Thoracic ultrasound use in hospitalized and ambulatory adult patients: a quantitative picture

Abstract

Introduction and objectives: Thoracic ultrasound (TUS) has been established as a powerful diagnostic and monitoring tool in the Intensive Care Unit (ICU). However, studies outside the critical care setting are scarce. The aim of this study was to investigate the value of TUS for hospitalized or ambulatory community patients.

Materials and methods: This was a retrospective study conducted from 2016 to 2020 in the TUS clinic at Heraklion University Hospital. TUS examination was performed using a standard ultrasound machine (EUB HITACHI 8500), and a high-frequency microconvex probe (5-8 MHz). Patients had been referred by their primary physician to address a range of different questions. The various respiratory system entities were characterised according to internationally established criteria.

Results: 762 TUS studies were performed on 526 patients due to underlying malignancy (n = 376), unexplained symptoms/signs (n = 53), pregnancy related issues (n = 42), evaluation of abnormal findings in X-ray (n = 165), recent surgery/trauma (n = 23), recent onset respiratory failure (n = 12), acute respiratory infection (n = 66) and underlying non-malignant disease (n = 25). Pleural effusion was the commonest pathologic entity (n = 610), followed by consolidation (n = 269), diaphragmatic dysfunction/paradox (n = 174) and interstitial syndrome (n = 53). Discrepancies between chest X-ray and ultrasonographic findings were demonstrated in 96 cases. The TUS findings guided invasive therapeutic management in 448 cases and non-invasive management in 43 cases, while follow-up monitoring was decided in 271 cases.

Conclusions: This study showed that TUS can identify the most common respiratory pathologic entities encountered in hospitalized and community ambulatory patients, and is especially useful in guiding the decision making process in a diverse group of patients.

Keywords: Ambulatory; Diaphragmatic dysfunction; Malignancy; Pregnancy; Thoracic ultrasound.

Fig. 1

a Compressive atelectasis associated with large pleural effusion (PE). Colour doppler was used to depict the vessel inside the consolidated lung. b Right upper lobe tumor. Notice the augmented vascularization, the irregular boundaries and the complete loss of aeration. PE pleural effusion

Fig. 2

a Diaphragm dysfunction with atypical or paradoxical movement due to large pleural effusion (PE). Red dot line delineates the abnormally shaped diaphragm. Yellow and blue arrows indicate the reverse movement during inspiration. Note that when this sign is present, pleural fluid should be evacuated immediately. b Large pleural effusion (PE) and ascites. The blue arrow indicates the three-layer structure of the diaphragm floating in the fluid: a during expiration; b during inspiration, with abnormal shape; and c during deep inspiration, with the abnormal shape indicating paradoxical movement