The effects of 1 year of specific inspiratory muscle training in patients with COPD.

AIM: We assessed the long-term benefits of inspiratory muscle training (IMT) on inspiratory muscle strength, exercise capacity, the perception of dyspnea, quality of life, primary care use, and hospitalizations in patients with significant COPD. PATIENTS: Forty-two consecutive COPD patients with FEV(1) < 50% of predicted were randomized into a group that received IMT for 1 year, and a control group that received training with a very low load. RESULTS: There was a statistically significant increase in inspiratory muscle strength (at the end of the third month of training) as assessed by maximal inspiratory pressure (from 71 +/- 4.9 to 90 +/- 5.1 cm H(2)O [+/- SEM], p < 0.005) and 6-min walk distance (at the end of the third month of training; from 256 +/- 41 to 312 +/- 54 m; p < 0.005), a decrease in the mean Borg score during breathing against resistance (at the end of the ninth month of training), improvement in the health-related quality-of-life scores (at the end of the sixth month of training) in the training group but not in the control group. At the end of the training year, these changes were maintained; in addition, a decrease in primary health-care use and hospitalization days was observed. CONCLUSIONS: Our study shows that during IMT in patients with significant COPD, there is an increase in exercise capacity, improvement in quality of life, and decrease in dyspnea. Our study also provides evidence that long-term IMT can decrease the use of health services and hospitalization days.

Comparison of specific expiratory, inspiratory, and combined muscle training programs in COPD.

BACKGROUND: Respiratory muscle weakness may contribute to dyspnea and exercise limitation in patients with significant COPD. In an attempt to reduce the severity of breathlessness and to improve exercise tolerance, inspiratory muscle training has been applied in many COPD patients. On the other hand, there is a paucity of data related to expiratory muscle performance and training in COPD. METHODS: Thirty-two patients with significant COPD (ie, mean FEV(1), 37% of predicted) were recruited for the study. The patients were randomized into four groups: eight patients were assigned to receive specific expiratory muscle training (SEMT); eight patients received specific inspiratory muscle training (SIMT); eight patients received SEMT and SIMT (ie, the SEMT + SIMT group); and eight patients who were assigned to a control group received training with very low load. All patients trained daily, six times a week, with each session consisting of one half hour of training, for 3 months. Spirometry, respiratory muscle strength and endurance, 6-min walk test distance, the perception of dyspnea, and the Mahler baseline dyspnea index (BDI) were measured before and following training. RESULTS: Training caused a statistically significant specific increase in the expiratory muscle strength and endurance (in the SEMT and SEMT + SIMT groups) and in the inspiratory muscle strength and endurance (in the SIMT and SEMT + SIMT groups). There was significant increase in the distance walked in 6 min in the SEMT, SIMT, and SEMT + SIMT groups. However, the increase in the SIMT and SEMT + SIMT groups was significantly greater than that in the SEMT group. There was a statistically significant increase in the BDI, and a decrease in the mean Borg score during breathing against resistance in the SIMT and SEMT + SIMT groups, with no changes in the SEMT and control groups. CONCLUSIONS: The inspiratory and expiratory muscles can be specifically trained with improvement of both muscle strength and endurance. The improvement in the inspiratory muscle performance is associated with an increase in the 6-min walk test distance and the sensation of dyspnea. There is no additional benefit gained by combining SIMT with SEMT, compared to using SIMT alone.

Specific expiratory muscle training in COPD.

BACKGROUND: There are several reports showing that expiratory muscle strength and endurance can be impaired in patients with COPD. This muscle weakness may have clinically relevant implications. Expiratory muscle training tended to improve cough and to reduce the sensation of respiratory effort during exercise in patients other than those with COPD. METHODS: Twenty-six patients with COPD (FEV(1) 38% predicted) were recruited for the study. The patients were randomized into two groups: group 1, 13 patients were assigned to receive specific expiratory muscle training (SEMT) daily, six times a week, each session consisting of 1/2 h of training, for 3 months; and group 2, 13 patients were assigned to be a control group and received training with very low load. Spirometry, respiratory muscle strength and endurance, 6-min walk test, Mahler baseline dyspnea index (before), and the transitional dyspnea index (after) were measured before and after training. RESULTS: The training-induced changes were significantly greater in the SEMT group than in the control group for the following variables: expiratory muscle strength (from 86 +/- 4.1 to 104 +/- 4.9 cm H(2)O, p < 0.005; mean difference from the control group, 24%; 95% confidence interval, 18 to 32%), expiratory muscle endurance (from 57 +/- 2.9% to 76 +/- 4.0%, p < 0.001; mean difference from the control group, 29%; 95% confidence interval, 21 to 39%), and in the distance walked in 6 min (from 262 +/- 38 to 312 +/- 47 m, p < 0.05; mean difference from the control group, 14%; 95% confidence interval, 9 to 20%). There was also a small but not significant increase (from 5.1 +/- 0.9 to 5.6 +/- 0.7, p = 0.14) in the dyspnea index. CONCLUSIONS: The expiratory muscles can be specifically trained with improvement of both strength and endurance in patients with COPD. This improvement is associated with increase in exercise performance and no significant change in the sensation of dyspnea in daily activities.

Inspiratory muscle training may increase peak inspiratory flow in chronic obstructive pulmonary disease.

BACKGROUND: When choosing a specific inhalation device for a chronic obstructive pulmonary disease (COPD) patient, the internal airflow resistance and the ability of the patient to overcome it and to create an optimal inspiratory flow are essential. OBJECTIVES: The purpose of the present study was to investigate: (1) the peak inspiratory flow (PIF) that a patient with COPD can generate while breathing through two dry powder inhalers and (2) whether in patients with low PIF specific inspiratory muscle training (SIMT) will increase the PIF and exceed the minimal PIF that is considered necessary to guarantee optimal lung deposition of the drug. METHODS: Inspiratory muscle strength and PIFs were measured in 60 patients with COPD. Then 28 patients with severe COPD and low PIF were randomized to receive SIMT or to a control group. RESULTS: With the Turbuhaler, 12 patients (20%) could not generate the optimal flow of 60 l/min. PIF correlated very well with maximal inspiratory mouth pressure (PI(max)) for the Diskus and the Turbuhaler, as well as for both males and females (p < 0.001). Following the training period, there was a statistically significant increase in the PI(max) in the training group. This increase was associated with a significant increase in the PIF. All patients overcame the minimal threshold PIF following the training. CONCLUSIONS: Some patients with severe COPD are not able to generate adequate flow to secure optimal lung deposition of the inhalation with the Turbuhaler. SIMT improves inspiratory muscle strength as well as PIF. Following 8 weeks of training, the optimal PIF enabling adequate lung deposition of the drug was attained in all the trained patients.