High-intensity inspiratory muscle training in patients with chronic obstructive pulmonary disease and severely reduced function

PURPOSE: This study examined the effects of inspiratory muscle training (IMT) with high-intensity inspiratory pressure loads on respiratory muscle performance and exertional dyspnea. METHODS: This was a randomized single-blind clinical trial. Twenty-seven patients with chronic obstructive pulmonary disease (18 men, 9 women) with severe to very severe airflow obstruction and severely limited functional performance were assigned randomly to an IMT group (n = 12) or an educational control group (n = 15). The IMT group trained with a threshold loaded device for 30 minutes a day for 16 weeks using interval training techniques. Training was initiated with inspiratory pressure loads equal to 30% of maximal inspiratory pressure (Plmax) and increased as tolerated to 60% of Plmax. Dependent variables were measured before and after 4 months of IMT: inspiratory muscle strength (Plmax), respiratory muscle endurance (discontinuous incremental threshold loading test [DC-ITL]), dyspnea (Chronic Respiratory Disease Questionnaire [CRQ]), and the Borg Category-Ratio Scale ratings of perceived breathing difficulty (RPBD) at equal loads during the DC-ITL. RESULTS: In the IMT group, Plmax increased from 64 +/- 15 to 75 +/- 17 cm H2O (P < .05), performance on the DC-ITL test increased from a maximal load of 37 +/- 12 to 53 +/- 13 cm H2O (P < .05), RPBD decreased from 5.5 +/- 2.5 to 3.8 +/- 2.6 for equal loads on the DC-ITL (P < .05) and the CRQ Dyspnea Scale improved from 18.1 +/- 5.1 to 22.4 +/- 5.2 (P < .05). CONCLUSIONS: Inspiratory muscle training at high-intensity loads significantly improved inspiratory muscle strength, respiratory muscle endurance, and respiratory symptoms during daily activities and respiratory exertion.     

Home respiratory muscle training in patients with chronic obstructive pulmonary disease

OBJECTIVE AND BACKGROUND: The benefits of inspiratory muscle strength training in decreasing symptoms, disability or handicap of patients affected by COPD are not well established. The objective of this study was to assess the efficacy of the constant use of a new flow-volumetric inspiratory exerciser, named Respivol, in improving respiratory functional parameters in COPD patients. METHODS: Twenty consecutive ambulatory patients affected by COPD were enrolled. Each patient was assessed, before and after 3 and 6 months inspiratory exercise with Respivol, for the following clinical parameters: maximal inspiratory pressure, maximal expiratory pressure, dyspnoea grade, quality of life by a self-administered St George questionnaire and a 6-min walking test. After a brief progressive ambulatory training programme, inspiratory exercise with Respivol was performed at home for 6 months. All patients used Respivol together with medical treatment. RESULTS: Maximal inspiratory pressure and maximal expiratory pressure values were significantly increased after 3 and 6 months of exercise. Dyspnoea grade was significantly reduced and the 6-min walking test showed an increase in effort tolerance, after 6 months of home training. Quality of life assessment showed an improvement, associated with a decrease of respiratory disease symptoms. CONCLUSIONS: Inspiratory muscle strength training with Respivol seems to be efficient in reducing symptoms and improving quality of life in adults with COPD.     

Cycle ergometer and inspiratory muscle training in chronic obstructive pulmonary disease.

In patients with chronic obstructive pulmonary disease (COPD) the intensity of aerobic training is limited by dyspnea. Improving strength of the inspiratory muscles could enhance aerobic exercise training by reducing exercise-related dyspnea. We examined effects of home-based inspiratory muscle training (IMT) and cycle ergometry training (CET) in 53 patients with moderate to severe COPD (FEV(1)% pred, 50 +/- 17 [mean +/- SD]). Patients were randomly assigned to 4 mo of training in one of four groups: IMT, CET, CET + IMT, or health education (ED). Patients were encouraged to train to the limits of their dyspnea. Inspiratory muscle strength and endurance increased in IMT and CET + IMT groups compared with CET and ED groups (p < 0. 01). Peak oxygen uptake increased and heart rate, minute ventilation, dyspnea, and leg fatigue decreased at submaximal work rates in the CET and CET + IMT groups compared with the IMT and ED groups (p < 0. 01). There were no differences between the CET and CET + IMT groups. Home-based CET produced a physiological training effect and reduced exercise-related symptoms while IMT increased respiratory muscle strength and endurance. The combination of CET and IMT did not produce additional benefits in exercise performance and exercise-related symptoms. This is the first study to demonstrate a physiological training effect with home-based exercise training.     

Inspiratory muscle training in patients with chronic obstructive pulmonary disease

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 less than 0.005). Training slightly increased inspiratory muscle strength (p less than 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.     

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.     

Effects of transdermal tulobuterol on dyspnea and respiratory function during exercise in patients with chronic obstructive pulmonary disease

Background

Poor exercise tolerability is a major barrier to improving the quality of life of patients with chronic obstructive pulmonary disease (COPD). Although COPD is often treated with long-acting β₂ adrenergic agonists, few studies have examined their effects on exercise tolerability.

Methods

In this study, Japanese COPD patients were treated with 2 mg transdermal tulobuterol, a long-acting β₂ agonist, once daily for 4 weeks. Spirometry and exercise tests were conducted at baseline and at the end of treatment. The patients conducted constant load (30 W for 5 min) and incremental load (starting at 10 W and increasing by 10 W every 1 min for 5 min to a maximum load of 50 W) exercise tests on a cycle ergometer.

Results

Thirteen patients with stable COPD participated in this study (mean age ± standard deviation (SD), 69.5±9.7 years; smoking history 55.9±27.8 pack-years). Resting spirometric parameters were unchanged at the end of treatment. The maximum Borg scale for dyspnea and the Borg scale slope (BSS) decreased significantly from baseline to the end of treatment. The threshold load of dyspnea (TLD) increased slightly, although not significantly, in the constant load test but not in the incremental load test. There were no changes in respiratory parameters during exercise after treatment.

Conclusions

In conclusion, we found that treatment with transdermal tulobuterol for 4 weeks improved self-assessed dyspnea in Japanese COPD patients during constant and incremental exercise tests. This improvement in dyspnea may encourage patients to perform daily life activities or regular physical activity.     

慢性阻塞性肺疾病呼吸肌功能不全发病机制

研究发现慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)患者由于肺气肿、慢性低氧、高碳酸血症、营养不良及医源性因素等多种原因,呼吸肌尤其是膈肌可出现肌纤维发生结构及功能变化,导致呼吸肌功能不全.呼吸肌功能不全是发生呼吸衰竭的重要的病理生理机制之一.本文对COPD发生呼吸肌功能不全机制进行综述.     

呼吸康复训练对慢性阻塞性肺疾病患者的影响

目的 探讨呼吸康复训练对慢性阻塞性肺疾病(COPD)患者炎症反应、氧化应激治疗及急性加重风险的影响.方法 选择2017年3月至2018年4月我院接受治疗的中重度COPD稳定期患者47例,分为常规治疗组22例和呼吸康复组25例;常规治疗组给予抗炎、氧疗、止咳化痰、长效支气管扩张药物治疗;呼吸康复组在常规治疗基础上辅以呼吸...     

Dyspnea and inspiratory muscle function during exercise in severe chronic obstructive pulmonary disease (COPD)]

Role of inspiratory muscle function in the genesis of dyspnea in COPD patients has yet to be fully studied. The present study investigated the possible relationship between respiratory muscle function and the sensation of dyspnea (modified Borg Scale) during exercise in eight patients with severe COPD (FEV1 0.61L +/- 0.15L). The electrical activity of the diaphragm (EMGdi) was recorded with esophageal electrodes, and that of sternomastoid muscle (EMGsm) was recorded from the surface electrodes. The ratio of high frequency (150 to 350 Hz) to low frequency (20 to 47 Hz) power (H/L) of EMGdi and EMGsm was analyzed to assess inspiratory muscle fatigue, which was determined by a 20% fall of H/L ratio from the control value. Flow, volume, esophageal (Pes) and transdiaphragmatic pressure (Pdi) were measured. Tension time index (TTdi) was calculated from Pdi and the ratio of inspiratory time to total time for one cycle (T1/TTOT). At rest, we measured maximal esophageal pressure (Pesmax), maximal transdiaphragmatic pressure (Pdimax), maximal EMGdi (EMGdimax) and EMGsm (EMGsmmax). Progressive treadmill exercise test was performed, stating with 3 minutes' walk at a speed of 0.75 mph at 0% grade, subsequently increasing the velocity at a rate of 0.25 mph and the elevation at a rate of 4% per stage. Exercise was discontinued at maximum respiratory effort sensation. Six of the eight patients showed diaphragmatic fatigue at their maximal exercise. With diaphragmatic fatigue, these patients were extremely dyspneic (Borg scale 9 or 10), and terminated the exercise. There were high correlations between the Borg scale and VE/MVV, and Pes/Pesmax and EMGsm/EMGsmmax, however, TTdi and EMGdi/EMGdimax showed less correlation with the Borg scale.(ABSTRACT TRUNCATED AT 250 WORDS)     

踏车锻炼对慢性阻塞性肺疾病患者吸气肺功能的影响及与运动能力改善的关系

目的 探讨踏车锻炼对慢性阻塞性肺疾病(COPD)患者吸气肺功能的影响及与运动能力改善的关系.方法 对12例中、重度COPD患者进行12周的下肢踏车运动训练.在运动训练前后分别进行常规肺通气功能、弥散功能、肺容积、最大用力吸气峰流速(PIF)、最大吸气压(MIP)、症状限制递增功率心肺运动试验和高强度恒定功率心肺运动试验.在高强度恒定功率运动中,每隔1 min记录受试者潮式呼吸流速-容积(TBFV)曲线.结果 踏车锻炼后COPD患者运动持续时间(T)(t=7.357,P＜0.001)和峰运动功率(WRpeak)(t=3.614,P＜0.05)显著增加;MIP(t=4.754,P＜0.001)和PIF(t=2.440,P＜0.05)显著增加;踏车锻炼后COPD患者在等时间点潮式呼吸吸气峰流速(t=-2.747,P＜0.05)和呼气峰流速(t=-4.487,P＜0.05)均较前显著下降,最大吸气流速储备较前显著增加(t=2.755,P＜0.05),最大呼气流速储备较前无显著变化(t=1.326,P＞0.05).受试者下肢踏车锻炼后MIP的增加(r=0.613,P＜0.05)、PIF的增加(r=0.497,P＜0.05)和等时间点最大吸气流速储备的增加(r=0.592,P＜0.05)分别与运动持续时间的增加呈显著正相关.结论 下肢运动训练可改善COPD患者吸气肺功能指标;运动训练后吸气肌肉力量、PIF和运动中吸气流速储备的增加可能是COPD患者运动能力改善的主要原因.

Abstract：

Objective To explore the effect of treadmill training on inspiratory function and its association with improvement of exercise capacity in patients with chronic obstructive pulmonary disease (COPD). Methods The 12 moderate to severe COPD patients were allocated to lower-limb exercise training for 12weeks. The routine tests of pulmonary ventilation function, diffusion function,lung volume, peak inspiratory flow (PIF), maximal inspiratory pressure (MIP), symptom-limited progressive cycle ergometer exercise tests and constant work rate exercise tests were administered before and after the training program. During the constant work rate exercise tests, tidal breathing flow volume (TBFV) curves were recorded every 1 mir. Results After treadmill training, the exercise duration (T) (t=7. 357, P＜0. 001), peak work rate (WRpeak) (t=3. 614, P＜0.05), MIP (t=4.754, P＜0. 001) and PIF (t=2. 440, P＜0. 05) increased significantly. The tidal PIF (t=- 2.747, P＜0.05) and peak expiratory flow (PEF) (t = - 4.487, P＜ 0.05 ) decreased significantly at isotime. Maxium inspiratory flow reserve (△FLOWinsp) (t = 2. 755, P ＜ 0. 05 ) increased significantly at isotime, and maxium expiratory flow reserve (△FLOWexp) (t = 1. 326, P ＞ 0.05)showed no significant changes; The△T were positively correlated with △MIP (r=0. 613, P＜0. 05),△PIF (r=0.497, P＜0.05) and △FLOWinsp (r=0.592, P＜0.05). Conclusions Lower limb exercise training improves inspiratory function of COPD patients. The improvement of exercise endurance in moderate to severe COPD patients after lower limb exercise training is due to increases of inspiratory muscle strength, maxium PIF and inspiratory flow reserve.     

慢性阻塞性肺疾病的呼吸肌功能

慢性阻塞性肺疾病患者常存在呼吸肌收缩力和(或)耐力下降,引起呼吸困难,限制患者活动能力,使患者的运动量减少,日常生活质量降低;如果病情得不到控制,可以导致高碳酸性呼吸衰竭,严重者造成患者死亡.呼吸肌功能评价在慢性阻塞性肺疾病患者临床病情评估和预后判断方面很有应用价值.最大吸气压和最大呼气压测定是临床最常用的、可信的、非创伤性的评价呼吸肌功能的指标.研究结果显示最大吸气压较一秒量敏感.呼吸肌本身的病理改变和肺过度充气导致膈肌的收缩初长度缩短等原因可以引起呼吸肌功能障碍.可以应用抗胆碱药物、β2-受体激动剂、运动训练、营养支持及同化激素、心理支持、患者教育等治疗慢性阻塞性肺疾病呼吸肌功能障碍.蛋白酶抑制剂、过氧化物酶体增殖物激活受体、硫酸镁有希望成为治疗慢性阻塞性肺疾病呼吸肌功能障碍的方法.     

慢性阻塞性肺疾病稳定期呼吸功能锻炼

慢性阻塞性肺疾病（chronic obstructive pulmonarydisease,COPD）是以慢性不完全可逆气流阻塞为特征的一组疾病,是严重危害老年人健康的常见慢性病。COPD发展到一定阶段,肺弥散功能常受到损害,运动耐量或最大有氧代谢能力明显降低。     

Noninvasive ventilation during exercise training improves exercise tolerance in patients with chronic obstructive pulmonary disease

PURPOSE: In patients with chronic obstructive pulmonary disease, pulmonary rehabilitation has been demonstrated to increase exercise capacity and reduce dyspnea. In the most disabled patients, the intensity of exercise during the training sessions is limited by ventilatory pump capacity. This study therefore evaluated the beneficial effect of noninvasive ventilation (NIV) support during the rehabilitation sessions on exercise tolerance. METHODS: This study included 14 patients with stabilized chronic obstructive pulmonary disease, ages 63 +/- 7 years, with a forced expiratory volume in 1 second (FEV(1)) 31.5% +/- 9.2% of predicted value. All 14 patients participated in an outpatient pulmonary rehabilitation program. Seven of the patients trained with NIV during the exercise sessions (NIV group), whereas the remaining seven patients breathed spontaneously (control group). Exercise tolerance was evaluated during an incremental exercise test and during constant work rate exercise at 75% of peak oxygen consumption (VO(2)) before and after the training program. RESULTS: The application of noninvasive ventilation increased exercise tolerance, reduced dyspnea, and prevented exercise-induced oxygen desaturation both before and after training. The pressure support was well tolerated by all the patients during the course of the training program. In the NIV group, training induced a greater improvement in peak VO(2) (18% vs 2%; P <.05) and a reduced ventilatory requirement for maximal exercise, as compared with the control group. The constant work rate exercise duration increased similarly in both groups (116% vs 81%, nonsignificant difference), and posttraining blood lactate was decreased at isotime (P <.05 in both groups), but not at the end of the exercise. CONCLUSION: In this pilot study, exercise training with noninvasive ventilation support was well tolerated and yielded further improvement in the increased exercise tolerance brought about by pulmonary rehabilitation in patients with chronic obstructive pulmonary disease. This improved exercise tolerance is partly explained by a better ventilatory adaptation during exercise.     

Effects of intermittent negative pressure ventilation on respiratory muscle function in patients with severe chronic obstructive pulmonary disease

The reduced respiratory muscle strength and increased work of breathing in patients with severe chronic obstructive pulmonary disease (COPD) may predispose these patients to the development of respiratory muscle fatigue and consequent respiratory failure. To test the hypothesis that these patients may be experiencing chronic respiratory muscle fatigue, we studied the effects of resting the respiratory muscles in a group of patients with severe COPD. Fifteen stable patients with severe COPD were randomized into study and control groups. In 8 study group patients (Group B), breathing was assisted with a negative pressure ventilator 3 to 6 h daily for 3 consecutive days. The remaining 7 patients served as controls (Group A) and did not receive any intervention. Baseline lung function was evaluated by spirometry and arterial blood gas determinations. Respiratory muscle strength and endurance were evaluated by maximal inspiratory and expiratory pressures (MIP and MEP, respectively) and the maximal duration that isocapnic hyperventilation equal to 50 and 70% of the 12-s maximal voluntary ventilation could be sustained (DSV). Baseline DSV was determined as the best effort of several practice trials. All measurements were repeated on the final day of assisted ventilation approximately 2 to 3 h after its discontinuation. After assisted ventilation, the DSV at 50 and 70% of the maximal voluntary ventilation improved significantly (p less than 0.05). Maximal inspiratory pressure and MEP increased to 114% (p less than 0.05) and 112% (p = 0.05) of baseline values, respectively. Mean arterial PCO2 in the hypercapnic subgroup of Group B patients decreased from 60 mm Hg before to 52 mm Hg after assisted ventilation (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of refeeding on peripheral and respiratory muscle function in malnourished chronic obstructive pulmonary disease patients

We carried out a prospective randomized controlled trial to investigate the effects of short-term refeeding (16 days) in 10 malnourished inpatients with chronic obstructive pulmonary disease (COPD). Six patients were randomized to receive sufficient nasoenterically administered calories to provide a total caloric intake equal to 1,000 kcal above their usual intake. The other four patients were sham fed, receiving only 100 kcal more. Measurements of nutritional status, respiratory muscle strength and endurance, adductor pollicis function, and pulmonary function were performed initially and at study end. The refed group gained significantly more weight and showed significant increases in maximal expiratory pressure and mean sustained inspiratory pressure. There were no significant changes in the maximal inspiratory pressure or in adductor pollicis function. In malnourished inpatients with COPD, short-term refeeding leads to improvement in respiratory muscle endurance and in some parameters of respiratory muscle strength in the absence of demonstrable changes in peripheral muscle function.     

深吸气量的测定在慢性阻塞性肺疾病患者中的临床意义

目的探讨肺功能指标深吸气量的测定在慢性阻塞性肺疾病患者中的临床应用价值。方法对21例COPD患者肺功能测定和支气管舒张试验,比较吸入沙丁胺醇200μg前后各肺功能指标的变化,并比较各指标在支气管扩张试验阳性组与阴性组、阻塞程度较中度组与重一极重度组的组中和组间差异性。结果在各项肺功能指标中,仅IC、FVC和FEV1在吸药后增加,其中IC的增加幅度最大。舒张试验阳性组和阴性组IC皆明显增加,且增加幅度相似。IC的增加幅度在重—极重度组大于轻—中度组。结论IC的增加与舒张试验的阳性和阴性结果没有必然的关联,可作为独立指标。支气管扩张剂缓解呼吸困难症状和增加运动耐力的作用在阻塞程度较重者更明显。     

Resistive breathing training in patients with chronic obstructive pulmonary disease

In order to investigate the effect of resistive breathing training on ventilatory muscular endurance, we examined the maximal sustained ventilatory capacity in ten patients with chronic obstructive pulmonary disease (COPD) before and after a six-week program of resistive breathing training. In addition, we investigated the effect of altered breathing strategy on resistive breathing performance. The patients performed two 15-minute sessions of resistive breathing daily for six weeks using an inspiratory resistive device (Pflex). Before and after the training, we found no significant change in spirometric data, pulmonary volumes, maximal inspiratory pressure, and maximal expiratory pressure. Of the ten patients, seven failed to show an improvement in their performance of resistive breathing. Furthermore, the maximal sustained ventilatory capacity was unchanged after the resistive breathing training. After the completion of the training program, seven of the patients participated in an additional experiment in which they were instructed to take long slow inspirations while breathing through the resistive device. With this change in breathing pattern, five of the seven were able to improve their performance of resistive breathing. Analysis of the breathing strategy showed that a reduction in the peak mouth pressure, breathing frequency, and external resistive work with a longer inspiratory time was beneficial. We conclude that neither resistive breathing performance nor ventilatory muscular endurance, as measured by sustained hyperpnea, is improved by resistive breathing training performed according to the current instructions with the resistive device, and alterations in breathing strategy have a profound effect on the performance of resistive breathing. The lack of details of breathing strategy in previous studies of resistive breathing makes it difficult to determine if previously demonstrated improvements were due to a real enhancement of ventilatory muscular performance or merely secondary to a different strategy.