Electromyography for Diaphragm Effort

Not Applicable

Completed

• Conditions: Muscle Weakness; Physiological Stress; Diaphragm Injury; Weaning Failure
• Interventions: Other: Inspiratory threshold loading protocol

• Registration Number: NCT03580720
• Lead Sponsor: Amsterdam UMC, location VUmc

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2018-05-16
• Study First Submitted: 2018-06-08
• Study First Submitted QC: 2018-06-25
• Study First Posted: 2018-07-09
• Primary Completion: 2019-04-15
• Study Completion: 2019-04-30
• Status Verified: 2020-05
• Last Update Submitted: 2020-05-19
• Last Update Posted: 2020-05-20

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 17

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)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Intervention	Inspiratory threshold loading protocol	Intervention group, receiving Inspiratory threshold loading protocol.

Primary Outcome Measures

Name	Time	Method
Transdiaphragmatic pressure	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	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 Outcome Measures

Name	Time	Method
Work of breathing	Work of breathing will be assessed at multiple levels of breathing effort in each subject for two hours.	Work of breathing will be obtained by integrating the pressure-volume loops of esophageal pressure and tidal volume, and will be reported in Joule per minute as described in ref 3, ATS statement on respiratory muscle testing..
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.	Pressure-time product of the respiratory muscles will be obtained by dividing the time-integral of esophageal pressure over time, and will be reported as cmH20\*s per minute as described in ref 3, ATS statement on respiratory muscle testing..
Mechanical power	Mechanical power will be assessed at multiple levels of breathing effort in each subject for two hours.	Mechanical power will be obtained by multiplying the work of breathing (described above) by the number of breaths per minute, and will be reported in Watt (joule/minute) as described in ref 3, ATS statement on respiratory muscle testing..
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.	Pressure-time product of the diaphragm will be obtained by dividing the time-integral of transdiaphragmatic pressure (described above) over time, and will be reported as cmH20\*s per minute as described in ref 3, ATS statement on respiratory muscle testing..

Trial Locations

Locations (1)

Amsterdam UMC, location VUmc; 🇳🇱 Amsterdam, Noord-Holland, Netherlands