Long Covid Research Uncovers Lung Defect that Could Explain Dyspnea

Long-term Covid patients’ lungs have been found to contain abnormalities, which could explain why some people have dyspnea long after their first infection.

A modest pilot research in the United Kingdom reveals that certain persons with lengthy Covid may have hidden lung harm. The researchers employed a unique xenon gas scan method to detect lung abnormalities that were missed by standard scans, the BBC reported.

They focused on 11 people who did not require hospitalization when they first contracted Covid but developed long-term dyspnea afterward. To corroborate the findings, a larger, more extensive investigation is being conducted. The research relies on a previous study that looked at persons who had been hospitalized with Covid. Long Covid is a term that describes a slew of symptoms that persist for weeks after a coronavirus infection and can’t be explained by anything else.

The researchers examined the scans and other lung-function testing in three groups of patients from Oxford, Sheffield, Cardiff, and Manchester, reports said.
During a magnetic resonance imaging (MRI) scan, all subjects inhaled xenon gas using the innovative method.

Scientists were able to “see” how successfully the gas went from the lungs into the blood stream – a vital stage in carrying oxygen across the body – because it behaves similarly to oxygen and can be followed visually during scans. Gas transfer was observed to be less effective in the majority of persons with lengthy Covid than in healthy controls. Similar anomalies were seen in those who had been admitted to the hospital for Covid.

Dr. Emily Fraser, the study’s lead researcher and a lung expert, said it was difficult to see people in clinic and not be able to explain why they were out of breath. X-rays and CT scans frequently reveal no abnormalities. More work would be required to clarify the clinical significance of the findings, she added, including how the apparent abnormalities relate to breathlessness.

The most recent study, which intends to enroll 400 people, uses a specialized MRI imaging process that involves patients inhaling xenon gas while reclining in a scanner. As the gas goes through the lungs and into the circulation, it can be monitored to see how well the lungs are operating. CT scans, on the other hand, only reveal the lungs’ structure.

The study looked at three groups: patients with long Covid who had normal CT scans, those who had been hospitalized with Covid for more than three months but weren’t experiencing long Covid, and a healthy control group. The preliminary findings, which were published on the bioRxiv pre-print server, demonstrate that these long Covid patients have “substantially reduced gas transmission” from the lungs to the circulation, even when other tests are normal.
Similar anomalies were discovered in Covid patients who had been admitted to the hospital with a more serious illness.

These preliminary findings are very fascinating, according to Dr. Louise Sigfrid, a public health specialist at the University of Oxford, and they are consistent with other emerging data on lung perfusion deficits following Sars-CoV-2 infection in adults and adolescents.