Medical students are accurate in interpreting the presence of pathologic interstitial edema on focused lung ultrasound compared to expert reviewers.

Background: Over the past two decades, studies have demonstrated that lung ultrasound is useful in diagnosing alveolar interstitial syndrome, which is seen in patients with decompensated congestive heart failure (CHF).

Methods: We studied medical students performing lung ultrasound on patients admitted to the hospital with a presumed diagnosis of decompensated CHF in a prospective convenience observation study. Two ultrasound fellowship-trained emergency medicine attendings independently reviewed the lung ultrasounds at a later date, blinded to the students' interpretation and other clinical information, to confirm ultrasound findings and assess for inter-rater reliability of the lung ultrasound using intraclass correlation coefficients (ICCs).

Results: Thirty-six patients were enrolled in the study resulting in 653 unique lung zones scanned. The zones were imaged and classified as being normal (B-lines < 3) or pathologic (B-lines ≥ 3). The novice scanners' interpretation was compared to expert reviews using ICCs. The ICC was 0.88, with a 95% confidence interval of 0.87 to 0.90, for all lung zones scanned.

Conclusion: There was almost perfect agreement between novice practitioners and experts when determining the presence of pathologic B-lines in individual patients.