Decentralized Coagulation

Coagulation

When it comes to a blood clot, every second matters. Clotting conditions like deep vein thrombosis (DVT) or venous thromboembolic (VTE) disorders pose significant concerns as morbidity and mortality from complications like a stroke or pulmonary embolism are a very real threat. Clinicians and physicians must be able to determine the clotting factors in a patient’s blood with speed and accuracy. In a recent interview with ADVANCE, American Society of Hematology (ASH) spokesperson Roy Silverstein, MD, professor and chairman of medicine at the Medical College of Wisconsin, senior investigator at the Blood Research Institute at the Blood Center of Wisconsin, discussed the benefits and limitations of point-of-care testing (POCT) in the diagnosis of coagulation disorders.

“In general, point-of-care testing has gotten a whole lot better now than it was 10 years ago, but still, it suffers by comparison to the laboratory-based test in terms of the accuracy and precision,” said Silverstein.

Presently, the most important and relevant POCT option available for coagulation diagnostics is the international normalized ratio (INR), measuring the blood’s ability to form a clot in a test tube. Utilizing an INR in blood from patients taking a commonly used anti-coagulant drug known as Warfarin (or Coumadin) prescribed to many patients with clotting disorders allows the physician to identify the most optimal dose to minimize a patient’s risk of either a blood clot or hemorrhage. Despite having been around for years, the INR remains something of a delicate procedure, with many different factors weighing in on the outcome – including the patient’s diet, ingested medicine, metabolism and the presence of vitamin K.

“If the blood is too thin, the patient is at risk of bleeding, and if it’s not thin enough, they’re at risk of having a blood clot – either a stroke or recurrence of their DVT or pulmonary embolism,” explained Silverstein. “So, although the drug has been around forever, it’s a little tricky to use.”

The INR offers a modern variation to traditional testing options, but standardized to fit the needs of any healthcare facility. Conventionally performed as a laboratory-based test, POCT options for INR save valuable time and offer the convenience of speed in critical situations – specifically the triage for stroke patients. The dosage for these medications must be adjusted frequently, however, and are monitored using INR.

“One can compare the blood test done in my hospital with the blood test done in your hospital, so that your doctor can adjust the dose not having to worry about where the test was done,” continued Silverstein. “It’s kind of a nuance, but it’s allowed [for] standardization.”

As testing technology continues to evolve, the rest of the healthcare industry is following suit. Although tried and true pharmaceutical options like Warfarin are still being used in the regulation of clotting disorders, new drugs are also being introduced to the market. For example, many pharmaceutical drugs in the newest generation of anticoagulants do not require INR testing. Despite the potential of POCT in coagulation, the technology is not without its limitations.

Because the INR test is a complex test that requires specialized training, the accuracy and precision of POCT options does not always match laboratory based methods. Laboratory tests are also regularly standardized and checked for quality, which is not always the case in POCT. In regards to home-based POCT options for monitoring blood tests, these may be subject to over- or under-testing due to human error and may not be available in a facility’s electron medical records (EMR).

“There’s an issue that sometimes occurs around point-of-care testing or over-testing – where patients sometimes get overly concerned and overly worried about managing their INR – and wind up doing the test too frequently and changing doses too frequently,” said Silverstein. “And, paradoxically, the regulation and the control of the dosing becomes worse instead of better.”

All the same, things are looking up for POCT coagulation methods as the industry moves forward. It’s no secret that, as the technology grows more readily available and reliable, POCT is changing the way clinical laboratory testing is performed. Instead of laboratory-based tests taking hours, POCT can produce results in minutes – cutting down on costs and improving patient experience in a facility. According to Silverstein, the speed and ease of the INR POCT tests offer benefits in healthcare facilities, different hospital departments and even the ambulance or patient’s home.

Michael Jones is on staff at ADVANCE.