Respiratory Muscles After Inspiratory Muscle Training After COVID-19
Condition: COVID-19; Diaphragm Injury
MeSH terms: COVID-19
Study type: Interventional

Summary: 
      It is the aim of the current (follow-up) project for the first time in post-COVID-19 patients
      who continue to complain of shortness of breath and for whom there is no other explanation
      than possibly proven diaphragmatic weakness, to determine the effects of 6 weeks of
      IMT/diaphragm training on diaphragm strength and shortness of breath.
    

Detailed description: 
      Breathing is a complex process involving muscular, neurological and chemical processes in the
      body. Herein, the respiratory muscles play a very important role.

      The respiratory muscles are the muscle groups that cause the expansion and contraction of the
      chest during inhalation and exhalation. The most important respiratory muscle is the
      diaphragm. It is known that long-term ventilation in the intensive care unit weakens the
      respiratory muscles, since the work of the muscles is taken over by the ventilation devices
      and the muscles are not trained over a long period of time.

      As recently shown, COVID-19 disease can lead to diaphragmatic weakness even in the absence of
      ventilation.

      In this project (CTCA 20-515) the present investigators demonstrated that several patients
      after COVID-19 suffer from diaphragmatic weakness. Specifically, diaphragmatic weakness also
      related to shortness of breath complained about by patients and currently not otherwise
      explainable.

      The so-called inspiratory muscle training (IMT or diaphragm training) is known in
      pneumological rehabilitation for years. In the current project, after the training has been
      explained, the patient is asked to breathe against resistance at home using a small
      mouthpiece and a small device several times (twice) a day and several times a week (each
      day).

      This procedure is considered safe and very effective in training the diaphragm. Accordingly,
      it is the aim of the current (follow-up) project for the first time in post-COVID patients
      who continue to complain of shortness of breath and for whom there is no other explanation
      than possibly the proven diaphragmatic weakness, to determine the effects of 6 weeks of
      IMT/diaphragm training on diaphragm strength and on shortness of breath.

      At the beginning and at the end of the 6 weeks of training, the present investigators would
      carry out the all-encompassing measurement of diaphragm force, which is known to patients and
      explained again below. Furthermore, the present investigators would invite patients twice a
      week to optimize the training together (for a maximum of 1 hour per appointment). This would
      take place once a week in the present investigators laboratory for respiratory physiology and
      the training would be improved it if necessary, once a week.

      The training would end after 6 weeks and the present investigators would measure diaphragm
      function again 6 weeks after the training, i.e. a third time in total, to determine whether
      the effects seen continue to be present after the training. After that, the study ends.

      The present investigators would offer the treatment arm (the 9/18 patients) in whom diaphragm
      endurance training was carried out as a control of the diaphragmatic strength training to
      carry out strength training after the measurement 6 weeks after the end of the therapy
      (outside of this study here as a purely clinical therapy).

      The training itself includes 2 x 30 breathing cycles per day. Patients can divide these 2 x
      30 breathing cycles freely, i.e. specifically train 1 x 30 breathing cycles in the morning
      and 1 x 30 breathing cycles in the afternoon. The whole training should take place daily, 7
      days a week.

      Once a week the present investigators get a picture of the patient's training, pay attention
      to shortness of breath, potential for adaptation (also specifically for even stronger
      training, if tolerated by the patients, increase in training, i.e. the breathing resistance
      that patients would have to overcome when inhaling ).

      In the "control" arm of the study, this force adjustment would not take place, i.e. it is an
      endurance training of the diaphragm with, however, also the control dates of the training
      twice a week. At least in the 6 weeks of the study (see above).
    

Intervention name(s): Inspiratory Muscle Training (IMT)
Intervention type(s): Device
Intervention description(s): The training itself includes 2 x 30 breathing cycles per day. The whole training should take place daily, 7 days a week. The initial training intensity in the treatment arm (resistance of the respiratory muscle training) is set to 50% of the maximum respiratory muscle strength (measured using PImax). Once a week the present investigators get a picture of patient's training, pay attention to shortness of breath, potential for adaptation.
In the "control" arm of the study, this force adjustment would not take place, i.e. it is an endurance training of the diaphragm (10% of PI Max over the whole 6 weeks) with, however, also the control dates of the training twice a week. At least in the 6 weeks of the study (see above).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment