Efeitos do treinamento físico associado à ventilação mecânica não invasiva na capacidade funcional de indivíduos com histórico de COVID-19 grave: estudo piloto controlado, randomizado e cego

Abstract

Introduction: In late 2019, SARS-CoV-2 triggered the COVID-19 pandemic, resulting in millions of hospitalizations and deaths. Although many have recovered, up to 20% developed long COVID (LC), characterized by persistent symptoms leading to functional limitations. Physical training improves the functional capacity of these patients, but there are still therapeutic limitations that need to be investigated. Non-invasive ventilation (NIV) with bilevel positive pressure (BIPAP) may enhance functional capacity by relieving respiratory muscle overload during training. Objective: To evaluate the association of NIV during physical training in improving the functional capacity of individuals with severe post-COVID-19. Methods: Pilot, controlled, randomized, double-blind study. Participants were individuals with severe post-COVID-19, aged 30 to 65 years, divided into two groups: physical training (GT) and physical training + NIV (GT+NIV), three times a week for eight weeks, with aerobic, resistance, and respiratory muscle training. Assessments included a 6-minute walk test (6MWT), spirometry, manovacuometry, cardiopulmonary exercise test (CPET), peripheral muscle strength (1RM), and quality of life (SF-36). Randomization was performed in blocks, with blinding of participants and evaluators. Statistical analysis used two-way ANOVA, Student's t-test, Mann-Whitney test, and Pearson correlation, with p<0.05. Results: Of the 296 participants initially recruited, 81 met the inclusion criteria. In total, 35 were randomized and 16 completed the intervention. Both groups showed improvement in the distance covered in the 6MWT (GT: p = 0.037; GT + NIV: p = 0.031), with a larger effect size in the NIV group. Quality of life improved in both groups, with emphasis on physical functionality and vitality in the GT + NIV group (p = 0.035). Respiratory muscle strength (PEmax) increased significantly in the GT + NIV group (p = 0.031), and peripheral muscle strength improved in both groups. In the CPET, peak load increased in the GT + NIV group (p = 0.036). Additional findings showed that the use of NIV reduced dyspnea and improved heart rate recovery during exercise. Conclusion: Physical training with NIV improved functional capacity and quality of life in patients with severe post-COVID-19. Regarding the acute effects on aerobic exercise on a treadmill, NIV promoted greater dyspnea relief, greater exercise tolerance, and faster heart rate recovery. Despite limitations such as low adherence and a small sample size, the results suggest that NIV can enhance rehabilitation, reinforcing the need for future studies with larger samples.