Lung Ultrasound Abnormalities in Patients Without Pulmonary Pathology Prior to Surgery

Background: The occurrence of lung ultrasound abnormalities in patients without lung disease remains uncertain, while patients with respiratory disease often exhibit such abnormalities.

Objectives: The primary aim was to identify pathological ultrasonographic pulmonary findings and their correlation with baseline diseases and static lung compliance in patients without any pre-existing respiratory conditions.

Methods: This prospective observational study enrolled a series of surgical patients with no history of pulmonary pathology (n = 104). Baseline diseases and patients' physical status classification, based on the American Society of Anesthesiologists (ASA), were documented by reviewing medical records. Prior to surgery, a lung ultrasound was performed to assess pulmonary changes. During surgery with general anesthesia, static lung compliance was measured. The Spearman correlation coefficient was employed to determine the correlation between the two variables.

Results: Twenty-four patients (23.07%) exhibited 1 - 2 B-lines in certain lung fields. Seven patients (6.7%) had an ultrasound B-line score > 0 (indicating ≥ 3 B-lines). Among these patients, the average number of lung fields with ≥ 3 B-lines was 3.71 ± 2.43. Patients with systemic diseases (ASA ≥ 2) displayed a higher number of B-lines compared to ASA I patients (P-value = 0.039). Pleural irregularities were found in 10 patients (9.6%), while atelectasis and pleural effusion were observed in five (4.8%) and four (3.8%) patients, respectively. The mean lung compliance value was 56.78 ± 15.33. No correlation was observed between the total score of the B-lines and lung compliance (Spearman's correlation: rho = -0.028, P-value = 0.812).

Conclusions: Patients without pulmonary pathology may exhibit ultrasound pulmonary abnormalities, which tend to increase with higher ASA scores and do not appear to have a correlation with static lung compliance.