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Covid19RMA-COVID-19NCT06105450

Respiratory Muscle Assesment in COVID-patients Without Hospitalization

An observational study of Covid19 and Diaphragm Injury, run by RWTH Aachen University at 1 site in Germany.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Fatigue and exercise intolerance after survived COVID-19-infection might be related to weakness of the respiratory muscles. The aim of the project is to measure respiratory muscle function and strength in our respiratory physiology laboratory in patients who were not hospitalized during the acute COVID-19-infection… Read more about this study

Who is it for?
Ages 18 to 75 years
Conditions the study is for
Covid19, Diaphragm Injury
What is being tested?
Comprehensive assessment of respiratory muscle function.
How many people
25 participants
Where
1 siteGermany
Study dates
1 Dec 2024to 1 Dec 2024
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 75 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Study population: A total of 25 patients will be enrolled. Patients from the outpatient clinic of Department of Pneumology and Intensive Care UKA Aachen with a COVID infection at least six months ago without the need for hospitalization during the initial infection phase. Those patients will be compared with healthy controls (availaible data from pre-covid era) matched in a 3:1 ratio for age, sex and body mass index (BMI).

Who may be able to join

  • Patients with COVID-19 infection without hospitalization during the acute infection (n=25)
  • Patients aged at least 18 years, who are mentally and physically able to consent and participate into the study

Who cannot join

  • Clinically pre-established cardiovascular disease or other pulmonary diseases which might lead to exertional dyspnea (systolic heart failure, COPD).
  • Body-mass-index (BMI) >40
  • Expected absence of active participation of the patient in study-related measurements
  • Alcohol or drug abuse
  • Metal implant in the body that is not MRI compatible (NON MRI compatible pacemaker, implantable defibrillator, cervical implants, e.g. brain pacemakers etc.)
  • Slipped disc
  • Epilepsy
  • Bound to a wheel chair

Trial locations and contacts

1 site in 1 country.

Germany1 site

  • Jens Spiesshoefer

    Aachen, North Rhine-Westphalia

Other trials in Germany

About this study

Official title: Potential Role of Diaphragmatic Muscle Weakness as a Cause of Persistent Exertional Dyspnea in Patients With COVID-19 Disease Without Hospitalization

Fatigue and exercise intolerance after survived COVID-19-infection might be related to weakness of the respiratory muscles. The aim of the project is to measure respiratory muscle function and strength in our respiratory physiology laboratory in patients who were not hospitalized during the acute COVID-19-infection but still complain of different persistent symptoms including exertional dyspnea and fatigue.

Read the detailed description

Since the beginning of the COVID pandemic, more and more recovered patients have a number of persistent symptoms including exertional dyspnea and fatigue even months after recovering from acute coronavirus disease 2019 (COVID-19). These symptoms often cannot be explained because routine clinical diagnoses, including extensive cardiac and pulmonary examinations, do not reveal any relevant abnormalities.

In our previous study (Regmi et al) with 50 patients formerly hospitalized due to acute COVID-19 infection, it was shown that diaphragm muscle weakness contributes to persistent exertional dyspnea about one year after hospitalization for COVID-19, regardless of mechanical ventilation. Additionally, the severity of exertional dyspnea correlated with the extent of diaphragmatic weakness.

Since laboratory findings, pulmonary function tests and cardiological routine examinations did not reveal any significant impairments, this was the first time that a potential pathophysiological correlate is objectively associated with dyspnea in long COVID-19 syndrome. The results of our study were clinically relevant because the persistent symptom burden in patients after surviving COVID-19 infection remains very high. In addition diaphragm training presents itself as a potential therapeutic target, since in other diseases such as COPD, such training has been shown to improve the symptoms. Therefore, the investigators believe that the results provide important perspectives, both for the pathophysiological understanding and for the potential treatment of persistent exertional dyspnea in patients.

However, a considerable gap exists here: a significant number of patients who suffer from an acute COVID-19 infection but do not have a severe course during the initial infection, so that hospitalization is not necessary, still complain of different persistent symptoms. Here, too, despite an extensive cardiopulmonary work-up, there is a lack of a sufficient explanation of the lasting complaints. It is precisely in these patients that a possible role of diaphragmatic weakness on the symptoms is yet to be investigated using already established gold standard techniques.

Being tested
Comprehensive assessment of respiratory muscle function.
Keywords
Respiratory muscle functtion
Medical subject headings
COVID-19

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Comprehensive assessment of respiratory muscle function.Diagnostic test

    Comprehensive assessment of respiratory muscle function to the point of its invasive assessment with recordings of twitch transdiaphragmatic pressure in response to magnetic phrenic nerve stimulation and stimulation of the lower thoracic nerve roots.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Twitch transdiaphragmatic pressure in response to supramaximal magnetic stimulation of the phrenic nerve roots

    Recording of twitch transdiaphragmatic pressure (Unit: Pressure in cmH2O)

    Measured: 1 year

  2. Respiratory mouth pressures

    Measurement of respiratory (inspiratory and expiratory) mouth pressures (Unit: Pressure in cmH2O)

    Measured: 1 year

Secondary outcomes (4)

  1. Diaphragm ultrasound

    Comprehensive evaluation of diaphragm excursion (amplitude during tidal breathing, sniff maneuver and maximal inspiration in cm, corresponding velocity in cm/sec, respectively) and thickening on ultrasound (thickness at functional residual capacity, at total lung capactiy in cm), Markers of Diaphragm excursion and thickening will be combined to classify diaphragm function as normal, mildly, moderately or severly impaired.

    Measured: 1 year

  2. Exercise intolerance

    Comprehensive evaluation of symptoms (breathlesness based on NYHA class, on a visual scale ranging from 1-10, respectively) and exercise capacity (6 minute walking distance). These measurements will be combined to classifiy patients as presenting with exercise intolerance or no exercise intolerance.

    Measured: 1 year

  3. Lung function

    Comprehensive assessment of lung function by bodyplethysmography (most importantly forced vital capacity, forced expiratory volume after 1 second, intrathoracic gas volume, residual volume) and capillary blood gas analysis (most importantly pO2 in mmHG and pCO2 in mmHG). These measurements will be combined to classify patients as showing normal, restrictive, obstructive lung function impairment, as being hypoxic, hypercapnic, respectively.

    Measured: 1 year

  4. EMG

    Diaphragm and accessory respiratory muscle electromyography

    Measured: 1 year

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted27 Oct 2023
  2. Study start1 Dec 2024
  3. Primary completion1 Dec 2024
  4. Study completion1 Dec 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
25 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06105450
Sponsor's protocol ID
23-296
Acronym
RMA-COVID-19
Status last verified
Jan 2026
First submitted
26 Oct 2023
Last updated
28 Jan 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Regmi B, Friedrich J, Jorn B, Senol M, Giannoni A, Boentert M, Daher A, Dreher M, Spiesshoefer J. Diaphragm Muscle Weakness Might Explain Exertional Dyspnea 15 Months after Hospitalization for COVID-19. Am J Respir Crit Care Med. 2023 Apr 15;207(8):1012-1021. doi: 10.1164/rccm.202206-1243OC.

    PubMed 36596223

  • Spiesshoefer J, Herkenrath S, Henke C, Langenbruch L, Schneppe M, Randerath W, Young P, Brix T, Boentert M. Evaluation of Respiratory Muscle Strength and Diaphragm Ultrasound: Normative Values, Theoretical Considerations, and Practical Recommendations. Respiration. 2020;99(5):369-381. doi: 10.1159/000506016. Epub 2020 May 12.

    PubMed 32396905

  • Sudre CH, Murray B, Varsavsky T, Graham MS, Penfold RS, Bowyer RC, Pujol JC, Klaser K, Antonelli M, Canas LS, Molteni E, Modat M, Jorge Cardoso M, May A, Ganesh S, Davies R, Nguyen LH, Drew DA, Astley CM, Joshi AD, Merino J, Tsereteli N, Fall T, Gomez MF, Duncan EL, Menni C, Williams FMK, Franks PW, Chan AT, Wolf J, Ourselin S, Spector T, Steves CJ. Attributes and predictors of long COVID. Nat Med. 2021 Apr;27(4):626-631. doi: 10.1038/s41591-021-01292-y. Epub 2021 Mar 10.

    PubMed 33692530

  • Langer D, Ciavaglia C, Faisal A, Webb KA, Neder JA, Gosselink R, Dacha S, Topalovic M, Ivanova A, O'Donnell DE. Inspiratory muscle training reduces diaphragm activation and dyspnea during exercise in COPD. J Appl Physiol (1985). 2018 Aug 1;125(2):381-392. doi: 10.1152/japplphysiol.01078.2017. Epub 2018 Mar 15.

    PubMed 29543134

  • Griffin L, Cafarelli E. Resistance training: cortical, spinal, and motor unit adaptations. Can J Appl Physiol. 2005 Jun;30(3):328-40. doi: 10.1139/h05-125.

    PubMed 16129897

Questions about this trial

What is this clinical trial studying?

An observational study of Covid19 and Diaphragm Injury, run by RWTH Aachen University at 1 site in Germany.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 28 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Twitch transdiaphragmatic pressure in response to supramaximal magnetic stimulation of the phrenic nerve roots (time frame: 1 year). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06105450, which also lists 5 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Jan 2026.

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