Lung ultrasound a promising tool to monitor COVID-19 lung changes after discharge

Lung ultrasound findings significantly improved from hospitalization to 2 to 3 months after discharge in COVID-19 survivors, according to results of a study published in Respiratory Medicine.

“Several studies have ... assessed the dynamic changes in lung ultrasound findings during a COVID-19 infection and found that lung ultrasound can be used to monitor disease progression during hospitalization,” Caroline Espersen, MD, researcher in the department of cardiology at Herlev and Gentofte Hospital at the University of Copenhagen in Denmark, and colleagues wrote. “However, whether the lung ultrasound findings detected during the initial COVID-19 infection resolve or persist after hospital discharge is less well investigated.”

The prospective, longitudinal study enrolled 71 adults with COVID-19 (mean age, 64 years; 61% men) in non-ICU hospital units. All patients underwent eight-zone lung ultrasound and blood sampling during hospitalization and again after discharge at 2 to 3 months’ follow-up. Follow-up lung ultrasound was performed a median of 72 days after the initial ultrasound, which was performed a median of 3 days after admission.

One-quarter of patients had acute respiratory distress syndrome, 46% had hypertension and 19% had diabetes.

Overall, 87% of patients had pathologic lung ultrasound findings in one or more zones at baseline compared with 30% during follow-up (P< .001). The proportion of patients with confluent B-lines in at least one zone also decreased from 25% at baseline to 0% at follow-up (P < .001). Researchers reported a decrease from hospitalization to follow-up in the total number of B-lines (median, 17 vs. 4; P < .001) and lung ultrasound score (4 vs. 0; P < .001).

On follow-up lung ultrasound, 28% of patients had three or more B-lines in at least one zone. However, among the 17 patients with ARDS during hospitalization, there was a higher number of B-lines (median, 5 vs. 3), and 47% had three or more B-lines in at least one zone compared with 22% of patients without ARDS.

“Although lung ultrasound is useful for monitoring changes in lung density after discharge in patients hospitalized for COVID-19, the long-term evolution in lung density as well as the association with pulmonary function and symptoms should be investigated further in future longitudinal follow-up studies,” the researchers wrote. “Lung ultrasound could potentially be implemented in a strategy to characterize the longer-term effects of COVID-19 infection on lung density.”