Background Thousands of people worldwide are suffering the consequences of coronavirus disease-2019 (COVID-19), and impulse oscillometry (IOS) and lung ultrasound (LUS) might be important tools for the follow-up of this population. Our objective was to prospectively evaluate abnormalities detected using these two methods in a cohort of COVID-19 survivors with respiratory symptoms. Methods In this follow-up study, 59 patients underwent clinical evaluations, spirometry, IOS and LUS in the 2nd (M1) and 5th (M2) months after diagnostic confirmation of COVID-19 by real-time reverse transcriptase–polymerase chain reaction. Aeration scores were obtained from the LUS exams based on the following findings: B-lines >2, coalescent B-lines, and subpleural consolidations. Results Fifty-nine (100%) participants had cough and/or dyspnea at M1, which decreased to 38 (64.4%) at M2 (p = 0.0001). Spirometry was abnormal in 26 (44.1%) and 20 (33.9%) participants at M1 and M2, respectively, although without statistical significance (p = 0.10). Normal examination, restrictive patterns, and obstructive patterns were observed in 33 (55.9%), 18 (30.5%), and 8 (13.6%) participants, respectively, at M1 and in 39 (66.1%), 13 (22%), and 7 (11.9%) participants at M2 (p = 0.14). Regarding IOS, considering changes in resistive and reactive parameters, abnormal exams were detected in 52 (88.1%) and 42 (71.2%) participants at M1 and M2, respectively (p = 0.002). Heterogeneity of resistance between 4 and 20 Hz >20% was observed in 38 (64.4%) and 33 (55.9%) participants at M1 and M2, respectively (p = 0.30). Abnormal LUS was observed in 46 (78%) and 36 (61%) participants at M1 and M2, respectively (p = 0.002), with a reduction in aeration scores between M1 and M2 [5 (2–8) vs. 3 (0–6) points, p<0.0001]. Conclusions IOS and LUS abnormalities are frequent in the first 5 months post-COVID-19 infection; however, when prospectively evaluated, significant improvement is evident in the parameters measured by these two methods.

BACKGROUND: Because impulse oscillometry (IOS) can detect changes in the small airways and is safer to perform during the COVID-19 pandemic than other pulmonary function tests, it may have value in investigating pulmonary sequelae in COVID-19 survivors. This study evaluated the performance of IOS in detecting lung abnormalities in COVID-19 survivors and investigated the associations of the findings with those of lung ultrasound (LUS) and spirometry. METHODS: In this cross-sectional study, 117 subjects underwent IOS at a frequency range of 4-20 Hz 2 months after COVID-19 diagnosis. They also underwent spirometry and LUS, and their aeration scores were calculated. RESULTS: On IOS, the resonance frequency was > 12 Hz, and the area under the reactance curve was > 3.60 cm H 2 O/L/s in 70 (59.8%) and 55 (47.0%) subjects, respectively. A heterogeneity of resistance between R4 and R20 (R4-R20) > 20% was observed in 60 (51.3%) participants. Based on their abnormalities in resistive and reactive parameters, 76 (65.0%) participants had abnormal IOS. Spirometry abnormalities were detected in 40 (34.2%) cases. LUS was abnormal in 51 (43.6%) participants, and the median aeration score was 0 (0-8) points. Abnormal IOS was associated with abnormal LUS (P < .001) and abnormal spirometry (P 5 .002). Abnormal spirometry had a significant but weaker association with abnormal LUS (P 5 .031). In participants who reported hospitalization, abnormal IOS was associated with both abnormal LUS (P 5 .001) and abnormal spirometry (P 5 .006). In participants who did not report hospitalization, abnormal IOS was associated with abnormal LUS (P < .001) but not abnormal spirometry (P 5 .063). CONCLUSIONS: In COVID-19 survivors, IOS detected changes even when spirometry was normal. In these individuals, IOS parameters were more strongly associated with abnormalities on LUS than with abnormalities on spirometry.

Background The role of lung ultrasound (LUS) in evaluating the mid- and long-term prognoses of patients with COVID-19 pneumonia is not yet known. The objectives of this study were to evaluate associations between LUS signs at the time of screening and clinical outcomes 1 month after LUS and to assess LUS signs at the time of presentation with known risk factors for COVID-19 pneumonia. Methods This was a retrospective study of data prospectively collected 1 month after LUS screening of 447 adult patients diagnosed with COVID-19 pneumonia. Sonographic examination was performed in screening tents with the participants seated. The LUS signs (B-lines > 2, coalescent B-lines, and subpleural consolidations) were captured in six areas of each hemithorax and a LUS aeration score was calculated; in addition, the categories of disease probability based on patterns of LUS findings (high-probability, intermediate-probability, alternate, and low-probability patterns) were evaluated. The LUS signs at patients’ initial evaluation were related to the following outcomes: symptomatology, the need for hospitalization or invasive mechanical ventilation (IMV), and COVID-19-related death. Results According to the evaluations performed 1 month after LUS screening, 36 patients were hospitalised, eight of whom required intensive care unit (ICU) admission and three of whom died. The presence of coalescent B-lines was associated with the need for hospitalization (p = 0.008). The presence of subpleural consolidations was associated with dyspnoea (p < 0.0001), cough (p = 0.003), the need for hospitalization (p < 0.0001), the need for ICU admission (p < 0.0001), and death (p = 0.002). A higher aeration score was associated with dyspnoea (p < 0.0001), the need for hospitalization (p < 0.0001), the need for ICU admission (p < 0.0001), and death (p = 0.003). In addition, patients with a high-probability LUS pattern had a higher aeration score (p < 0.0001) and more dyspnoea (p = 0.024) and more often required hospitalization (p < 0.0001) and ICU admission (p = 0.031). Conclusions In patients with COVID-19 pneumonia, LUS signs were related to respiratory symptoms 1 month after LUS screening. Strong relationships were identified between LUS signs and the need for hospitalization and death.

Purpose: To evaluate ultrasound signs of coronavirus disease-19 (COVID-19) pneumonia in symptomatic healthcare professionals and to correlate those changes with clinical findings. Methods: All patients underwent real-time polymerase chain reaction (RT-PCR), lung ultrasound (LUS) and clinical evaluation on the same day. In each of the 12 areas evaluated in the LUS, the LUS signs were scored to generate the aeration score. Results: A total of 409 participants had positive PCR, with a median age of 41 (35-51) years. All participants had clinical symptoms, with cough in 84.1%, fever in 69.7%, and dyspnea in 36.2% of cases. In the LUS, 72.6% of participants had B-lines >2, 36.2% had coalescent B-lines, and 8.06% had subpleural consolidations. The median aeration score was 3 (2-7). The aeration score differed significantly regarding the presence of cough (P = .002), fever (P = .001), and dyspnea (P < .0001). The finding of subpleural consolidations in the LUS showed significant differences between participants with or without dyspnea (P < .0001). Conclusions: In healthcare professionals with COVID-19, LUS plays a key role in the characterization of lung involvement. Although B-lines are the most common ultrasound sign, subpleural consolidations are those that most impact the respiratory condition.

Postacute COVID-19 has become a relevant public health problem, and radiological and pulmonary function tests are tools that help physicians in decision-making. The objectives of this study are to characterize the findings and patterns on a chest radiograph (CXR) and computed tomography (CT) that are most important in the postacute phase and to evaluate how these changes correlate with clinical data, spirometry, and impulse oscillometry (IOS). This was a retrospective study of 29 patients who underwent CXR, CT, spirometry, and IOS. The inclusion criteria were age >18 years and persistent respiratory symptoms after four weeks. The exclusion criteria were radiological exams with low technical quality and non-COVID-19 acute lung diseases. The inferential analysis was carried out with the chi-square (χ2) or Fisher’s exact test to evaluate the interrelationships between the clinical and COVID-19 variables according to spirometry, IOS, CT, and CXR. In our sample, 19 patients were women (65.5%). The predominance of abnormal spirometry was associated with CT’s moderate/severe degree of involvement ( p  = 0.017; 69.2%, CI 95%: 44.1%–94.3%). There was no significant association between IOS and tomographic and radiographic parameters. A significant association was found between the classifications of the moderate/severe and normal/mild patterns on CT and CXRs ( p  = 0.003; 93.3%, CI 95%: 77.8%–100%). Patients with moderate/severe impairment on CXR were associated with a higher frequency of hospitalization ( p  = 0.033; 77.8%, CI 95%: 58.6%–97.0%) and had significantly more moderate/severe classifications in the acute phase than the subgroup with normal/mild impairment on CXR ( p  = 0.017; 88.9%, CI 95%: 74.4%–100%). In conclusion, the results of this study show that CXR is a relevant examination and may be used to detect nonspecific alterations during the follow-up of post-COVID-19 patients. Small airway disease is an important finding in postacute COVID-19 syndrome, and we postulate a connection between this pattern and the persistently low-level inflammatory state of the lung.