Checking for These 4 Symptoms May Help GPs More Accurately Diagnose Pneumonia

The results of a new study reveal that combining 4 simple non-invasive tests with a clinical examination could help general practitioners (GPs) diagnose pneumonia and therefore, help stave off unnecessary prescriptions for antibiotics.

An infection of the lungs that can result in mild to severe illness, pneumonia can be caused by viral, bacterial, or fungal pathogens. In a perfect world, treatments for infections would match the cause of the infection; however, many times doctors choose to treat infections empirically because it can take days for lab results to come back indicating the true cause of an infection. Point-of-care tests to help practitioners determine whether infections are bacterial or viral are already available; however, not all general practitioners have access to these tests. In their absence, researchers from the University of Southampton, in England, have learned that a few noninvasive tests may go a long way in helping GPs differentiate pneumonia—a more serious infection that typically warrants antibiotics—from other, less serious respiratory infections that may not require them.

For the study, published in the European Respiratory Journal, Michael Moore, MD, professor of primary care research at the University of Southampton, and his colleagues, “studied 28,883 patients who had visited GPs at 5,222 different surgeries across the United Kingdom with signs of an infection in the lungs or airways, such as a cough,” according to a press release on the research. The investigators collected information on the patients’ symptoms, as well as tests they underwent, and any treatments they received. In addition, the patients were monitored for 30 days after their visit. “A total of 720 patients in the study went on to have a chest x-ray and of these, 115 were found to have pneumonia,” according to the press release.

Upon reviewing the data, the investigators found that 4 distinct signs and symptoms were more common in those patients who had pneumonia. These 4 symptoms were:

1. Temperature higher than 100.4°F
2. Crackling sounds in the lungs
3. Pulse rate >100 bpm
4. Blood oxygen saturation <95%

About 86% of the patients who had pneumonia exhibited 1 or more of the 4 symptoms.

Of interest is the fact that blood oxygen levels were able to aid in diagnosing pneumonia. Although pulse oximeters have been introduced into GP offices, according to the press release on the study, until now there has not been any convincing evidence that they may help diagnose pneumonia. "This is the first large study to look at whether oxygen saturation might indicate pneumonia,” said Dr. Moore in the press release. “The results do support using pulse oximetry in assessing patients in primary care. We can't rule out that widespread use might result in more patients being referred to hospital. For this reason, it should be considered by GPs in conjunction with a clinical examination and other factors."

The investigators note that 1 limitation of their study is the fact that they relied on x-rays to confirm the pneumonia diagnosis. In total, relatively few of the patients had an x-ray, and so, some of the patients with milder cases of the infection may have been missed.