To be confident in what you tell your clients, you’ve got to have confidence in the laboratory doing your blood work, whether it’s a full-scale reference lab or a bench-top machine in your clinic. While an in-house blood analyzer can be a time-saving, convenient practice tool, in many cases even the finest equipment is no substitute for human knowledge and experience, veterinary clinical pathologists say. And when you have a shadow of a doubt about your results, it pays to double-check.
“In-house laboratory machines can definitely improve turnaround time,” said Leslie Sharkey, DVM, Ph.D., a diplomate of the American College of Veterinary Pathology (Clinical Pathology). “Pre-anesthetic blood work for routine or elective procedures in otherwise relatively healthy animals is one of the best applications of these machines.”
Dr. Sharkey, an associate professor at the University of Minnesota’s College of Veterinary Medicine, is president of the American Society for Veterinary Clinical Pathology.
In emergency cases, the quick results offered by a lab machine across the room are a major asset, added Kristen Friedrichs, DVM, Dipl. ACVP (Clinical Pathology), assistant professor at the University of Wisconsin School of Veterinary Medicine.
“If we…focus on which results are needed immediately to make clinical treatment decisions, there are several biochemical abnormalities that constitute emergencies,” said Dr. Friedrichs, who serves on the society’s Quality Assurance and Laboratory Standards Committee.
“These include marked hypo- or hyperkalemia, hypocalcemia, hypoglycemia and a few others. Being able to get these results in-house and monitor them may mean the difference between life and death for a patient,” she said. “Clinics that do a lot of emergency work are more likely to need in-house testing capabilities, and often a more sophisticated laboratory with dedicated personnel.”
Point-of-care blood work results allow the veterinarian to perform additional diagnostics or dispense proper medication while the client is in the building, which vastly improves compliance with the treatment plan, noted Craig Tockman, DVM, director of professional services for Abaxis North American Animal Health of Union City, Calif.
“The delay in processing certain tests, whether it is four hours or 24 hours, can make certain results simply unreliable due to sample degradation,” Dr. Tockman said. “Glucose, for example, is extremely inaccurate when the sample sits for any extended period. If the sample is not properly centrifuged or if hemolysis occurs in transit, many analytes can be affected, such as alkaline phosphatase (ALP) or potassium.”
That being said, the extremely abnormal hematological or serum chemistry values registered by very sick animals are the numbers veterinarians must evaluate most critically, Sharkey said.
“The problem is that the accuracy of these (in-house) machines can diminish when significant laboratory abnormalities are present,” Sharkey said, “so they are less reliable in sick patients, and the results may not be comparable to the gold standard reference analyzers.
“For me, with in-house lab machines, hematology analyzers are less accurate than chemistry analyzers,” Sharkey continued. “It’s always important to keep in mind that there is a lot of information the machine cannot give you, so microscopic evaluation of a blood film by an experienced and well-trained individual is always a necessary component of a complete hematologic evaluation.”
While it could be tempting to skip evaluating a blood smear if the analyzer cell counts are normal, you risk missing critical information, Sharkey said.
“Machines can give people a false sense of security. They don’t read Anaplasma, toxic changes or left shifts,” she said. “An in-house machine is really no substitute for doing microscopy.”
Choosing in-house blood analyzing equipment for a veterinary practice should be based on the caseload, personnel resources and costs involved, noted Bente Flatland, DVM, MS, Dipl. ACVP, and a diplomate of the American College of Veterinary Internal Medicine. She is an assistant professor at the University of Tennessee’s College of Veterinary Medicine.
“Realities that must be considered are that maintaining an in-clinic laboratory requires a dedicated budget, a commitment to quality management, dedicated personnel who are appropriately trained, appropriate physical space and time,” Flatland said.
Veterinarians considering this major capital investment need to include funding to maintain reagents, control materials and supplies; training and continuing education for staff members; and time involved in writing and maintaining standard operating procedures, running controls and interpreting the data, instrument maintenance and inventory, she added.
“Practitioners need to attempt to accurately estimate their work flow and determine if they have the trained personnel available to implement their plans,” said Kendal Harr, DVM, MS, Dipl. ACVP. “Estimated numbers of planned samples change the type of and specific instruments that they should be investigating for purchase. In a small, low-volume practice, it is likely that the majority of laboratory analysis is more cost-effective when sent to a reference lab.”
Dr. Harr, who owns URIKA LLC, a pathology consulting consortium, chairs the ASVCP’s Methods Validation Subcommittee.
Expired, unused reagents are wasted money to a veterinary business, Sharkey said.
“If the reagents are not stored correctly, they can degrade and not work, which can also be costly,” Sharkey said.
“The most important thing to keep in mind is that laboratory work requires a serious commitment of time and resources,” Sharkey added. “It’s fine to do lab work, but it’s a commitment. Buying the machine doesn’t guarantee that you know how to use it. I think that as all this technology becomes available, you want to ask: Is this going to be an area of emphasis for me, or is it something best outsourced, to make better use of my practice’s time and strengths?”