Reduced inspiratory muscle strength is common in people with chronic obstructive pulmonary disease (COPD) and is associated with dyspnea and decreased exercise capacity. Most studies of inspiratory muscle training (IMT) in COPD have demonstrated increased inspiratory muscle strength. Many have also shown improvements in dyspnea and exercise capacity. However, a persisting challenge when translating and applying the findings of these studies in clinical practice is the disparity in training loads, modalities, and outcomes measures used in the different studies. This commentary summarizes our clinical and research experience with a threshold IMT device with the aim of providing clinicians interested in prescribing IMT in this population with practical recommendations regarding patient selection, assessment, and implementation of training. We propose using an interval-based high-intensity threshold IMT program for people who are unable to participate fully in whole-body exercise training because of comorbidities such as severe musculoskeletal problems. Initial training loads equivalent to at least 30% of a person's maximum inspiratory pressure (PImax) are required for all people undertaking IMT. Supervision, which includes monitoring of oxygen saturation throughout the first training session, is recommended, and patients are warned to expect transient delayed-onset muscle soreness, a consequence of muscle adaptation to an unaccustomed activity. We recommend training be undertaken 3 times a week for 8 weeks, with loads progressively increased as symptoms permit. It is prudent to exclude people at risk of pneumothorax or spontaneous rib fracture. Evaluation of IMT should include measures of PImax, dyspnea, health-related quality of life, and exercise capacity.
PMID: 20801269 DOI: 10.1016/j.apmr.2010.06.010

To investigate the effects of inspiratory muscle resistive loading training (IMT) on exercise performance in chronic obstructive pulmonary disease (COPD), 13 patients undergoing standard pulmonary rehabilitation were divided into control (n=6) and experimental (n=7) groups. Prior to training, we measured inspiratory muscle strength and endurance, resting pulmonary function, and exercise performance on a bicycle ergometer (a progressive test and an endurance test at two thirds of maximal work load). We then determined their resistive loads for training by measuring their 10-min maximal sustainable resistance. Training by patients in the experimental group involved inspiring against a predetermined resistive load. The control subjects breathed through a sham training tube, so that studies were performed in double-blind fashion. The training consisted of 15-min sessions twice daily for 4 wk. The IMT dramatically improved inspiratory muscle endurance—represented as either sustainable inspiratory pressure (SIP) or endurance time at 60% of maximal inspiratory mouth pressure (Pimmax) at functional residual capacity. The SIP of the trained group increased from 29 ± 11 to 46 ± 11% of Pimmax (p < 0.005). Training slightly increased inspiratory muscle strength (p < 0.05), as determined by Pimmax. In contrast, resting pulmonary function and performance of both progressive and constant-load exercise remained unchanged. We conclude that 4-wk IMT in a pulmonary rehabilitation setting improves inspiratory muscle endurance in patients with COPD without changing pulmonary function or exercise performance.
PMID: 3970455 DOI: 10.1164/arrd.1985.131.2.251

Most pulmonary rehabilitation (PR) programs do not currently incorporate IMT in their PR programs for COPD patients. The aim of the present study was to assess the influence of adding IMT to the patients already involved in a rehabilitation program. Thirty-four patients with significant COPD were recruited for the study. All patients participated in a general exercise reconditioning (GER) program for 12 weeks. The patients were then randomized to receive IMT or sham IMT, in addition to GER for the next 6 months. Following three months of GER training there was a significant increase in the 6-min walk test (6MWT) (from mean+/-SEM 254+/-38 to 322+/-42 m, p<0.01), and small but non-significant decreases in the perception of dyspnea (POD), and in the St. George Respiratory Questionnaire score (SGRQ). Following the addition of IMT to the GER program there was a significant increase in the PI(max) in the GER+IMT group (from 66+/-4.7 to 78+/-4.5 cm H(2)O, p<0.01). This was accompanied by a significant improvement in the POD and a further significant improvement in the SGRQ score. IMT provides additional benefits to patients undergoing PR program and is worthwhile even in patients who have already undergone a GER program.
PMID: 17329091 DOI: 10.1016/j.rmed.2007.01.010

AIM: The aim of this study was to evaluate the impact a specific inspiratory muscle training (IMT) protocol had on dyspnoea, lung function, respiratory muscle pressure, tolerance to exercise and quality of life in a group of patients with chronic obstructive pulmonary disease (COPD) POPULATION: We studied 13 patients with moderate to very severe COPD divided into a control group (n=5) with an average FEV1 43.9 +/- 10.1% of predicted value and an IMT group (n=8) with FEV1 57.8 +/- 12.1 % of predicted value. While this study group underwent IMT for five consecutive weeks, the control group did not undergo any kind of training.
RESULTS: Using a specific IMT protocol significantly improved maximal inspiratory pressure (MIP) in the study group (initial MIP - 83.3+/- 21.4 versus final MIP- 98.4+/-17.8 cmH2O;p<0.01). The same result was seen with the St. George Respiratory Questionnaire (SGRQ) score in the study group (initial score 58+/-2.2 versus final score 50+/-2.1; p<0.05). No changes were recorded in the variables studied in the control group.
CONCLUSIONS: The use of IMT in patients with moderate to very severe COPD induced an improvement in inspiratory muscle force with a consequent improvement in the quality of life in relation to symptoms.
PMID: 18363017

AIM: The aim of this study was to answer the question: is there an effect on the respiratory capacity and activity tolerance of older patients with chronic obstructive pulmonary disease who participate in a pulmonary rehabilitation programme?
BACKGROUND: Pulmonary rehabilitation is now an integral part of chronic obstructive pulmonary disease management. Evidence supports the positive effects of breath training and exercising training on quality of life, exercise tolerance and improved physical condition of individual with chronic obstructive pulmonary disease. Limited empirical documentation exists to support the effectiveness of a nurse managed rehabilitation programme for older patients with chronic obstructive pulmonary disease. The study was done to evaluate the effects of pulmonary rehabilitation provided by nurses on the pulmonary function, gas exchange and exercise tolerance in older patients with chronic obstructive pulmonary disease.
DESIGN: A one group pre-test-post-test design was used to evaluate the effects of a pulmonary rehabilitation programme.
METHOD: The sample consisted of 20 patients with chronic obstructive pulmonary disease who participated in a pulmonary rehabilitation programme including breathing exercises, upper-limb exercises and inspiratory muscle training.
RESULTS: The findings indicated improvement in exercise performance and a decrease in dyspnea after participation in the pulmonary rehabilitation programme.
RELEVANCE TO CLINICAL PRACTICE: The clinical nurse can make a significant impact on the illness trajectory and quality of life for patients with chronic obstructive pulmonary disease. The nurse has a critical role in helping patient with chronic obstructive pulmonary disease learn to cope, adjust and adapt to life with a chronic illness. Active nurse involvement with a patient in a pulmonary rehabilitation programme can assist in the identification of factors that motivate the patient, help in establishing realistic out comes expectations and provide patient teaching opportunities. The nurse can assist the patient to develop skills of self-awareness regarding particular symptoms, self-monitoring and health status change identification.
PMID: 17394540 DOI: 10.1111/j.1365-2702.2006.01712.x