Diaphragm Electromyography to Estimate Breathing Effort: a Physiological Study
Overview
- Phase
- Not Applicable
- Intervention
- Not specified
- Conditions
- Diaphragm Injury
- Sponsor
- Amsterdam UMC, location VUmc
- Enrollment
- 17
- Locations
- 1
- Primary Endpoint
- Transdiaphragmatic pressure
- Status
- Completed
- Last Updated
- 5 years ago
Overview
Brief Summary
Mechanical ventilation may be necessary to save the life of a patient due to an accident, pneumonia or surgery. The ventilator then temporarily takes over the function of the respiratory muscles. During treatment in the Intensive Care, the amount of support provided by the ventilator is usually lowered gradually, until the point that the patient can breathe unassisted once again. However, in a large fraction of patients (up to 40%) it takes days to weeks before the patient is able to breathe unassisted, even after the initial disease has been treated. This is called prolonged weaning.
A possible cause of prolonged weaning is weakness of the respiratory muscles. The diaphragm, the largest respiratory muscle, can become weakened if it is used too little, much like all other muscles in the body. Additionally, damage and weakness of the diaphragm can occur when the diaphragm has to work excessively. Therefore, it is important that the diaphragm works enough; not so little that it becomes weakened, but not too much either.
Measurements of pressure generated by the diaphragm are needed to determine the current level of diaphragm activity in a patient on mechanical ventilation. However, these measurements are rarely performed, because they are time-consuming and require placement of two additional nasogastric catheters. This is a shame, as adequate loading of the diaphragm might prevent development of weakness, leading to shorter duration of mechanical ventilation. Finding alternative measurements of diaphragm effort might be a solution to this problem.
It has been hypothesized that the electrical activity of the diaphragm provides a reliable indication of diaphragm effort. This study aims to determine whether there is a correlation between pressure generation by the diaphragm and electrical activity of the diaphragm over a wide range of respiratory activity, from low effort to extreme effort, in healthy volunteers.
Investigators
Prof.dr. L.M.A. Heunks
Clinical professor
Amsterdam UMC, location VUmc
Eligibility Criteria
Inclusion Criteria
- •Informed Consent
- •Age \>18 years
Exclusion Criteria
- •History of cardiac and/or pulmonary disease or current medication use
- •History of pneumothorax
- •Contra-indications for nasogastric tube placement (recent epistaxis, severe coagulopathy, current upper airway pathology)
- •Contra-indication for magnetic stimulation (cardiac pacemakers or metal in cervical area)
Outcomes
Primary Outcomes
Transdiaphragmatic pressure
Time Frame: Transdiaphragmatic pressure will be assessed at multiple levels of breathing effort in each subject for two hours.
The pressure gradient over the diaphragm will be obtained by subtracting the esophageal pressure from the pressure in the stomach, measured with specialized catheters, and will be reported in centimeters of water (cmH2O) as described in ref 3, American Thoracic Society (ATS) statement on respiratory muscle testing.
Electrical activity of the diaphragm
Time Frame: Electrical activity of the diaphragm will be assessed at multiple levels of breathing effort in each subject for two hours.
Diaphragm electromyography will be obtained with multiple electrode pairs situated on specialized esophageal catheters. The raw diaphragm electromyography will be filtered and integrated to obtain the compound mean action potential reported in microvolts (μV) as described in ref 1 (Sinderby et al.).
Secondary Outcomes
- Work of breathing(Work of breathing will be assessed at multiple levels of breathing effort in each subject for two hours.)
- Pressure-time product of the respiratory muscles(Pressure-time product of the respiratory muscles will be assessed at multiple levels of breathing effort in each subject for two hours.)
- Mechanical power(Mechanical power will be assessed at multiple levels of breathing effort in each subject for two hours.)
- Pressure-time product of the diaphragm(Pressure-time product of the diaphragm will be assessed at multiple levels of breathing effort in each subject for two hours.)