Avaliação da função respiratória em pacientes com esclerose múltipla

Abstract

Introduction: Multiple Sclerosis (MS) is associated with muscle strength reduction, including respiratory muscles. Respiratory complications are the most important cause of death among patients with advanced MS. Aspiration pneumonia, atelectasis, and respiratory insufficiency are frequent in this group of patients. These complications arise as a consequence of fatigue and weakness of respiratory muscles, as well as the inability to keep airways free of secretions. MS progression can reduce physical capacity thus reducing the resistance to exercise and physical activity. Objectives: We aimed to compare respiratory parameters between MS patients and controls, as well as to correlate respiratory function with neurologic disability, fatigue, quality of life, depression, anxiety, and daytime somnolence. Patients and Methods: It was a case-control study with 30 MS patients and 30 healthy controls matched by age and gender. Maximum inspiratory pressure (PImax), maximum expiratory pressure (PEmax), and Peak Flow (PFE) were measured.Expanded scale of incapacity state (EDSS), Guy´s neurologic disability scale (GNDS), modifed fatigue impact sclale (MFIS), fatigue severity scale (FSS), health related quality of life scale (DEFU), visual ability scale (NEI-VFQ-25), Beck depression inventory (BDI), Beck anxiety inventory (BAI), Epworth somnolence scale (ESS-BR) were applied to patients and controls. A respiratory index was proposed to unify respiratory parameters (iQR) by using factorial analysis. The power of the statistic tests was evaluated with Bootstrap test. Kalmogorov-Smirnov test was usedfor normality evaluations. Mann Whitney was used to compare patients and controls continuous data. Spearman test was used for correlations. Results: The mean time of disease and mean EDSS were 8.57 years and 2,63 ± 1,65, respectively. All respiratory parameters were significantly reduced in MS patients when compared with controls (PImáx, p = 0,0092; PEmáx, p = 0,0034; PFE, p = 0,0051; iQR, p < 0,001). MS patients had significantly lower scores of BDI (p = 0,0393), BAI (p < 0,0001), MFIS (p = 0,005), and FSS (p = 0,018) than controls. Statistically significantcorrelations were found: iQR and MFIS (p = 0,037), FSS (p = 0,010), BAI (p = 0,038), and DEFU (p = 0,029); PImax and BDI (p = 0,0161). EDSS was significantly correlated with GNDS (p = 0,0174), FSS (p = 0,0271), BAI (p = 0,0312), and DEFU (p = 0,0102). BDI was significantly correlated with GNDS (p = 0,0007), MFIS (p = 0,0002), FSS (p = 0,0037), DEFU (p = 0,0002), and NEI-VFQ-25 (p = 0,0001). BAI was correlated with iQR (p = 0,038), GNDS (p < 0,0001), MFIS (p < 0,0001), FSS (p = 0,0003), DEFU (p < 0,0001), and NEI-VFQ-25 (p = 0,0002). Impact and severity offatigue were correlated with iQR (p = 0,037; p = 0,010), BDI (p = 0,0002; p = 0,0037), and BAI (p < 0,0001; p = 0,0003). Conclusion: The present study brought relevant contributions to the understanding of respiratory function in MS. We confirmed the presence of inspiratory and expiratory dysfunctions in MS, even in the early stage of the disease. We proposed a new index to facilitate the respiratory evaluation of patients with MS. Respiratory dysfunction was correlated with anxiety and depression. The present data suggest that respiratory involvement may be one of thecauses of fatigue and reduced life quality among MS patients. Respiratory evaluation should be carried out in patients with MS and future studies should clarify the role of early respiratory rehabilitation in this population.