Comparison of inspiratory muscle strength training effects between older subjects with and without chronic obstructive pulmonary disease.

BACKGROUND/PURPOSE: Inspiratory muscle strength training (IMST) has been traditionally recommended for patients with chronic obstructive pulmonary disease (COPD) to improve respiratory strength. Respiratory strength is reduced as age increases. However, few studies have focused on the effects of IMST on older adults without COPD. METHODS: Subjects were divided into training non-COPD (TNC, n = 24) and training COPD (TC, n = 12) according to their forced expiratory volume in 1 second (% predicted). Both groups received 6 weeks of IMST, with training at 75-80% of maximal inspiratory pressure using pressure threshold trainers. A second group of COPD subjects served as controls (CC, n = 24), which received no training. Dyspnea was measured using the basic dyspnea index. Health-related quality of life was measured using the SF-36. The SF-36 subcategories, physical component summary and mental component summary were compared. A 6-minute walk test was performed to determine functional status. Two-way repeated measures analysis of variance was used to compare group effects and training effects of IMST. RESULTS: Maximal inspiratory pressure was increased in both training groups (TNC: 59.1 cmH(2)O pre-IMST to 82.5 cmH(2)O post-IMST; TC: 53.2 to 72.6), but not in the CC group. Therefore, the basic dyspnea index was improved in both training groups (TNC: 9.6 to 10.8; TC: 6.2 to 7.3). Functional status was improved in the TNC group (TNC: 392.1 m to 436.3 m), but not in the TC or CC groups. Quality of life was improved in the physical component summary in both training groups. CONCLUSION: IMST increases maximal inspiratory pressure, relieves dyspnea and improves health-related quality of life in older adults. IMST especially improves functional status in subjects without COPD. IMST benefits subjects with COPD and those without COPD. Therefore, IMST as a treatment tool is not confined to patients with COPD.

Effects of physical training on functional status in patients with prolonged mechanical ventilation.

BACKGROUND AND PURPOSE: Patients requiring prolonged mechanical ventilation (PMV) are frequently deconditioned because of respiratory failure precipitated by the underlying disease, the adverse effects of medications, and a period of prolonged immobilization. The effects of 6 weeks of physical training on the strength of respiratory and limb muscles, on ventilator-free time, and on functional status in patients requiring PMV were examined. SUBJECTS: Thirty-nine patients with PMV were initially enrolled in the study and were assigned to either a treatment group (n=20) or a control group (n=19). Three subjects in the treatment group and 4 subjects in the control group died during the 6-week intervention period and thus their data were excluded from the final analysis. METHODS: Subjects in the treatment group received physical training 5 days a week for 6 weeks. Strength of respiratory and limb muscles, ventilator-free time, and functional status, which was measured by the Barthel Index of Activities of Daily Living (BI) and Functional Independence Measure (FIM), were examined at baseline and at the third and sixth weeks of the study period. RESULTS: Respiratory and limb muscle strength improved significantly at the third and sixth weeks in the treatment group compared with baseline measurements. Total BI and FIM scores increased significantly in the treatment group and remained unchanged in the control group. Effect sizes of the BI and FIM scores were 2.02 and 1.93, respectively, at the sixth week. DISCUSSION AND CONCLUSION: The results show that a 6-week physical training program may improve limb muscle strength and ventilator-free time and thus improve functional outcomes in patients requiring PMV.

Comparison of effectiveness of pressure threshold and targeted resistance devices for inspiratory muscle training in patients with chronic obstructive pulmonary disease.

BACKGROUND AND PURPOSE: Previous studies have provided little information about the comparative efficacy of treatment with pressure threshold and targeted resistive inspiratory muscle training devices. This study compared the efficacy of these two types of inspiratory muscle training (IMT) devices on inspiratory muscle function, exercise capacity, and quality of life in patients with chronic obstructive pulmonary disease (COPD). METHODS: Forty two patients with moderate to severe COPD were randomly assigned to either a control group, a group receiving pressure threshold inspiratory muscle training, or a group receiving targeted resistive inspiratory muscle training. The training intensity was 50% of patients' maximal inspiratory pressure (MIP). Home-based training comprised two 15-minute sessions a day, 5 days a week for 8 weeks. Inspiratory muscle function measurement included MIP and inspiratory muscle endurance. RESULTS: Thirty patients completed the program, 10 from each group. Twelve patients were excluded because of changes in pharmacological regimen or admission to the hospital (n = 5), study withdrawal (n = 4), or poor compliance with the training program (n = 3). After training, a significant increase in endurance time was found for the threshold group and targeted resistive group (4.4 +/- 3.2 min and 3.0 +/- 2.9 min, respectively, both p < 0.05 vs control), with no significant difference between the 2 training groups. The 6-minute walking distance also increased significantly in both training groups (p < 0.05). CONCLUSIONS: Targeted resistive IMT with a controlled training load has a similar efficacy to the more popularly used pressure threshold IMT and can be incorporated in the treatment of COPD patients. The targeted resistance device offers a less expensive and easily used treatment choice.