ABSTRACT
The pulmonary limitations after COVID-19 are still not completely known. Lung function test (LFT) and 6-minute walk test (6MWT) are accessible and safe tests to access them. Aim(s): To evaluate the differences between non-severe and severe COVID-19 patients regarding LFT and 6MWT. Method(s): This study included patients with previous COVID-19 assessed in Pulmonology Department at 2 hospitals during 7 months who performed LFT and 6MWT. Baseline and immediately pos-6MWT heart rate (HR), SpO2, respiratory rate (RR) and perceived symptoms using a modified BORG scale were collected. We compared nonsevere and severe patients. Result(s): We included 151 patients, 69 (45.7%) with severe disease. LFT was performed 116.8+/-68.3days and the 6MWT 129.1+/-72.3days after COVID-19, without statistical difference between groups. We documented lower %FVC (94.4+/-14.7vs101.1+/-12.6%, p=0.003), %TLC (95.4+/-15.3vs107.1+/-12.3%, p=0.000) and %DLCO (68.8+/-16.5vs78.9+/-15.9%, p=0.000) in the severe group, without statistical differences in FEV1, FEV1/FVC and KCO. The 6MWT distance (m: 426.5+/-110.9vs498.2+/-93.5m, p=0.000;%:77.3+/-16.8%vs86.1+/-13.4%, p=0.001), estimated metabolic equivalents (3.03+/-0.5vs3.4+/-0.4, p=0.000) and minimal SpO2 (92.0+/-3.3vs93.8+/-3.1%, p=0.000) were lower in the severe group. The time spent below 90%SpO2 (5.6+/-19.4vs2.6+/-13.6%, p=0.039), %age-predicted maximal HR (68.5+/-10.5vs64.9+/-8.8%, p=0.023) and initial RR (19.1+/-5.1vs18.7+/-9.3 cpm, p=0.014) were higher. We did not document differences regarding the differential (maximal-initial) HR, final RR, differential (final-initial) RR and symptoms. Conclusion(s): Severe group showed higher functional limitation, mainly in lung volumes and in submaximal exercise evaluation.