Ventilatory Muscle Training in Stroke
Condition: Stroke; Pulmonary Ventilation; Exercise Therapy
MeSH terms: Stroke
Study type: Interventional
Phase: Phase 3

Summary: 
      The purpose of the present study is to determine the utility and effectiveness of combined
      inspiratory (IMT) and expiratory muscle training (EMT) in improving ventilatory function in
      people who are disabled by long-term stroke (greater than 8 months following onset) with
      hemiparesis or hemiplegia. xx subjects will be randomized into 2 parallel groups in which the
      experimental group will undergo combined IMT and high-resistance EMT and the comparison group
      will undergo IMT with low- resistance EMT. Both training techniques involve breathing through
      a tube with known amounts of resistance. Subjects will perform the breathing maneuvers for 10
      repetitions, twice daily, 5 days per week for 4 weeks, in the home environment. Adherence
      will be monitored by reminder telephone calls at least weekly. Outcomes will be assessed
      using maximum inspiratory and expiratory pressures and standard pulmonary function testing.
    

Detailed description: 
      The purpose of the present study is to determine the utility and effectiveness of Expiratory
      Muscle Training in improving respiratory muscle strength in patients with chronic stroke,
      when combined with Inspiratory Muscle Training.

      20 participants will be recruited from one site (Rehabilitation Institute of Chicago). All
      participants will give written informed consent before the enrollment in the study.
      Participants will be compensated for their participation.

      Participants will participate in the study for one month. Maximum inspiratory and expiratory
      pressures will be measured in the seated position. Pulmonary function testing will also be
      performed in the seated position using a spirometer. Dyspnea will be assessed by the Medical
      Research Council (MRC) dyspnea scale.

      The initial evaluation will consist of recording demographic information and conducting a
      comprehensive medical history, including: age, gender, race, marital status, education,
      employment, smoking history, ischemic stroke etiology, stroke severity with NIH Stroke Scale,
      and stroke location. This information may also be obtained from the RIC electronic medical
      record. Each subject will undergo a thorough neurologic assessment.

      Study participants will be randomly assigned to one of two groups: the experimental group
      with high resistance EMT and the control group with low resistance EMT. The participants will
      be randomized to the two groups by an independent staff member at the time of enrollment
      based on the medical record number. Both groups will undergo IMT because IMT has been found
      to be effective improving MIP as well as FEV1 and FVC. The patients and those reading the
      pulmonary function tests will be blinded to the group assignment of each participant.

      Upon enrollment in the study, respiratory muscle training will be completed twice daily for 5
      days a week for 4 weeks. Training will be provided with the Threshold IMT (Respironics,
      Murrysville, PA) for inspiratory training and Threshold PEP (Respironics, Murrysville, PA)
      for expiratory training. The Threshold respiratory trainers are commercially available
      devices with a spring-loaded valve that provided resistance. The pressure loads can be
      adjusted at 2 cm H2O intervals for the Threshold IMT, up to 41 cm H2O, and 1 cm H2O intervals
      for the Threshold PEP, up to 20 cm H2O. EMT training loads in the experimental group will be
      set to 30% of maximal expiratory pressure while the control group EMT will be set to 5 cm
      H2O, the lowest setting on the device. IMT training loads will be set to 30% of maximal
      inspiratory pressure for both groups. The patient will be blinded to the valve titration.
      Each training session will include one set of 10 repetitions with IMT followed by one set of
      10 repetitions with high resistance EMT or low resistance EMT. Patients will be instructed to
      maintain a respiratory rate of 15-20 breaths/min without rest between repetitions.
      Participants will be monitored daily by phone and by self-reported log for completion of each
      training. At two weeks, participants will have a follow-up office visit to monitor progress
      and those that have completed 80% of their training sessions will increase their training to
      40% of maximum inspiratory and expiratory pressures as tolerated.

      Each participant will undergo baseline measurement of maximal inspiratory and expiratory
      pressure and baseline pulmonary function tests as well as after 4 weeks of training. Three
      trials will be performed with the highest result of the three trials recorded.
    

Intervention name(s): IMT with High Resistance EMT; IMT with Low Resistance EMT
Intervention type(s): Behavioral; Behavioral
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment