Chapter 9: Outside Diagnostic Laboratory Services

The lab must offer services and tests that the veterinarian is looking for.
Some specialize in specific tests and have the newest technology available.
Standard laboratory services should include analysis for biochemical profiles, CBCs, cultures, cytology, and histopathology.
Labs should abide by guidelines set forth by the Clinical and Laboratory Standards Institute (CLSI) and adhere to the strict guidelines outlined by the US Food and Drug Administration (FDA).
All labs should continually monitor and perform quality controls for accuracy and reproducibility by internal and external quality assurance programs.

Correct sample submission is critical for the tests required.
Many tests require serum, not plasma.
Serum is produced when a red-topped tube (RRT) is centrifuged, separating the red blood cells and coagulation proteins from the liquid portion of the blood.
Red topped tubes should be allowed to clot for 15 to 20 minutes before centrifugation.
The sample can then be spun for 10 to 15 minutes at $2500$ rpm.
The serum can then be removed from the clot and placed in a plain glass red-topped tube for transport.
If a serum separator tube (SST) has been used, there is no need to remove the serum.
Do not use SSTs for therapeutic monitoring, such as for digoxin, phenobarbital, or theophylline levels.
Examples of tests requiring serum: chemistries, immunology, endocrinology, phenobarbital, digoxin, theophylline.

Plasma is produced when the blood sample is spun with a specific anticoagulant. The liquid portion of the sample without red blood cells is the plasma.
EDTA is an anticoagulant that is added to a lavender-topped tube (LTT), preventing clotting of the blood.
Other anticoagulants are lithium heparin, sodium heparin, and potassium citrate.

Tissue samples submitted to the lab for histopathology require fixation with formalin.
Formalin is a preservative that maintains the tissue characteristics for transport.
The specimen container should contain $10\%$ formalin at 10 times the volume of the tissue.
Formalin is a known carcinogen – it should not be inhaled and gloves and eye protection should be worn when handling it.

Cytology samples may need to be stained or unstained depending on the test and the facility.
Do not submit in the same bag as a formalin container as the fumes can degrade cytology samples.

Culture samples must indicate the source of the sample as well as specify whether it is anaerobic (without air) or aerobic (with air).
Aerobic cultures should be kept at room temperature and processed within 48 hours of sample collection.

Samples (blood tubes, biopsy jars, and slide containers) must be clearly marked with the patient’s name, date, and type of specimen (urine, serum, plasma, etc.).
All slides and/or caps must be secured to prevent the sample from leaking or formalin from spilling.
A protective, absorbent material should be wrapped around individual samples to prevent the sample from being broken during shipment.
Slides should be packaged in a slide container to prevent the glass from breaking.

Must be filled out correctly.
Vital information: species, age, gender, breed, patient name, client name, date, and the submitting doctor’s name.
Mark the specified test correctly.
Pathology samples: history of the pathology is very important.
Copies of submission forms should be kept for records so the team knows which laboratory was selected, where tests were submitted, and on which date.

Proper sample submission is absolutely critical when submitting samples.
Instructions must be followed for various tests to be completed.
Some samples need to be submitted with an ice pack to keep the sample cool during shipment, others need to be submitted frozen, and other have no specific holding requirements – Keeping the samples chilled preserves cell function.
Some shipments may need to be sent overnight whereas others may be sent by Priority Mail.

Some labs may provide a courier service for sample pickup.
Samples may be shipped by other courier services (e.g. UPS, FedEx, DHL) – Timing of pickup may determine which courier is used – It is ideal to have samples picked up late in the day.

Results should be received in a timely fashion.
Results should have a reference range listed than indicated the normal ranges for that test.
Results may be reported by fax, phone, or Internet.
Practices with electronic medical records may choose to have results automatically populated into the medical record with alerts set when the results are available.

For the practice to recover hidden costs associated with laboratory analysis, the practice must at least double the cost of the testing to the client.
Costs that must be considered include:
- The time it takes to obtain, draw, and prepare the samples
- The costs of supplies used to obtain the sample if the lab does not provide them (syringe, needle, formalin, slides)
- Some laboratories may add a fuel surcharge to the monthly statement
- Shipping fees if samples are submitted to labs other than those used for general analysis. This may include overnight fees to FedEx or UPS.
- Interpretation of results

Calls are answered in a timely manner.
Lab personnel should be friendly and provide the answers needed.
The lab should call the veterinarian back within one business day.
Most labs provide veterinary practices with supplies for submitting samples, free of charge