Aims

Ultrasound is a valuable diagnostic tool in the diagnostic work-up of dyspnea and can identify even small pleural effusions. Incorporating Shear Wave Elastography (SWE) represents a possible tool in stratifying pleural effusions by risk of underlying malignancy. No previous studies have been conducted in an emergency department (ED), where it might have a clinical impact by hastening referral for diagnostic work-up of underlying malignancy. The aim of this study was to appraise the diagnostic accuracy of ultrasonographic findings associated with thoracic malignancy, as well as calculating optimal cut-off values for SWE in this regard.

Methods

Patients with unilateral pleural effusion of unknown origin were included in the ED and subjected to a Focused Lung Ultrasound (FLUS) scan during their first 48 hours after admittance. Two index tests were applied: i) traditional 2D FLUS examination registering presence of diaphragmatic noduli, pleural thickenings and other findings associated with malignancy, and ii) a SWE examination of different Regions of Interest. Reference test was defined as subsequent diagnosis of malignant pleural effusion (MPE) in the three months following inclusion.

Results

39 patients were included. The 2D index test yielded a sensitivity of 28.57% (95%CI 3.67-70.96%) and a specificity of 90.62% (95%CI 74.98%-98.02%). The SWE max of intercostal space yielded a sensitivity of 100% (95%CI 47.82-100%) and a specificity of 59.09% (95%CI 36.35%-79.29%).

Conclusion

FLUS with integrated SWE may aid in identifying MPE's and improving referral to diagnostic work-up of underlying malignancy. Larger adequately powered studies are warranted.