This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
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 H2O/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 = .002). Abnormal spirometry had a significant but weaker association with abnormal LUS (P = .031). In participants who reported hospitalization, abnormal IOS was associated with both abnormal LUS (P = .001) and abnormal spirometry (P = .006). In participants who did not report hospitalization, abnormal IOS was associated with abnormal LUS (P < .001) but not abnormal spirometry (P = .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.
Footnotes
- Correspondence: Agnaldo J Lopes PhD, Rua Araguaia, 1266, bloco 1/405, Freguesia, Jacarepaguá, 22745–271, Rio de Janeiro, Rio de Janeiro, Brazil. E-mail: agnaldolopes.uerj{at}gmail.com
This study was supported by the Conselho Nacional de Desenvolvimento Científico e Tecnólogico (CNPq; grant number #302215/2019-0), Brazil, and Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ; grant numbers #E-26/202.679/2018 and #E-26/010.002124/2019), Brazil. Dr Lopes received all these grants from CNPq and FAPERJ.
The authors have no conflicts to disclose.
- Copyright © 2021 by Daedalus Enterprises
Pay Per Article - You may access this article (from the computer you are currently using) for 1 day for US$30.00
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.