key: cord-0722346-eey039mz
authors: Vetrugno, Luigi; Bove, Tiziana; Orso, Daniele; Barbariol, Federico; Bassi, Flavio; Boero, Enrico; Ferrari, Giovanni; Kong, Robert
title: Our Italian experience using lung ultrasound for identification, grading and serial follow‐up of severity of lung involvement for management of patients with COVID‐19
date: 2020-04-15
journal: Echocardiography
DOI: 10.1111/echo.14664
sha: 71762c0d8d80473a061c805686e6885a9afb93e9
doc_id: 722346
cord_uid: eey039mz

Lung ultrasound (LU) has rapidly become a tool for assessment of patients stricken by the novel coronavirus 2019 (COVID‐19). Over the past two and a half months (January, February, and first half of March 2020) we have used this modality for identification of lung involvement along with pulmonary severity in patients with suspected or documented COVID‐19 infection. Use of LU has helped us in clinical decision making and reduced the use of both chest x‐rays and computed tomography (CT).

During this ongoing battle against the novel COVID-19, LU has quickly been recognized as a tool for diagnosis and monitoring of lung involvement severity. 1 A normal LU demonstrates what are termed A lines. These are a repetition of the pleural line at the same distance from skin to the pleural line. This is indicative of air below the pleural line, corresponding to the parietal pleura. Lines may be complete or partial (Figure 1 , Movie S1).

Demonstration of B lines are described as hyperechoic laser-like artifacts that resemble a "comet tail" (Figure 2 ). These arise from the pleural line and move in concert with a sliding lung. The A lines are generally not present. B1 lines are associated with an interstitial syndrome and diminished lung aeration. B2 lines are confluent lines appearing as a "white lung" (called also glass-rockets), equivalent to computed tomography (CT) ground-glass opacities. This suggests a more severe loss of lung aeration (Movies S2 and S3).

Lung consolidations (C) are associated with hepatization of lung parenchyma with or without air bronchograms, and suggest major loss of lung aeration (atelectasis vs pneumonia; Movie S4).

We have not identified an ultrasound appearance that would be pathognomonic of COVID-19. 2

The lung ultrasound score (LUS) has been shown to be a useful tool in intensive care (ICU) patients with adult respiratory distress syndrome (ARDS). We feel that this has been of value in assessing severity of lung involvement with COVID-19. 3, 4 One may perform a topographic analysis of the underlying lung regions daily without moving the patient. A scan of the three dif- Thus, a LUS of 0 is normal, and 36 would be the worst.

LUS score can be used to follow the clinical patient trajectory in which an increased score means decreased lung aeration, while on the contrary, a decrease in score means an increase in lung aeration limiting the need of chest x-ray and CT scan. 2 An experienced sonographer can do this examination within 5 minutes, while brief training and about 25 supervised exams seem to be sufficient to achieve a basic ability to perform the study. 5 A prior study showed the impact of LU to affect clinical decisions in up to 50% of intensive care unit patients. 6 

Although a patient's clinical context allows for an improved pretest estimate of COVID-19 lung involvement, it appears that LU may serve as a bedside tool to improve evaluation of lung involvement, and also reduce the use of chest x-rays and CT. 7 In addition, several intensive care units following central venous line positioning with ultrasound, have not been routinely obtaining post insertion chest

x-rays. 8, 9 While the ability of a chest x-ray to discriminate a bacterial pneumonia from a non-bacterial infection is no more than 60%, 10 LU has a higher sensitivity (80%). 11 Specific comparison studies in critically ill patients regarding viral pneumonia, however, are few. 12 

During this pandemic we have used LU in patients suspected or diagnosed with COVID-19. Application of LUS has allowed for identification of patients with lung involvement and severity. In addition, serial studies help us follow for progression or regression of disease.

With the application of LU we have had a noted reduction in use of chest x-rays and CT scans during this pandemic, helping us to make care and management of our patients a little more efficient. 

Correlation between transthoracic lung ultrasound score and HRCT features in patients with interstitial lung diseases

Prognostic value of extravascular lung water assessed with lung ultrasound score by chest sonography in patients with acute respiratory distress syndrome

Training for lung ultrasound score measurement in critically Ill patients

Impact of lung ultrasound on clinical decision making in critically ill patients

Could the use of bedside lung ultrasound reduce the number of chest x-rays in the intensive care unit? Cardiovasc Ultrasound

Ultrasound to detect central venous catheter placement associated complications: a multicenter diagnostic accuracy study

Lung ultrasound and COVID-19 "pattern": not all that glitters today is gold tomorrow

Accuracy of radiographic differentiation of bacterial from nonbacterial pneumonia

The usefulness of lung ultrasound for the aetiological diagnosis of community-acquired pneumonia in children

Early recognition of the 2009 pandemic influenza A (H1N1) pneumonia by chest ultrasound