Appropriateness of lung ultrasound for the diagnosis of COVID-19 pneumonia

Background Chest radiography (CXR) and computerized tomography (CT) are the standard methods for lung imaging in diagnosing COVID-19 pneumonia in the intensive care unit (ICU), despite their limitations. This study aimed to assess the performance of bedside lung ultrasound examination by a critical care physician for the diagnosis of COVID-19 pneumonia during acute admission to the ICU. Method This was an observational, prospective, single-center study conducted in the intensive care unit of Adan General Hospital from April 10, 2020, to May 26, 2020. The study included adults with suspicion of COVID-19 Infection who were transferred to the ICU. Patients were admitted to the ICU directly from the ED after reverse transcriptase-polymerase chain reaction (RT-PCR) swabs were sent to the central virology laboratory in Kuwait, and the results were released 16 to 24 hours after the time of admission. A certified intensivist in critical care ultrasound performed the lung ultrasound within 12 hours of the patient's admission to the ICU. The treating physician confirmed the diagnosis of COVID-19 pneumonia based on a set of clinical features, inflammatory markers, biochemical profile studies, RT-PCR test results, and CXR. Results Of 77 patients with suspected COVID-19 pneumonia, 65 (84.4%) were confirmed. The median age of the patients was 48 (31-68) years, and 51 (71%) were men. In the group of patients with confirmed COVID-19 pneumonia, LUS revealed four signs suggestive of COVID-19 pneumonia in 63 patients (96.9%) (sensitivity 96.9%, CI 85%-99.5%). Two patients presented with unilateral lobar pneumonia without other ultrasonic signs of COVID-19 pneumonia but with positive RT-PCR results. Among patients in the group without COVID-19 pneumonia who had negative RT-PCR results, 11 (91.7%) were LUS negative for COVID-19 pneumonia (specificity 91.7%, 95% CI 58.72%-99.77%). Conclusions During the COVID-19 outbreak, LUS allows the identification of early signs of interstitial pneumonia. LUS patterns that show a combination of the four major signs offer high sensitivity and specificity compared to nasopharyngeal RT-PCR.