The diagnostic accuracy of lung ultrasound to determine PiCCO-derived extravascular lung water in invasively ventilated patients with COVID-19 ARDS (preprint)

Background: Lung ultrasound (LUS) is a non-invasive method to detect and quantify pulmonary edema. However, it remains uncertain how components of the LUS examination should be aggregated into a score for quantifying pulmonary edema. We examined the diagnostic accuracy of various LUS scores with the extravascular lung water index (EVLWi) assessed with PiCCO in patients with moderate-to-severe COVID-19 ARDS. Methods: In this predefined secondary analysis of a multicenter randomized-controlled trial (InventCOVID), patients were included within 48h after intubation and underwent LUS and EVLWi measurement at two time points (first and fourth study day). EVLWi and ∆EVLWi were used as reference standard. Two 12-region scores (global LUS and LUS-ARDS), an 8-region anterior-lateral score and a 4-region B-line score were used as index tests. Pearson correlation was performed and the area under the receiver operating characteristics curve (AUROCC) for severe pulmonary edema (EVLWi>15mL/kg) was calculated. Results: 26 of 30 patients (87%) had complete LUS and EVLWi measurements at time point 1 and 24 of 29 patients (83%) at time point 2. The global LUS (r=0.54), LUS-ARDS (r=0.58) and anterior-lateral score (r=0.54) were significantly correlated with EVLWi, while the B-line score was not (r=0.32). ∆global LUS (r=0.49) and ∆anterior-lateral LUS (r=0.52) were significantly correlated with ∆EVLWi, while correlation of ∆LUS-ARDS (r=0.43) and ∆B-lines (r=0.32) did not reach statistical significance. AUROCC for EVLWi>15ml/kg was 0.73 for the global LUS, 0.79 for the anterior-lateral and 0.85 for the LUS-ARDS score. Conclusions: The global LUS, LUS-ARDS and antero-lateral score can quantify PiCCO-derived pulmonary edema measurements in COVID-19 ARDS. The LUS-ARDS score showed the highest diagnostic accuracy for severe pulmonary edema. Trial registration: ClinicalTrials.gov identifier NCT04794088, registered on 11 March 2021. European Clinical Trials Database number 2020-005447-23.

Lung ultrasound findings in patients with novel SARS-CoV2 (preprint)

Background: Over 2 million people worldwide have been infected with Severe Acute Respiratory Distress Syndrome Corona Virus 2 (SARS CoV2). Lung ultrasound has been proposed to diagnose and it. However, little is known about ultrasound findings in these patients. Our aim is to present an overview of lung ultrasound characteristics in critically ill patients with SARS CoV2 pneumonia overall and in relation to the duration of symptoms and clinical parameters. Methods: On the Intensive Care Unit of two academic hospitals, adult patients who tested positive for SARS-CoV2 were included. Images were analyzed for pleural line characteristics, number and appearance of B-lines, BLUE-profiles (Bedside Lung Ultrasound in Emergency), pathology in the PLAPS (Postero Lateral Alveolar and Pleural Syndrome) point and a LUS-score (lung ultrasound). The primary outcomes were frequencies, percentages and differences in lung ultrasound findings overall and between short ([≤]14 days) and long (>14 days) duration of symptoms and their correlation with clinical parameters. Results: In this pilot observational study, 61 patients were included with 75 examinations for analysis. The most prevalent ultrasound findings were decreased lung sliding (36%), thickening of the pleural line (42%) and a C-profile per view (37%). Patients with ''long'' duration of symptoms presented more frequently with a thickened and irregular pleural line (21% (32) vs 9% (11), p=.01), C-profile per patient (47% (18) vs. 25% (8),p=.01) and pleural effusion (19% (14) vs 5% (3),p=.02) compared to patients with short duration of symptoms. Lung ultrasound findings did not correlate with P/F ratio, fluid balance or dynamic compliance, with the exception of the LUS-score and dynamic compliance (R2=0.27, p=.02). Conclusion: SARS CoV2 results in significant ultrasound changes, with decreased lung sliding, thickening of the pleural line and a C-profile being the most observed. With time, a thickened and irregular pleural line, C-profile and pleural effusion become more common findings.