Long-term effects of difference dosage of pulmonary rehabilitation program in post severe COVID-19 patients

Maria Fernanda del Valle¹Jorge Valenzuela²Constanza Diaz-Canales²Máximo Escobar-Cabello³Fernando Valenzuela-Aedo^4,5,6Francisco Javier Soto Rodriguez^5,7Rodrigo Lizama-Pérez^8,9Gabriel Nasri Marzuca-Nassr⁵Mariano del Sol¹⁰Rodrigo Muñoz-Cofré^10,11*

• ¹Servicio de Medicina Física y Rehabilitación, Hospital El Carmen, Maipú, Chile, Santiago, Chile
• ²Servicio de Medicina Física y Rehabilitación, Hospital El Carmen, Maipú, Chile, Maipu, Chile
• ³Laboratorio de Función Disfunción ventilatoria, Departamento de Kinesiología, Universidad Católica del Maule, Talca ,Chile, Talca, Chile
• ⁴Escuela de Kinesiología, Facultad de Salud, Universidad Santo Tomás, Temuco, Chile., Temuco, Chile
• ⁵Departamento de Ciencias de la Rehabilitación, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile, Temuco, Chile
• ⁶Doctorado en Ciencias Morfológiccas, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile, Temuco, Chile
• ⁷Programa de Doctorado en Medicina Clínica y Salud Pública, Universidad de Granada, Granada, España, Granada, Spain
• ⁸Departamento de Anatomía Normal y Medicina Legal, Facultad de Medicina, Universidad de Concepción, Concepción, Chile, Concepción, Chile
• ⁹Departamento de Ciencias Morfológicas, Facultad de Medicina y Ciencia, Universidad San Sebastián, Lientur 1457, Concepción 4080871, Chile, Concepción, Chile
• ¹⁰Centro de Excelencia en Estudios Morfológicos y Quirúrgicos (CEMyQ), Facultad de Medicina, Universidadde La Frontera, Temuco, Chile, Temuco, Chile
• ¹¹Departamento de Especialidades Médicas, Facultad de Medicina, Universidad de La Frontera, Temuco, Chile., Temuco, Chile

BACKGROUND: COVID-19 can lead to severe respiratory complications requiring invasive mechanical ventilation (IMV). Post-acute sequelae often include reduced pulmonary function, decreased physical capacity, and impaired quality of life. Pulmonary rehabilitation programs (PRPs) have shown promise in aiding recovery, but the long-term effectiveness and optimal dosage (number of sessions) remain unclear. METHODS: A experimental, repeated-measures study was conducted at Hospital El Carmen de Maipú, Chile, involving 60 adults (male and female) who had received IMV due to severe COVID-19. Participants completed an individualized PRP consisting of sessions held twice weekly. Each session included 30 minutes of aerobic exercise, 20 minutes of strength training, and 10 minutes of stretching exercises. Participants were assigned to one of three intervention arms: 12, 24, or 36 sessions. Clinical outcomes included spirometric parameters, 6-minute walk distance (6-MWD), Hand Grip Strength (HGS), functional status, and dyspnea. Psychological outcomes included quality of life and fatigue. Assessments were conducted at baseline, post-intervention, and one year after the intervention. RESULTS: Twelve-session group, significant improvements in Maximum Inspiratory Pressure (MIP) and 6-MWD were observed (p < 0.05). Clinical and psychological improvements were sustained at one year. Twenty four-session group, significant changes were found in Forced Vital Capacity (FVC % predicted) and right-hand grip strength (HGS) (p < 0.05). Improvements in clinical and psychological variables persisted at one year, though additional gains were observed only in spirometric parameters between post-intervention and follow-up. Thirty six-session group, participants experienced significant improvements in physical and mental Fatigue Assessment Scale (FAS) scores, total FAS, and bodily pain (p < 0.05). These benefits remained stable at the one-year evaluation, with no significant changes between post-intervention and follow-up. CONCLUSION: Individualized PRPs produced significant improvements in clinical and psychological outcomes in patients recovering from severe COVID-19 requiring IMV. Importantly, these benefits were maintained one year after the intervention, regardless of the number of sessions (12, 24, or 36). The lack of significant long-term differences among groups suggests that a shorter but personalized rehabilitation program may be sufficient to produce durable improvements in this population. These findings support the implementation of tailored PRPs as a key component of post-COVID-19 care.