key: cord-325352-k7aapnx3 authors: Manivel, Vijay; Lesnewski, Andrew; Shamim, Simin; Carbonatto, Genevieve; Govindan, Thiru title: CLUE: COVID‐19 Lung Ultrasound in Emergency Department. date: 2020-05-09 journal: Emerg Med Australas DOI: 10.1111/1742-6723.13546 sha: doc_id: 325352 cord_uid: k7aapnx3 nan Lung ultrasound (LUS) is a vital part of critical care evaluation of multiple lung pathologies, like pneumothorax, acute respiratory distress syndrome (ARDS), pulmonary oedema, interstitial lung disease (ILD) and pneumonia (1) . As SARS-CoV-2 infection causes interstitial pneumonitis, there is an extensive use of LUS in COVID-19 patients in China (2) and Italy (3) . Detection of COVID-19 by RT-PCR testing of nasopharyngeal swabs, considered as the gold-standard test, lacks sensitivity compared to CT chest, 59% vs 88% respectively(4). Ultrasound has an excellent correlation to CT chest findings (2) and could be an alternative to ionising radiation imaging (3) . Poor sensitivity of 59% for CXR to detect COVID-19 changes (5) and superiority of ultrasound in similar ILD (6), makes it an attractive imaging option. Performance of LUS at bedside also allows concurrent execution of clinical examination and lung imaging by the same clinician, expedites clinical decision making (7) . A step-by-step approach to safely performing LUS in Table 1 . We recommend chest be scanned systematically as 12 zones, six zones for the right lung (R1 to R6) and six zones for the left lung (L1 to L6, Figure 1 ). Scanning the posterior lung zones (R5, R6, L5, L6) will improve the sensitivity of LUS, as most changes are in the posterior lung (8) . For safe scanning, the patient to sit facing away from the clinician and posterior, lateral (R3, R4, L3, L4) and even anterior (R1, R2, L1, L2) zones scanned by the clinician positioned behind the patient. If the patient is in the supine position (unwell to move or sedated), the posterior lung zones replaced by scanning areas slightly posterior to the posterior axillary line. In our limited experience with COVID-19 patients, it takes less than 10 minutes to perform LUS, excluding cleaning time. Coronavirus being a lipid-based enveloped virus, is susceptible to low-level alcohol based disinfectant wipes (9) but strongly recommend involvement of the infection-control department and the ultrasound manufacturer in disinfection planning and guideline development. This article is protected by copyright. All rights reserved. An appropriately optimised image of a normal LUS will feature A-lines and few B-lines (<3 B-lines per intercostal space) and smooth thin pleural line (1) . Sonographic features of COVID-19 pneumonitis are (2) LUSS is a valid tool to assess regional and global lung aeration in ARDS (10, 11) and can be used in COVID-19 pneumonitis with several similar sonographic features(2). At each zone, LUSS points range from 0 to 3, with higher points allocated to severe lung changes ( Figure 2 ). Based on the total score from 12 lung zones, the severity classified as mild (score 1-5), moderate (>5-15) and severe (>15). A normal lung will have a total score of 0. A clinician's decision on the need for supplemental oxygen is a complex process, involving factors like oxygen saturation, work of breathing, respiratory rate and pre-existing medical conditions (i.e. COPD, heart disease). A single parameter like oxygen saturation or respiratory rate, may not represent real-time clinical practice. This article is protected by copyright. All rights reserved. CLUE protocol only provides a foundation, which is easy to use and flexible to accommodate complex clinical presentations. Some of the patients in the mild and moderate severity group could safely go home from the ED, provided a proper self-isolation facility, and adequate community follow-up ensured. In patients, who are depicted in cells with dotted borders in the table "CLUE protocol" in Figure 2 , consider in-hospital management if no pulse-oximetry monitoring or home-oxygen support provided. While Australia and New Zealand prepare for a figurative tsunami of highly infectious patients, we anticipate that a protocolised use of bedside LUS by emergency clinicians in COVID-19 patients could alleviate some of the radiological resource burden expected. Existing evidence supports LUS in COVID-19, but none has a clear objective scoring system or incorporates clinician's assessment in decision making. CLUE protocol aims to addresses this gap and provide the emergency clinician with an appropriate disposition plan. CLUE protocol will provide instant, objective information of the severity of the disease and may avoid further imaging like CXR and CT chest. Absence of ionising radiation with ultrasound makes it an ideal imaging modality for serial assessments, providing an objective measure of disease progression. Ultrasound performed by the treating clinician during the clinical examination may minimise the number of staff encounters, potentially minimise healthcare worker infection rate and cross-contamination among patients. We anticipate several limitations. Firstly, LUSS and CLUE protocol has never been tested for use in COVID-19 viral pneumonitis and currently a multicentre trial in Australia and New Zealand EDs in progress, to evaluate this scoring system. Secondly, LUS findings are not specific to COVID-19 and may not correlate to clinical outcome. Thirdly, using ultrasound in COVID-19 involves meticulous infection control practice. Finally, LUS requires an operator with a certain degree of training, and we strongly emphasise that beginners to LUS are not to train on these highly infectious patients. This article is protected by copyright. All rights reserved. Page 5 of 7 CLUE protocol which incorporates lung ultrasound scoring system and supplemental oxygen requirement at the time of examination, when performed by a trained emergency clinician, can help risk-stratify suspected COVID-19 patients. This protocol will aid the clinician to make rapid and appropriate bedside clinical decisions, potentially decrease reliance on chest X-rays or CT chest and aid disposition planning from the emergency department. This article is protected by copyright. All rights reserved. Thoracic ultrasonography: a narrative review Findings of lung ultrasonography of novel corona virus pneumonia during 2019-2020 epidemic Can lung ultrasound help critical care clinicians in the early diagnosis of novel coronavirus (COVID-19) pneumonia? Radiology Correlation of Chest CT and RT-PCR Testing in Coronavirus Disease 2019 (COVID-19) in China: A Report of 1014 Cases Clinical Characteristics of Coronavirus Disease 2019 in China Integrated Use of Lung Ultrasound and Chest X-Ray in the Detection of Interstitial Lung Disease COVID-19 outbreak: less stethoscope, more ultrasound. The Lancet A preliminary study on the ultrasonic manifestations of peripulmonary lesions of non-critical novel coronavirus pneumonia WFUMB Position Statement: How to perform a safe ultrasound examination and clean equipment in the context of COVID-19 Assessment of Lung Aeration and Recruitment by CT Scan and Ultrasound in Acute Respiratory Distress Syndrome Patients