Background
Transthoracic ultrasound (TUS) can potentially give important complementary
information in particular conditions like bedside rapid diagnostic evaluation of
dyspneic patients who commonly present to emergency (ER) units.
Objective
Assessing the significance and diagnostic utility of B-lines and pleural line
abnormalities detected on TUS among patients presented to the ER unit for the
assessment of dyspnea against high-resolution computed tomography findings.
Patients and methods
A prospective observational study including 240 consecutive patients was
conducted. TUS was done for patients presenting to the ER for the assessment
of dyspnea. B-lines and the pleural line were evaluated by a linear and convex
transducers. Sonographic findings were reported against high-resolution computed
tomography findings, which was considered the gold standard.
Results
Slightly rough, fringed, irregular, interrupted, wavy, coexistence of more than one
abnormal type of pleural line were detected in 30.8%, 35.4%, 19.2%, 17.9%, and
30% of cases, respectively. Warrick score classified patients with interstitial lung
disease to mild (44.6%), moderate (36.3%), and severe (19.2%). Diffusing capacity
for carbon monoxide (DLCO% predicted) and total lung capacity (TLC% predicted)
predicted showed negative correlation with Warrick score (r=-0.66, r=-0.48
respectively, P≤0.001 for both) and positive correlation with distance between B
lines (r=0.31 and 0.30 respectively, P≤0.001 for both). Warrick score at a cutoff
more than 7 showed 96.3% sensitivity and 64.3% specificity. Distance between B
lines at cutoff more than 3 mm had 100% sensitivity and 40.4% specificity. Cutoff
more than 3 for B lines number/scan showed 92.6% sensitivity and 31% specificity.
Pleural thickness at cutoff more than 2 mm showed 100% sensitivity and 34%
specificity. Abolished lung sliding showed 96.3% sensitivity and 50% specificity.
Conclusion
TUS is an important tool for the diagnosis and assessment of pulmonary disorders.
B-lines number and distance, pleural line abnormalities, lung sliding, and pleural
thickness added diagnostic value for the ER assessment of dyspneic patients.