Conference Coverage

Point-of-care test for respiratory viruses lowers antibiotic use

Routine testing in the ED is advocated



PARIS – Using a point-of-care test for viral pathogens, hospital admissions were avoided in about a third of emergency department patients with suspected respiratory infection when other clinical signs also suggested a low risk of a bacterial pathogen, according to a single-center experience presented at the annual congress of the European Respiratory Society.

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“We found that when patients had point-of-care respiratory viral testing soon after they were admitted to the emergency department, we were able to reduce unnecessary admission and improve bed flow in our center,” reported Kay Roy, MBBS, consultant physician in respiratory medicine, West Hertfordshire (England) Hospital NHS Trust.

In a protocol that was launched at Dr. Kay’s institution in January 2018, the point-of-care viral test was combined with other clinical factors, particularly chest x-rays and elevated C-reactive protein (CRP), to determine whether patients had a viral pathogen and whether they could be discharged without antibiotics.

“Clinical judgment will always be required in individual patient decisions regarding antibiotic avoidance and early discharge,” Dr. Roy maintained. “But the point-of-care viral assay can be integrated into a strategy that permits more informed and rapid decision-making.”

This assertion is supported by the experience using a protocol anchored with the point-of-care viral test over a 4-month period. During this time, 901 patients with respiratory symptoms suspected of having a viral etiology were evaluated with the proprietary point-of-care device called FilmArray (bioMérieux).

From a sample taken with a nasopharyngeal swab, the test can identify a broad array of viruses using polymerase chain reaction technology in less than 45 minutes. However, the ED protocol for considering discharge without antibiotics requires additional evidence that the pathogen is viral, including a normal chest x-ray and a CRP less than 50 mg/L.

Of the 901 patients tested, a substantial proportion of whom had chronic obstructive pulmonary disease (COPD) or asthma, 507 (56%) tested positive for at least one virus, including influenza, rhinoviruses, coronaviruses, and adenovirus. Of these, 239 had normal chest x-rays and CRPs less than 50 mg/L. Because of the severity of symptoms or other clinical considerations, 154 patients were admitted, but 85 (36% of those meeting protocol criteria) were discharged without an antibiotic prescription.

“Antibiotics were continued in 90% of the patients who had an abnormal chest x-ray and abnormal CRP,” Dr. Roy reported. However, an objective strategy that permits clinicians to discharge patients at very low risk of a bacterial infection has many advantages even if it applies to a relatively modest proportion of those tested, according to Dr. Roy.

“Each respiratory admission can cost around [2,000 pounds] at our center,” reported Dr. Kay, referring to a figure equivalent to more than $2,600. In addition, she said that avoiding hospitalization frees up hospital beds and facilitates improved antimicrobial stewardship, which is vital to stem resistance.

Avoiding antibiotic use in patients with viral respiratory infections also is relevant to improved antibiotic stewardship in the community. For this reason, a randomized trial with a similar protocol involving the point-of-care viral test is planned in the outpatient setting. According to Dr. Roy, this will involve a community hub to which patients can be referred for testing and clinical evaluation.

“We hope that the quality of care can be improved with the point-of-care test for respiratory viruses as well as helping to reduce antibiotic resistance,” Dr. Roy said.

This approach is promising, according to Tobias Welte, MD, of the department of respiratory medicine at Hannover (Germany) Medical School, but he cautioned that it is not a standard approach.

“The protocol described by Dr. Roy will have to be compared to guidelines and recommended best clinical practice to confirm its usefulness,” he said, while conceding that any strategy that reduces unnecessary hospitalizations deserves further evaluation.

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