Pressure’s On To Monitor Blood Pressure
Blood pressure monitoring, long a staple in preventive human medicine, is increasingly being incorporated into veterinary practices to enable earlier detection of many common diseases in pets.
Keven Gulikers, DVM, Dipl. ACVIM, of the Center for Veterinary Specialty Care in Carrollton, Texas, notes that blood pressure readings are becoming a more integral part of anesthetic monitoring.
“And more family veterinarians are evaluating blood pressures in patients with diseases that can cause hypertension, such as chronic renal failure and Cushing’s disease,” he adds.
Indeed, Nora Matthews, DVM, Dipl. ACVA, professor at Texas A&M University’s College of Veterinary Medicine, says regular blood pressure monitoring is commonly used to follow chronic diseases in pets. It is increasingly being incorporated into standard pet wellness programs. Thus, she notes, the cost of a blood pressure monitor is nominal when used on most patients in the practice.
Andrew Schultz, director of veterinary monitoring and critical care for Sharn Veterinary Inc. of Tampa, Fla., agrees that acceptance and adoption of routine blood pressure screening is increasing, but he says it is still far lower than it should be.
“Just think what happens every single time you see your doctor. They weigh you and take your blood pressure,” he says. “There are good medical reasons for this.”
Schultz says anecdotal evidence suggests that a large percentage of veterinary practices do not offer routine blood pressure screening.
“However, in the upper echelon of vet practices, those that are AAHA certified, the trends are much clearer and better,” he says.
“According to (the AAHA’s) biannual Veterinary Fee Reference guide, the number of members who offer diagnostic blood pressure evaluation has grown from less than 50 percent in 2005 to 72 percent in 2007.”
Anthony Carr, DVM, Dipl. ACVIM, professor of small animal clinical sciences at Western College of Veterinary Medicine in Saskatoon, Canada, says the increased interest in blood pressure monitoring in the veterinary industry is partially because new graduates are routinely trained to take such measurements.
“In addition, it has become clear to more and more veterinarians how much sense measuring blood pressure makes,” he says. “Technology has gotten better and made it easier to measure pressures.”
Not a Tough Sell
Schultz says veterinarians might be surprised at how quickly clients embrace blood pressure monitoring for their pets.
“Most of their clients probably already believe that the practitioner is monitoring their pets’ blood pressure and would certainly buy in to the addition of that service in light of what they expect from their own doctors,” he says.
Veterinarians can use blood pressure monitoring to better their bottom lines. “According to the 2007 AAHA fee reference guide, the median charge (for blood pressure monitoring) is $25, with most survey respondents charging between $20 and $35,” Schultz says. “It is easy to calculate the payback period on an investment in such equipment.”
William Tavolacci, LVT, of New York City’s Animal Medical Center says explaining the importance of blood pressure monitoring to clients is easy. “The difficulty lies in trying to justify the additional cost to a client,” he says. “After all, the client’s blood pressure is taken by their doctor for no extra cost during their yearly checkup.”
A good way to handle it, Tavolacci says, is “to include a blood pressure check in all senior exams, encourage senior exams every six months, and charge 75 to 100 percent of the regular exam fee.”
Ailments that can be detected early because of high blood pressure include chronic renal failure, Cushing’s disease, certain adrenal tumors and heart disease, says Dr. Gulikers, of the Center for Veterinary Specialty Care. “More importantly, their progression can be altered and more serious consequences such as a cerebral vascular accident, or stroke, can hopefully be avoided,” he says.
Older cats, in particular, should have blood pressure measured routinely, Dr. Carr says. “In old cats, there is pretty good evidence that they have idiopathic hypertension—that is, blood work is normal and yet they are hypertensive. Underlying it is probably early renal issues, but we would not be capable of picking up on this with the tests we routinely do. As such, I think it is wrong to only measure blood pressure in animals with diseases known to cause hypertension.”
Of course, Carr notes, veterinarians should not overinterpret blood pressure readings.
“Certainly, many of the diseases we see are associated with hypertension—Cushing’s, hyperthyroidism, kidney disease—and ideally we would find these with blood and urine tests rather than skipping these to just do blood pressure,” he says. “In some instances, though, it is easier to motivate the owner to do a blood pressure. If it comes up abnormal, there is greater motivation to run blood work to try and find a cause.”
Also, Carr notes, veterinarians must rule out “white coat” hypertension, or high readings resulting from the stress of the clinic setting.
Carr says he finds it useful to send pet owners home with a blood pressure monitor so they can take the reading in a more relaxed setting.
“They bring the unit to me and I can download the graphics to my computer and see which ones are real,” he says. “This has gone a very long way toward eliminating white-coat hypertension as a major issue in my practice.”
Choosing a Method
When it comes to monitoring, veterinarians have multiple choices, and each has advantages and disadvantages.
“Although direct arterial monitoring is invasive,” Gulikers says, “it is the most accurate method available but relies on advanced nursing skills to place the catheter in the appropriate artery. It is certainly indicated in many complicated or advanced surgical cases, such as adrenal gland tumor removal.”
Non-invasive monitoring methods include oscillometric and Doppler, Gulikers notes. “The former is very convenient but has lower accuracy, while the latter is less convenient but much more accurate,” he says. “As an internist, I prefer Doppler monitoring for many of the patients I see as it is very reliable when using a trained staff.”
Not all veterinarians share Gulikers’ preference. “I prefer oscillometrics over Doppler, since Doppler is notoriously user-dependent,” Carr says. “With the newer oscillometrics, blood pressure can be measured in most animals.”
Indeed, beyond cats and dogs, blood pressure monitoring can be accomplished on many exotic and pocket pets, including ferrets, rabbits and some birds, Sharn Veterinary’s Schultz says. “Using non-invasive blood pressure, practitioners are only limited by cuff size and the upper range of the heart rate specified by the device,” he says.
Schultz notes that not all oscillometric devices are the same, and it all comes down to the algorithms in the monitor. “Practitioners should look for validated studies in peer-reviewed sources, should check with colleagues and their alma maters to discover what others are using successfully, especially in cats,” he says.
Tavolacci says the most interesting new blood pressure technology is the high-definition oscillometry, or HDO, system. “As with all new technology, the cost is high,” he says. “If this is what it appears to be, it will bring veterinary medicine more accurate information.
“One of the greatest challenges in bringing blood pressure monitoring to the general practice veterinarian is reliability,” he adds. “If HDO can bring reliability and accuracy to veterinary blood pressure, then all we have left to do is find a way to keep our patients calm and relaxed in a veterinary hospital.” <HOME>
This article first appeared in the September 2009 issue of Veterinary Practice News