Diagnostic Performance of 6-Point Lung Ultrasound in ICU Patients: A Comparison with Chest X-Ray and CT Thorax

Abstract

Objective: To evaluate the diagnostic performance of a rapid bedside 6-point lung ultrasonography (LUS) performed by an intensive care unit (ICU) physician for detection of four common pathological conditions of the lung, such as alveolar consolidation, pleural effusion, interstitial syndrome and pneumothorax, in critically ill patients and its comparison with bedside chest X-ray (CXR) and high-resolution computed tomography (CT) scan of the thorax. Volume of pleural effusion measured by LUS and CT thorax was also compared. Methods: This was a cross-sectional, observational study of 90 adult patients with an acute lung injury score of ≥1 admitted to the medical-surgical ICU. They were examined by CXR and 6-point LUS as per BLUE protocol at bedside, followed by CT thorax in the radiology department. Results: The sensitivity of 6-point LUS for detecting alveolar consolidation, pleural effusion, interstitial syndrome and pneumothorax was 76%, 88%, 83% and 89%, respectively, which was remarkably higher than that of CXR. The specificity of LUS was 100% for all pathologies, which was again notably higher than that of CXR except for interstitial syndrome for which it was 88.5%. Measurement of volume of pleural effusion by LUS was comparable and had a strong absolute agreement with CT thorax. Conclusion: 6-Point LUS can be a useful diagnostic tool and is better than CXR in diagnosing respiratory pathologies in critically ill patients. Owing to the comparable diagnostic performance of LUS and CT scan and with increasing evidence in favour of LUS, the requirement of CT thorax can be reduced. Radiation hazards associated with CXR and CT, as well as potentially risky transfer of patients to CT room, can also be minimised.

Lung ultrasound predicts clinical course and outcomes in COVID-19 patients

“…Pleural effusion was rare (n = 9, 8%). The median total lung score was 15, IQR [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Comparison of inter-observer variability for LUS score showed good agreement between measurements: mean difference 0.1 ± 0.05 points, r = 0.92, p = 0.36.…”

“…The use of lung ultrasound (LUS) as a diagnostic tool in critically ill patients, for assessment of response to treatment as well as for follow-up, has become common practice [6][7][8][9][10][11][12].Moreover, its use has been recommended as standard of care [13]. Findings on LUS correlate with clinical course similar to findings on high resolution CT [14,15] in various patient populations. Combining this powerful tool with bedside echocardiography allows rapid thorough assessment of cardiovascular and respiratory status of the patient and thus guidance of further treatment [16][17][18].…”

COVID‐US: A simplified approach to cardiopulmonary ultrasound in suspected and confirmed COVID‐19 patients in surge crisis

“…Pleural effusions are uncommon 2 . While chest X‐ray may be relatively insensitive to early lung pathology, 11 performing CT chests presents major logistic challenges due to the cardiorespiratory instability and difficulties to ensure adequate infection control and safety for the staff and other patients. Indeed, early reports from limited series suggest that lung ultrasound may perform similarly to the CT chest in the detection of COVID‐19 pulmonary involvement 12 .…”

Lung Ultrasonography and Cardiac Surgery: A Narrative Review

“…53 In this setting, LUS provides high accuracy, sensitivity, and specificity for diagnosing pleural effusion. 37,60 Exudate in the pleural cavity may cause fibrin to precipitate and form fibrinous layers, which appear as partitions and can lead to the development of pleural empyema if infection progresses. Fibrinous septa in the form of hyperechoic structures are visualized easily using ultrasonography (see Fig 5).…”