Fatigue and exercise intolerance after survived COVID-19-infection might be related to weakness of the respiratory muscles especially following invasive mechanical ventilation in the Intensive Care Unit. The aim of the project is to measure respiratory muscle function and strength in our respiratory physiology laboratory (Respiratory Physiology Laboratory, Department of Pneumology and Intensive Care Medicine, Head: Professor Michael Dreher) in patients who survived a severe COVID-19-infection (25 with a severe course requiring mechanical ventilation in the intensive care unit, 25 with a moderate-severe course requiring administration of supplemental oxygen only, respectively). Based on this data the aim is to develop a model which determines the severity, pathophysiology and clinical consequences of respiratory muscle dysfunction in patients who had been hospitalised for COVID-19. This will potentially prove the importance of a dedicated pulmonologic rehabilitation with respiratory muscle strength training in patients who had been hospitalised for COVID-19.
The aim of the present project is to comprehensively measure respiratory muscle function and strength in patients who survived a hospitalisation for a severe COVID-19-infection (25 with a severe course requiring mechanical ventilation in the intensive care unit, 25 with a moderate-severe course requiring administration of supplemental oxygen only, respectively). We intend to recruit 50 patients during their regular follow up appointments (12 months and 24 months after their discharge from the hospital) in our pulmonology outpatient-clinic. Patients fulfilling the criterions of inclusion and exclusion will be included. Patients will undergo a series of measurements on one day in our respiratory physiology laboratory (Respiratory Physiology Laboratory, Department of Pneumology and Intensive Care Medicine, Head: Professor Michael Dreher). Patients will be asked to complete a questionnaire, followed by some examinations comprising spirometry by bodyplethysmography, exercise endurance, capillary blood gas analyses, measurement of maximum inspiratory and expiratory mouth pressures, dynamometric measurement of arm and leg strength, diaphragm ultrasound, magnetic stimulation of the phrenic and lower thoracic nerves with invasive recording of twitch transdiaphragmatic pressure and markers of systemic inflammation based on in depth analyses of blood samples that will be obtained. Based on this data the aim is to develop a model which determines the severity, pathophysiology and clinical consequences of respiratory muscle dysfunction in patients who had been hospitalised for COVID-19. This will potentially prove the importance of a dedicated pulmonologic rehabilitation with respiratory muscle strength training in patients who had been hospitalised for COVID-19.
Study Type
OBSERVATIONAL
Enrollment
50
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.
Jens Spiesshoefer
Aachen, North Rhine-Westphalia, Germany
Twitch transdiaphragmatic pressure in response to supramaximal magnetic stimulation of the phrenic nerve roots
Recording of twitch transdiaphragmatic pressure (Unit: Pressure in cmH2O)
Time frame: 2 years
Respiratory mouth pressures
Measurement of respiratory (inspiratory and expiratory) mouth pressures (Unit: Pressure in cmH2O)
Time frame: 2 years
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.
Time frame: 2 years
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.
Time frame: 2 years
Analyses of markers of systemic inflammation (interleukin levels in ng/ml, TNF alpha in ng/ml, CRP in mg/L; immune phenotyping of inflammatory cells, most importantly whilte blood cell subtypes in %)
Analyses of markers of systemic inflammation based on blood samples taken. These measurements will be combined to classify patients as having increased or normal levels of systemic inflammation.
Time frame: 2 years
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.
Time frame: 2 years
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