CAP TODAY Pathology/Laboratory Medicine/Laboratory Management
Anne Paxton
December 2013—Prompt reporting of critical laboratory results is considered an important patient safety goal. But for one of the most commonly performed tests, point-of-care glucose, there has been limited information about how critical results are handled. A new CAP Q-Probes study finds there is a great deal of variability. In addition to having widely differing critical result cutoff values, many laboratories are not repeating critical POC glucose test results for verification despite the relative high rate of erroneous results on first measurement.
Using data from 50 participating laboratories, the study, “Point-of-Care Glucose Critical Values,” evaluates the reliability of POC glucose results in the critical range as well as practices associated with notification. The study reports that while 92 percent of participants had a policy for repeat testing of critical POC glucose results, the median rate of critical values retested within 10 minutes was only 56 percent. Failing to repeat POC glucose tests with results in the critical range is not advisable, the study authors say. “Good laboratory practices should include repeating all critical POCG test results with verification criteria provided to test operators,” they write in their analysis of the data.
The study was undertaken, in part, because it’s been a Joint Commission patient safety goal for some time that critical results should be reported to the primary responsible provider, says study coauthor Ron B. Schifman, MD, chief of diagnostics for the Southern Arizona VA Healthcare System and vice chair of the CAP Quality Practices Committee.
“Laboratory medical technologists have plenty of experience handling critical values as a daily practice. Critical value policies and procedures for notification and turnaround time are well established in this setting,” he says. “But in most hospitals and health care settings, more glucose testing occurs outside the clinical laboratory at the point of care,” where much less is known about critical value practices.
CAP Q-Tracks studies have found that laboratories are very good at notifying providers of critical values when tests are performed in the core laboratory. Rates of almost 100 percent are common. “The question raised in this recent Q-Probes study deals with whether the same level of quality performance is seen with point-of-care testing,” Dr. Schifman says. The findings suggest not.
There are key differences between the testing sites, of course, because at the point of care, the patient’s direct caregivers can immediately evaluate the results in the context of the patient’s current clinical condition. “In the clinical laboratory, we don’t have the advantage of checking the patient to see if there are signs and symptoms of hyperglycemia or hypoglycemia that fit the test result. So the setting is different, but the principle is the same. If a patient has a critical value, the patient safety goals do not differentiate between places where the test is done.”