Study of diaphragmatic mobility by chest ultrasound and changes in maximal respiratory pressures in patients with interstitial pulmonary fibrosis before and after pulmonary rehabilitation

Abstract

Background Interstitial lung diseases (ILDs) are a diverse set of diffuse parenchymal lung illnesses defined by decreased functional capacity and exercise-induced hypoxia. Despite the inadequacy of clinical guidelines for pulmonary rehabilitation (PR) in ILD, some recent studies have indicated that rehabilitation can help patients with ILD improve their dyspnea and functional capacity. Chest ultrasound (US) is a safe and effective method to assess diaphragmatic function and the impact of PR on it. Purpose Evaluation of diaphragmatic motion and thickness by chest US, spirometry, maximal inspiratory pressure (Pi Max), maximal expiratory pressure (Pe Max), 6-minute walk test (6MWT), and modified Medical Research Council (mMRC) Dyspnea Scale in ILD patients before and after PR program from January 2019 to June 2021. Patients and methods Our study was a prospective and analytical study that included twenty patients diagnosed with ILD in Ain Shams University Hospitals (inpatients and outpatients) in the duration from January 2019 to June 2021. All patients after informed written consent were subject to chest history and examination, high-resolution computed tomography chest prerehabilitation and postrehabilitation spirometry, chest US to assess diaphragmatic excursion both at rest and with forced respiration, assessment of diaphragmatic thickness, 6MWT, and mMRC. All patients took part in a home-based PR program (mostly an exercise training program) that included two sessions per week for 8 weeks (a total of 16 sessions), which included upper-extremity and lower-extremity endurance training, as well as respiratory muscle training. Follow-up visits were scheduled every 2 weeks and included diaphragmatic US and mMRC. Results There were 14 females (70.0%) and six males (30.0%) with age ranged from 38 to 66 years with mean±SD of 49.0 ± 8.44. There was a statistically significant increase in the pulmonary functions of the studied patients after 8 weeks of rehabilitation. There was also a statistically significant increase in diaphragmatic excursion and thickness of the studied patients at 2, 4, 6, and 8 weeks after rehabilitation. There was highly significant improvement in mMRC classification at 4, 6, and 8 weeks than before rehabilitation. As for 6MWT, there was a highly statistically significant increase in the 6-min walking distance after 8 weeks of rehabilitation. Conclusion In individuals with ILD, PR improves pulmonary function, diaphragmatic thickness, and excursion, mMRC, and 6-min walking distance.

Keywords

• chest ultrasound
• diaphragm
• interstitial lung disease
• maximal expiratory pressure (pe max)
• maximal inspiratory pressure (pi max)
• pulmonary rehabilitation