Lung ultrasound for the early diagnosis of COVID-19 pneumonia: an international multicenter study.

PURPOSE: To analyze the application of a lung ultrasound (LUS)-based diagnostic approach to patients suspected of COVID-19, combining the LUS likelihood of COVID-19 pneumonia with patient's symptoms and clinical history. METHODS: This is an international multicenter observational study in 20 US and European hospitals. Patients suspected of COVID-19 were tested with reverse transcription-polymerase chain reaction (RT-PCR) swab test and had an LUS examination. We identified three clinical phenotypes based on pre-existing chronic diseases (mixed phenotype), and on the presence (severe phenotype) or absence (mild phenotype) of signs and/or symptoms of respiratory failure at presentation. We defined the LUS likelihood of COVID-19 pneumonia according to four different patterns: high (HighLUS), intermediate (IntLUS), alternative (AltLUS), and low (LowLUS) probability. The combination of patterns and phenotypes with RT-PCR results was described and analyzed. RESULTS: We studied 1462 patients, classified in mild (n = 400), severe (n = 727), and mixed (n = 335) phenotypes. HighLUS and IntLUS showed an overall sensitivity of 90.2% (95% CI 88.23-91.97%) in identifying patients with positive RT-PCR, with higher values in the mixed (94.7%) and severe phenotype (97.1%), and even higher in those patients with objective respiratory failure (99.3%). The HighLUS showed a specificity of 88.8% (CI 85.55-91.65%) that was higher in the mild phenotype (94.4%; CI 90.0-97.0%). At multivariate analysis, the HighLUS was a strong independent predictor of RT-PCR positivity (odds ratio 4.2, confidence interval 2.6-6.7, p < 0.0001). CONCLUSION: Combining LUS patterns of probability with clinical phenotypes at presentation can rapidly identify those patients with or without COVID-19 pneumonia at bedside. This approach could support and expedite patients' management during a pandemic surge.

Lung Ultrasound to Predict COVID-19 Pneumonia: A Multicenter Descriptive Study (preprint)

Background: The pandemic surge of Coronavirus disease 2019 (COVID-19) is posing the unprecedent challenge of rapidly identifying and isolating probable cases and diagnosing the main respiratory complications. We aimed to describe the application of a lung ultrasound (LUS)-based diagnostic approach, combining the LUS likelihood of COVID-19 pneumonia with patient’s symptoms and clinical history.Methods: This is an international multicenter prospective observational study on patients suspected for COVID-19, presenting to 22 different US and European hospitals. Patients underwent LUS and reverse transcription-polymerase chain reaction (RT-PCR) swab test. We identified 3 different clinical phenotypes based on pre-existing chronic cardiac or respiratory diseases (mixed phenotype), and on the presence (severe phenotype) or absence (mild phenotype) of signs and/or symptoms of respiratory failure at presentation. We defined the LUS likelihood of COVID-19 pneumonia according to 4 different patterns, characterized by the presence and distribution of typical and atypical LUS signs: high (HPLUS), intermediate (IPLUS), alternative (APLUS) and low (LPLUS) probability patterns. The association between the combination of patterns and phenotypes with RT-PCR results was described and analyzed.Findings: We studied 1462 patients, classified in mild (n=400), severe (n=727) and mixed (n=335) phenotypes. In the overall population, the HPLUS corresponded to a positive RT-PCR in 92.6% of cases, with similarly high percentages in all clinical phenotypes ranging from 87.5% (mild) to 90.3% (mixed) and 96.5% (severe). The IPLUS yielded a lower match with positive RT-PCR (65.7%). In patients with respiratory failure, the LPLUS predicted a negative RT-PCR in 100% of cases. In the overall population, the APLUS indicated an alternative pulmonary condition in 81.1% of patients. At multivariate analysis the HPLUS strongly predicted RT-PCR positivity (odds ratio 4.173, interquartile range 2.595-6.712, p<0.0001), independently from age, low oxygen saturation and dyspnea.Interpretation: Combining LUS patterns of probability for interstitial pneumonia with clinical phenotypes at presentation could facilitate the early diagnosis of COVID-19 or suggest an alternative pulmonary condition. This approach may be useful to rapidly guide and support patient’s allocation for a wiser use of hospital resources during a pandemic surge.Funding: None.Conflict of Interest: The authors declare no conflicts of interest. Ethical Approval: The local Ethical Committee Boards of each center approved the study, and the study was conducted following the ethical standards of the 1964 Helsinki declaration and its later amendments and with local guidelines for good clinical practice.

Systematic testing for venous thromboembolism in hospitalized patients with COVID-19 and raised D-dimer levels

Background Hospitalized patients with COVID-19 and raised D-dimer levels have high rates of venous thromboembolism (VTE). Methods We used data from hospitalized patients with COVID-19 that were tested for pulmonary embolism (PE) or deep vein thrombosis (DVT) because of raised D-dimer levels. We aimed to identify patients at increased risk for VTE. Results From March 25 to July 5th 2020, 1,306 hospitalized patients with COVID-19 and raised D-dimer levels underwent testing for VTE in 12 centers. In all, 171 of 714 (24%) had PE, and 161 of 810 (20%) had DVT. The median time elapsed from admission to VTE testing was 12 days, and the median time from D-dimer measurement to testing 2 days. Most patients with VTE were men (62%), mean age was 62±15 years, 45% were in an intensive care unit. Overall, 681 patients (52%) received VTE prophylaxis with standard doses, 241 (18%) with intermediate doses and 100 (7.7%) with therapeutic doses of anticoagulants. On multivariable analysis, patients with D-dimer levels >20 times the upper normal range (19% of the whole cohort) were at increased risk for VTE (odds ratio [OR]: 3.24;95%CI: 2.18-4.83), as were those with a platelet count <100,000/μL (OR: 4.17;95%CI: 1.72-10.0). Conclusions Hospitalized patients with COVID-19 and D-dimer levels >20 times the upper normal range were at an increased risk for VTE. This may help to identify what patients could likely benefit from the use of higher than recommended doses of anticoagulants for VTE prophylaxis.