A New Scoring Model to Diagnose COVID-19 Using Lung Ultrasound in the Emergency Department

Patients:

The study recruited all patient with pulmonary symptoms and presented to ED between 27th March 2020 and 17th May 2020. Exclusion criteria were (i) patients with congestive heart failure (n= 7), (ii) patients with known interstitial lung fibrosis (n= 4), and (iii) patients with poor echo-window (n= 4). Patients were seen first at ED where they underwent the required investigations and then classified. Patients were questioned about symptoms suspecting COVID-19 infection. Those who met the suspected clinical and investigational criteria were given a standard mask and were rapidly transferred safely to a separate waiting and isolation area with available infrastructure and tools for hand and respiratory hygiene practice. If the patient was proved to be positive for COVID-19, he was sent to quarantine. For negative patients, they were admitted to intermediate or ICU according to their clinical status. All recruited patients underwent the followings: complete blood count (CBC), arterial blood gas (ABGs), RT-PCR assay to detect COVID-19, chest X-ray, chest CT, LUS, and echocardiography (according to its availability, with precautions for the operators and the probe similar to those exerted to LUS).

LUS examination:

Two trained medical personnel, one ICU physician and one ICU nurse, entered the isolation room respecting all the preventive measures for respiratory, droplet, and contact isolation provided by the world health organization for the COVID-19 outbreak. The ultrasound probe and the tablet were put in two different sterile, plastic probe and tablet covers. Imaging was performed using a curvilinear probe (2-5 MHz) with different devices according to the availability in each centre. Six-point LUS (three in each hemithorax) was performed as described in the bedside lung ultrasonography in emergency (BLUE) protocol [13].

Statistical analysis: