Impulse Oscillometry Findings and Their Associations With Lung Ultrasound Signs in COVID-19 Survivors.

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.

Use of a Home-Based Manual as Part of a Pulmonary Rehabilitation Program.

BACKGROUND: Pulmonary rehabilitation programs improve exercise capacity and quality of life in patients with COPD. Domiciliary strategies to maintain these benefits have been proposed. OBJECTIVE: This study aimed to determine whether a rehabilitation manual would facilitate the maintenance of the benefits acquired during out-patient pulmonary rehabilitation. METHODS: Fifty subjects with stable COPD were included (26 women and 24 men). All the subjects were evaluated during screening and after 12 wk of out-patient rehabilitation, and then were randomly divided into 2 groups, with one group that received the rehabilitation manual for home use (manual group) and the other group only received verbal recommendations (control group). At this point, the 2 groups were similar. After 12 wk at home, both groups were evaluated a third time. All evaluations included a 6-min walk test (6MWT), 6-min step test, COPD Assessment Test, and measurement of dyspnea by using the modified Medical Research Council dyspnea scale. RESULTS: When comparing the results of the 6MWT and 6-min step test done at out-patient discharge and after 12 wk at home, the manual group presented no differences (6MWT, 0 ± 25 m; 6-min step test, 1 ± 32 steps), whereas the control subjects lost part of the gain obtained during rehabilitation (6MWT -46 ± 36 m; 6-min step test -39 ± 33 steps). There was a significant difference between the groups (P < .05). When comparing the same time points, the change in the COPD Assessment Test score was -1 ± 1 for the manual group and 1 ± 2 for the control group (P = .01). For the modified Medical Research Council dyspnea scale, the change in score was 0 ± 1 for the manual group and 1 ± 1 for the control group (P = .01). CONCLUSIONS: The use of a simple, well-illustrated manual facilitated the maintenance of the benefits acquired in out-patient pulmonary rehabilitation over a period of 3 months after study termination.