Inspiratory muscular training in chronic stroke survivors: a randomized controlled trial. Respiratory muscle training improves cardiopulmonary function and exercise tolerance in subjects with subacute stroke: a randomized controlled trial. Prophylactic inspiratory muscle training in patients undergoing coronary artery bypass graft. The effects of inspiratory muscle training in patients with cystic fibrosis. Resistive inspiratory muscle training and exercise performance in COPD patients. A comparative study with conventional breathing retraining. Inspiratory muscle training in patients with cystic fibrosis. Inspiratory muscle training is ineffective in mechanically ventilated critically ill patients. Effects of an inspiratory muscle rehabilitation program in the postoperative period of cardiac surgery. Effects of conventional physical therapy and functional strength training on upper limb motor recovery after stroke: a randomized phase II study.
To assess the effectiveness of inspiratory muscular training (IMT) on measures of strength, resistance, functional performance, and quality of life (QOL) for chronic stroke survivors.
                Double-blinded randomized controlled trial.
                Research laboratory.
                Subjects (N=21) with stroke (11 men, 10 women; maximal inspiratory pressure [MIP] <90% of predicted values) were randomly assigned to the experimental (n=11) and control groups (n=10); 18 participants completed all testing and training.
                Interventions were based on home-based training, with resistance adjusted biweekly to 30% of MIP for the experimental group. The control group underwent the same protocol without the threshold resistance valve. Both groups received home training 30 minutes a day 5 times a week for 8 weeks.
                MIP, inspiratory muscular endurance (IME), functional performance, and QOL.
                There were significant between-group differences for the MIP and IME measures. Significant changes were observed for only the experimental group for MIP (67.8±14.6 at baseline to 102.2±26.0cmH(2)O at posttraining) and IME (31.8±19.3 to 49.2±21.1cmH(2)O). No statistically significant differences were observed for measures of functional performance and QOL.
                Significant short-term effects of the IMT program for inspiratory strength and endurance were observed in chronic stroke survivors. These findings gave some indications that IMT may benefit people with stroke, and it is feasible to be included in rehabilitation interventions with this population.
                Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved. To determine whether two types of exercise--breathing retraining (BRT) and inspiratory muscle training (IMT)--improve on cardiopulmonary functions and exercise tolerance in patients with stroke.
                A randomized controlled trial.
                Education and research hospital.
                Forty-five inpatients with stroke (24 men, 21 women) were recruited for the study. The subjects were randomized into three groups: 15 assigned to receive inspiratory muscle training (IMT); 15 assigned to received breathing retraining, diaphragmatic breathing and pursed-lips breathing (BRT); 15 assigned to a control group.
                All study groups participated in a conventional stroke rehabilitation programme. For the same period, the IMT and BRT groups trained daily, six times a week, with each session consisting of one half-hour of training for six weeks.
                Each subject underwent pulmonary function and cardiopulmonary exercise tests. Subjects were also assessed for exertional dyspnoea, stages of motor recovery, ambulation status, activity of daily living and quality of life.
                After the training programme, the IMT group had significantly improved forced expiratory volume at 1 second (FEV(1)), forced vital capacity (FVC), vital capacity (VC), forced expiratory flow rate 25-75% (FEF 25-75%) and maximum voluntary ventilation (MVV) values compared with the BRT and control groups, although there were no significant differences between the BRT and control groups (P<0.01). Peak expiratory flow rate (PEF) value was increased significantly in the BTR group compared with the IMT and control groups. The IMT group also had significantly higher peak oxygen consumption (Vo(2peak)) than the BRT and control groups, although there were no significant differences between the BRT and control groups (P<0.001). There was a statistically significant increase in maximum inspiratory pressure (PI(max)) and maximum inspiratory and expiratory pressure (PE(max)) in the BRT group and, PI(max) in the IMT group compared with baseline and the control group. In the IMT group, this was associated with improvements in exercise capacity, sensation of dyspnoea and quality of life.
                Significant short-term effects of the respiratory muscle training programme on respiratory muscle function, exercise capacity and quality of life were recorded in this study. Pulmonary complications after cardiac surgery are a leading cause of postoperative morbidity and mortality. Respiratory muscle weakness may contribute to the postoperative pulmonary abnormalities. We hypothesized that: (1) there is a decrease in inspiratory muscle strength (PImax at residual volume) and endurance (Pmpeak/PImax) following coronary artery bypass graft (CABG); (2) this weakness is associated with reduced pulmonary function tests (PFTs), impaired gas exchange, and a higher rate of pulmonary complications; and (3) prophylactic inspiratory muscle training (IMT) can prevent those changes. Eighty-four candidates for CABG, with ages ranging from 33 to 82 years, were evaluated prior to operation and randomized into two groups: 42 patients underwent IMT using a threshold trainer for 30 min/day for 2 weeks, 1 month before operation (group A); 42 patients served as a control group and underwent sham training (group B). There was a significant decrease in respiratory muscle function, PFTs, and gas exchange in the control group following CABG, whereas these parameters remained similar to those before entering the study in the training group. The differences between the groups were statistically significant. In addition 11 (26%) patients in the control group but only 2 (5%) in the training group needed postsurgical mechanical ventilation longer than 24 hours, CABGs have a significant deteriorating effect on inspiratory muscle function, PFTs, and arterial blood gases. The decrease in these parameters can be prevented by prophylactic inspiratory muscle training, which may also prevent postsurgical pulmonary complications. This study evaluated whether inspiratory muscle training (IMT) could increase inspiratory muscle strength and endurance and exercise performance in 11 patients with cystic fibrosis (CF) with moderately severe airflow limitation. The IMT consisted of breathing through an inspiratory resistance (IR) for 15 min twice daily for 4 wk, preceded or followed by a 4-wk control period. After IMT, there was an increase in inspiratory muscle strength measured by maximal inspiratory mouth pressure at functional residual capacity: 74 +/- 18 cmH2O before training to 81 +/- 12 cmH2O after training, mean +/- 1 SD, p less than 0.025, and in inspiratory muscle endurance measured by the maximal IR tolerated for 10 min. Limitation of performance in the progressive exercise test was related to increased airflow limitation and possibly to poor nutrition. Mean exercise performance during progressive or submaximal exercise testing did not change after training. It is concluded that this form of IMT improved inspiratory muscle strength and endurance, but had little effect on exercise performance in patients with CF. Twenty patients with stable COPD (mean age 67.8 yr; mean FEV1 1.08 1), all limited by ventilation at maximum exercise, were randomly allocated after a four week control period, to an eight week programme of either inspiratory resistive training (IRT), with a P Flex device, or conventional breathing retraining (BR). Exercise performance was evaluated every four weeks, using a 12-min walking test, an incremental progressive exercise on a cycle ergometer and a cycle endurance test. Inspiratory muscle endurance was measured as the highest tolerated resistance for 10 min on a P Flex device. IRT produced a significant (p less than 0.05) increase in the highest tolerated resistance, but IRT and BR failed to improve lung function or exercise performance. The present study shows that in COPD patients with ventilatory limitation on exercise an IRT programme may fail to improve exercise performance, in spite of an efficient training effect on the endurance of the inspiratory muscles. Little information is available about the effects of inspiratory muscle training in patients with cystic fibrosis (CF). In this study the effects of inspiratory-threshold loading in patients with CF on strength and endurance of the inspiratory muscles, pulmonary function, exercise capacity, dyspnoea and fatigue were evaluated. Sixteen patients were assigned to one of two groups using the minimization method: eight patients in the training group and eight patients in the control group. The training was performed using an inspiratory-threshold loading device. Patients were instructed to use the threshold trainer 20 min a day, 5 days a week for 6 weeks. Patients in the training group trained at inspiratory threshold loads up to 40% of maximal static inspiratory pressure (Pimax) and patients in the control group got 'sham' training at a load of 10% of Pimax. No significant differences were found among the two groups in gender, age, weight, height, pulmonary function, exercise capacity, inspiratory-muscle strength and inspiratory-muscle endurance before starting the training programme. Mean (SD) age in the control group was 19 (5.5) years, mean (SD) age in the training group was 17 (5.2) years. Mean FEV1 in both groups was 70% predicted, mean inspiratory-muscle strength in both groups was above 100% predicted. All patients except one, assigned to the training group, completed the programme. After 6 weeks of training, mean inspiratory-muscle endurance (% Pimax) in the control group increased from 50% to 54% (P = 0.197); in the training group mean inspiratory muscle endurance (% Pimax) increased from 49% to 66% (P = 0.003). Statistical analysis showed that the change in inspiratory-muscle endurance (% Pimax) in the training group was significantly higher than in the control group (P = 0.012). After training, in the training group there was a tendency of improvement in Pimax with an increase from 105 to 123% predicted, which just fell short of statistical significance (P = 0.064). After training no significant differences were found in changes from baseline in pulmonary function, exercise capacity, dyspnoea and fatigue. It is concluded that low-intensity inspiratory-threshold loading at 40% of Pimax was sufficient to elicit an increased inspiratory-muscle endurance in patients with CF. Invasive mechanical ventilation is associated with complications, and its abbreviation is desirable. The imbalance between increased workload, decreased inspiratory muscle strength and endurance is an important determinant of ventilator dependence. Low endurance may be present due to respiratory muscle atrophy, critical illness, or steroid use. Specific inspiratory muscle training may increase or preserve endurance. The objective of the study was to test the hypothesis that inspiratory muscle training from the beginning of mechanical ventilation would abbreviate the weaning duration and decrease reintubation rate. As a secondary objective, we described the evolution of inspiratory muscle strength with and without inspiratory muscle training.
                Prospective, randomized clinical trial in an adult clinical-surgical intensive care unit. Twelve patients trained the inspiratory muscles twice a day, and 13 patients did not (control). Training was performed adjusting the sensitivity of the ventilator based on the maximal inspiratory pressure. Patients underwent daily surveillance of the maximal inspiratory pressure.
                The weaning duration (31 +/- 22 hr, control and 23 +/- 11 hr, training group; P = .24) and reintubation rate (5 control and 3 training group; P = .39) were not statistically different. The maximal inspiratory pressure of the control group showed a trend toward a modest increase. In contrast, the training group showed a small decrease (P = .34).
                In acute critically ill patients, inspiratory muscle training from the beginning of mechanical ventilation neither abbreviated the weaning duration, nor decreased the reintubation rate. Inspiratory muscle strength tended to stay constant, along the mechanical ventilation, with or without this specific inspiratory muscle training. Respiratory muscles are affected after cardiac surgeries.
                To verify whether the preoperative conditioning of the inspiratory muscles might help to decrease postoperative respiratory dysfunction.
                Thirty volunteers of both genders and with a minimum age of 50 years, while waiting for myocardial revascularization and/or cardiac valve surgery, were randomly assigned to two groups. Fifteen patients were included in a domiciliary program of at least 2 weeks of preoperative training of the inspiratory muscles, using a device with a load corresponding to 40% of the maximum inspiratory pressure. The other 15 patients received general advice and did not train the inspiratory muscle. Spirometry, before and after the training program, as well as the evolution of the arterial blood gases and of the maximum inspiratory and expiratory pressure, before and after the operation were evaluated in both group. The clinical outcomes of the two groups were also compared.
                We observed that inspiratory muscle training increased the forced vital capacity, the maximum voluntary ventilation and the ratio between the forced expired volume during the first second and the forced vital capacity. The evolution of the arterial blood gases and of the maximum inspiratory and expiratory pressures before and after the operation was similar in both groups, with the outcomes also being similar.
                We concluded that our domiciliary program of inspiratory muscle training was safe and improved the forced vital capacity and the maximum voluntary ventilation, although the clinical benefits of this program were not clearly demonstrable in the present study. Functional training and muscle strength training may improve upper limb motor recovery after stroke. Combining these as functional strength training (FST) might enhance the benefit, but it is unclear whether this is better than conventional physical therapy (CPT). Comparing FST with CPT is not straightforward.
                This study aimed at assessing the feasibility of conducting a phase III trial comparing CPT with FST for upper limb recovery.
                Randomized, observer-blind, phase II trial. Subjects had upper limb weakness within 3 months of anterior circulation infarction. Subjects were randomized to CPT (no extra therapy), CPT + CPT, and CPT + FST. Intervention lasted 6 weeks. Primary outcome measure was the Action Research Arm Test (ARAT). Measurements were taken before treatment began, after 6 weeks of intervention, and 12 weeks thereafter. Attrition rate was calculated and differences between groups were interpreted using descriptive statistics. ARAT data were used to inform a power calculation.
                Thirty subjects were recruited (8% of people screened). Attrition rate was 6.7% at outcome and 40% at follow-up. At outcome the CPT + FST group showed the largest increase in ARAT score and this was above the clinically important level of 5.7 points. Median (interquartile range) increases were 11.5 (21.0) for CPT; 8.0 (13.3) for CPT + CPT; and 19.5 (22.0) for CPT + FST. The estimated sample size for an adequately powered subsequent phase III trial was 279 subjects at outcome.
                Further work toward a phase III clinical trial appears justifiable.
There is insufficient evidence to support inspiratory muscle training as an effective treatment to improve function after stroke, and no evidence relating to the safety of inspiratory muscle training. Further well-designed RCTs are required.