Inspiratory Muscle Training on Respiratory Muscle Function，Quality of Life and Exercise Capacity in Stable COPD
Condition: COPD
MeSH terms: Respiratory Aspiration
Study type: Interventional

Summary: 
      Comparable RCTs of clinical therapeutic effects using respiratory physiology-oriented IMT
      device in different operation principle in COPD are so far lacking. Therefore the
      investigators perform an adequately powered RCT on the effects of two IMT device application
      as an pulmonary physical therapy in patients with COPD with inspiratory muscle weakness.
    

Detailed description: 
      Chronic obstructive pulmonary disease (COPD) is defined as sustained expiratory flow
      limitation small airway disease which is a major cause of morbidity and mortality worldwide.
      Dyspnoea is the most vital symptom lead to exercise-limiting of COPD which is the major
      reason of physical activities reduction and consequently contribute to dysfunction of
      skeletal muscle including diaphragm. Diaphragm sarcopenia is well documented as an important
      extrapulmonary manifestation of COPD. It has been suggested that reductions in exercise
      capacity are conversely related to the muscle weakness present in these patients and
      consequently impact negatively on quality of life. It also contributes to hypoxaemia and
      hypercapnia in progressive stage.

      Mutiple pulmonary rehabilitation programs are regular physical care for stable patients with
      COPD to improve extrapulmonary disease manifestations. Inspiratory muscle training (IMT)
      serve as one of pulmonary rehabilitation program that aim at diaphragmatic improvement has
      been used constantly and is extensively studied in recent years in stable patients with COPD.

      From meta-analyses of randomised controlled trials (RCTs) in patients with COPD, it can been
      concluded that IMT as a stand-alone therapy was proved to increase inspiratory muscle
      strength and endurance, decrease dyspnea, improve exercise capacity and the quality of life.
      It was also concluded that COPD patients with inspiratory muscle weakness which defined as
      PI,max< 60 cmH2O were more likely to significantly improve inspiratory muscle strength and
      functional exercise capacity when IMT was applied.

      IMT is defined as persistent breathing training using the inspiratory training device.
      Inspiratory muscle trainers were classified into inspiratory resistive trainers® and
      inspiratory threshold trainers® according to operation principle. The former contain build-in
      spring-loaded valve which provides a continuous, pre-determined inspiratory load during the
      entire inspiratory phase; The latter do not provide a constant inspiratory load to ensure the
      intensity of inspiratory training. There are great differences in operation principle between
      the two inspiratory muscle trainers above. Inspiratory resistance that generated by
      inspiratory resistive trainers depend on inspiratory flow rate, however threshold load is
      independent of inspiratory flow. Intensity of loads in the two IMT devices can be repectively
      adjust.

      However, therapic effect of IMT remains undefined due to disunity of IMT devices and loads in
      previous studies. Various devices and loads arouses different training intensity which is the
      key point of securing training effect. The optimized IMT program with proper devices and
      loads should be figure out. The investigators' previous study elaborated the detailed
      respiratory physiological response to IMT in COPD. Comparable RCTs of clinical therapeutic
      effects using respiratory physiology-oriented IMT device in different operation principle in
      COPD are so far lacking. Therefore the investigators perform an adequately powered RCT on the
      effects of two IMT device application as an pulmonary physical therapy in patients with COPD
      with inspiratory muscle weakness.
    

Intervention name(s): Threshold inspiratory muscle training; Resistive inspiratory muscle training; Control group
Intervention type(s): Device; Device; Other
Intervention description(s): Threshold inspiratory muscle training device (Threshold Inspiration Muscle Trainer, Respironics Inc; Pittsburgh, Pennsylvania, USA). The intensiy of IMT was adjusted and verification using Pm measurement in laboratory. Patients spontaneously breathed using resistive-IMT and their Pm were measured simultaneously. Adjusted the intensity of resistive-IMT from small to large according to the Pm waveform. Adjustment completed while mean Pm achieved 60% of MIP and maintained at least 15 minute. Likewise, eligible patients in these group used the resistive IMT device for 15 minutes, twice per day, with an inspiratory load at 60% of PImax as previously adjustment. Training loads were adjusted to maintain 60% of the PImax every week.; Resistive inspiratory muscle training device(PFLEX, Respironics Inc; Pittsburgh, Pennsylvania, USA). The intensiy of IMT was adjusted and verification using Pm measurement in laboratory. Patients spontaneously breathed using resistive-IMT and their Pm were measured simultaneously. Adjusted the intensity of resistive-IMT from small to large according to the Pm waveform. Adjustment completed while mean Pm achieved 60% of MIP and maintained at least 15 minute. Likewise, eligible patients in these group used the resistive IMT device for 15 minutes, twice per day, with an inspiratory load at 60% of PImax as previously adjustment. Training loads were adjusted to maintain 60% of the PImax every week.; Conventional therapy without any inspiratory muscle training program
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Treatment
Keywords: inspiratory muscle training