Specimen Handling - General Requirements
PEDIATRIC PROGRAM AND SPECIMEN COLLECTION
Quest Diagnostics is committed to solving the special laboratory testing needs of pediatricians and other providers who care for infants and children younger than 18 years of age. Our leaders at Quest Diagnostics Nichols Institute include clinically-trained, board-certified pediatric specialists who clearly recognize the need to manage small sample volumes and provide age-specific reference ranges. Using the expertise of our on-site Medical Directors, Scientific Directors, and University-based Academic Associates, we have developed (and continue to expand) a Pediatric Program designed to be flexible, creative, and diligent in all areas of pediatric test development and performance.
Our Clinical Correlations Department has established reference ranges based on chronological age, with additional ranges for most sex steroids based on Tanner stage of pubertal development. New tests are developed regularly at Quest Diagnostics Nichols Institute, and we invite interested clinicians to participate in Institutional Review Board-approved studies designed to establish valid pediatric reference ranges for these new assays.
For each test, the specimen type, preferred and minimum specimen volume, preferred shipping/storage temperature, and any special handling notes are specified. The preferred volume is an amount sufficient to allow multiple runs of the assay either singly or in duplicate. The minimum volume allows one single analysis including instrument dead volume. In some situations, it may be possible to assay samples below the stated minimum volume (see below). Storage temperature is specified as room temperature (15-30° C), refrigerated (2-10° C) or frozen (-20° C or colder). When temperature is not indicated, the sample may be stored and shipped in the most convenient manner for the client.
Successfully Managing Minimum Volume Samples
A common problem in pediatric laboratory testing is the limited volume of available sample. Pediatric samples require different handling and individualized processing. To ensure that a pediatric sample receives special attention, please consider one or more of the following options:
- Flagging the tube and requisition: Red labels with the word “Pediatric”. Place a label on the tube as well as in a blank area of the Test Request Form (or on the link manifest).
- Using Pediatric Cards in Specimen Bags: Pediatric cards may be placed in Nichols Institute plastic specimen bags to allow up-front identification and special handling of the pediatric specimens within. These cards are available through Nichols Institute.
- Up-front notification: Notify Client Services if you have a sample that is close to or below the listed minimum volume. This will allow us to flag the sample in the system to receive special attention. If possible, please supply the name and contact information for the ordering physician/provider so that we may determine the priority of the various tests ordered. The ordering physician may also write down the priority of testing ahead of time on the Test Request Form.
Please note that, in some cases, we may be able to perform an assay on a sample whose volume is less than the stated minimum (typically by performing the test on a diluted sample, if the assay and the clinical situation permit). Please call Client Services to arrange for consultation.
Specimen Collection: Serum, Plasma, or Blood
Draw blood in the color-coded vacutainer tube indicated in the alphabetical test listing. For serum or plasma, draw approximately 2 1/2 times the requested volume. For serum, allow the blood to clot at least ten minutes and separate by centrifugation. For plasma and whole blood, completely fill the vacutainer whenever possible to eliminate dilution from the anticoagulant or preservative and immediately mix the blood by gently and thoroughly inverting the tube five to ten times. Separate plasma by centrifugation. Transfer the serum, plasma or whole blood to a plastic transport tube (see Pediatric Specimen Tubes below).
Specimen Collection: Urine
Most urine chemistry tests require a 24-hour collection. Record on the test request
form any medications that the patient is receiving. If a preservative is required,
it is important that the designated preservative be in the urine collection container
at the start of the collection. When the 24-hour urine output is less than 1 liter,
4 grams of boric acid can be used when boric acid is the specified preservative
or 10 mL of 6N HCl can be used when HCl is specified. The patient (or responsible
individual) should be cautioned that the preservative may be toxic and caustic,
and not to spill or discard the preservative.
On the day of the collection, discard the first morning urine void, and begin the collection after this void. Collect all urine for the next 24 hours so that the morning urine void on the second day is the final collection. Measure the total 24-hour urine volume. Record this volume on the test request form and on the urine transport vial (see Pediatric Specimen Tubes below). Transfer the requested volume into the labeled urine transport vial. Do not send the entire urine collection.
Pediatric Specimen Tubes
Pediatric color-coded Vacutainer tubes are provided to facilitate special handling.
Special small conical tubes with screw caps are provided to prevent evaporation
of small volume samples. These tubes will hold up to 1.5 mL of specimen. Standard
Quest Diagnostics specimen transfer tubes should be used for larger volume samples.
For urine specimens, use Quest Diagnostics urine vials. For those tests requiring
specimens be protected from light, amber vials for serum or urine may be obtained
by calling client supplies.
We generally request 1 tube per test to avoid delays in processing and to expedite turnaround time. To minimize specimen volume requirements for small children, however, only one tube is required even when multiple tests are ordered.
Each tube or container should be labeled as follows:
- Patient Name
- Patient Date of Birth*
- Client Name
- Client/Patient #
- Date of Collection
- Time of Collection
- Test Codes Ordered
For pediatric specimen tubes, wrap the label around the tube just below the screw cap so the ends of the label adhere to each other and the information stipulated above can be read. When using the standard tubes, affix the label lengthwise down the tube. Special yellow tube labels for pediatric samples will further identify each specimen.
It is important to indicate patient age so that appropriate reference ranges can be assigned for reporting purposes. The patient’s age may also assist the technologist in choosing the appropriate initial sample dilution for the assay.