Post-Infection Oscillometry and Pulmonary Metrics in SARS-CoV-2 Patients: A 40-Day Follow-Up Study

Abstract

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has had significant impacts on pulmonary function. This study aimed to comprehensively evaluate pulmonary function and structure in patients 40 days post-SARS-CoV-2 infection, employing an array of testing methodologies including spirometry, plethysmography, forced oscillometry, and CT scanning. It also sought to establish potential correlations between these metrics and evaluate if forced oscillometry could provide additional value in post-infective lung function assessment. A 40-day post-infection follow-up observational study was conducted involving 66 patients with confirmed SARS-CoV-2 infection. The results revealed decreases in FVC and FEF25–75 with the increasing severity of COVID-19. Specifically, patients with severe symptoms exhibited statistically significant decreases in FVC (mean = 86.8) compared with those with mild symptoms (mean = 106.0; p = 0.018). The FEF25–75 showed a similar trend, with severe patients exhibiting a mean of 77.7 compared with 82.9 in the mild group (p = 0.017). Furthermore, resonant frequency (RF) increased with disease severity, with the severe group exhibiting a statistically significant increase (mean = 17.4) compared with the mild group (mean = 14.3; p = 0.042). CT scans showed an increase in ground-glass opacities with disease severity, with 81.8% of severe patients demonstrating this finding (p = 0.037). Multiple regression analysis revealed that Reactance at 4 Hz (X4), Forced Expiratory Flow 25–75% (FEF25–75), and Resonant Frequency (RF) were significantly related to COVID-19 severity. Specifically, for each unit increase in these factors, the risk of the event was estimated to increase by a factor of 3.16, 2.09, and 1.90, respectively. Conversely, Resistance at 4 Hz (R4) and Airway Resistance (RAW) were found to significantly decrease the event hazard, highlighting their potential protective role. Spirometry, plethysmography, and forced oscillometry are effective in assessing these changes. Forced oscillometry may be particularly beneficial in identifying subtle changes in lung function post-COVID-19. Further studies are warranted to validate these findings and develop strategies to manage post-infective pulmonary changes in SARS-CoV-2 patients.

Effects of pulmonary rehabilitation on ventilation dynamics measured during exertion in patients with post-acute COVID-19 syndrome: A cross-sectional observational study

“…In line with our findings, Bonato et al [41] found that persistent dyspnea in PACS (which can be relieved by an PR program) is associated with small airway dysfunction 3 months after discharge, regardless of the parenchymal/radiological sequelae. A follow-up observational study of PACS individuals showed that, in the multiple regression analysis, reactance at 4 Hz, forced expiratory flow during the middle half of the FVC maneuver and Fres were significantly related to the severity of COVID-19 [42]. We believe that it is likely that the improvement in respiratory mechanics of these patients with PR, especially peripheral and tissue resistance (chest wall), may increase exercise tolerance with a positive impact on functional independence and QoL.…”

Impulse oscillometry in patients with persistent post‐COVID‐19 symptoms: A retrospective study

“…Certain investigations have yielded compelling evidence of significantly elevated small airway resistance in COVID‐19 positive individuals both during the acute infection phase and after a 2‐month follow‐up, 3 as well as a 40‐day follow‐up. 4 Meanwhile, alternative research has directed its focus towards chest imaging and lung ultrasound in post‐COVID‐19 patients. 5 , 6 However, other studies did not find a significant increase in small airway resistance among COVID‐19 inpatients.…”

A Three-Year Cross-Sectional Analysis of Depression, Anxiety, and Quality of Life in Patients with Post-COVID-19 Syndrome

“…decrease in respiratory challenges post-recovery across the years is promising, potentially hinting at better post-COVID respiratory care or natural improvement over time, as well as the recent development of cardiopulmonary rehabilitation techniques. [32][33][34] From an emotional perspective, the marked decrease in feelings of sadness, hopelessness, or depression affecting daily life is encouraging. This trend might reflect the resilience of the human spirit, the effectiveness of coping mechanisms, or improved support systems as the pandemic progressed, concurrently with the feeling of hope after the vaccination campaign and the pandemic reaching to an end.…”