General Anaesthesia, Muscle Weakness
Conditions
Keywords
VIDD, ICUAW, muscle weakness
Brief summary
Ventilator-induced diaphragmatic dysfunction is a common issue in critically ill patients. Muscle stimulation has shown to have beneficial effects in muscle groups on the extremities. A non-invasive way to stimulate the diaphragm would be the electromagnetic stimulation but it is currently unclear if that is feasible. In this proof-of-concept trial the primary aim is to show that it is possible to induce a diaphragmatic contraction leading to an inspiration with a sufficient tidal volume via an external electromagnetic stimulation of the phrenic nerve in obese patients.
Detailed description
During the time of first spontaneous breathing trial 60% of mechanically ventilated patients present with diaphragmatic weakness or also know as ventilator-induced diaphragmatic dysfunction (VIDD). The damage to the diaphragm in terms of muscle atrophy has been shown as early as 12 hours after initiation of mechanical ventilation. Recently, a correlation between diaphragmatic atrophy and mortality could be established. Induction of diaphragmatic contractions via stimulation of the phrenic nerve would be a possible method to prevent or treat VIDD. A possible modality would be the non-invasive electromagnetic stimulation but feasibility has not been established. In this proof-of-concept trial the primary aim is to show that it is possible to induce a diaphragmatic contraction leading to an inspiration with a sufficient tidal volume via an external electromagnetic stimulation of the phrenic nerve in obese patients
Interventions
Electromagnetic stimulation of the phrenic nerve
Sponsors
Study design
Eligibility
Inclusion criteria
* ≥ 18 years of age * American Society of Anaesthesiologists Classification I or II * Planned anesthesia with intubation * Adipositas Grade II-III
Exclusion criteria
* Chronic lung disease * Preexisting diaphragmatic weakness * Neurologic disease with known motor weakness * Paralysis of the phrenic nerve * Contraindication for any movement in the cervical vertebrae * Conditions that limit the movement of the diaphragm e.g. ascites, increased intraabdominal pressure. * Inability to communicate in the official language * Infections, lesions or stricture in the neck area * Implanted cardiac devices e.g. pace maker, defibrillator, event recorder * Implanted medical pumps e.g. left ventricular assist device * Metal implants in the upper body * Preganancy
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 1.Tidal volume generated by electromagentical stimulation of the phrenic nerve (ml) | approximately 15 minutes | Mean tidal volume of 10 consecutively stimulations of the phrenic nerve |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Abdominal extension maximum | approximately 15 minutes | Extension of the abdomen in centimeter measured via abdominal belt |
| Air pressure during each breath | approximately 15 minutes | Change in pressure in the duct from expiration to inspiration (mbar) |
| Diaphragmatic thickening fraction | approximately 15 minutes | Diaphragmatic contractility measured by ultrasound after N. phrenicus stimulation |
| Feedback/Stimulation locus relation | approximately 15 minutes | When the stimulation locus is changed according to protocol the change of the triggered tidal volume is measured in % to the original location |
| Latency between stimulation and feedback | approximately 15 minutes | Time between start and end of the stimulation in seconds |
| Max inspiratory flow after stimulation | approximately 15 minutes | The maximal air flow created in the duct following stimulation of the N. phrenicus (meter / second) |
| Time to find the optimal stimulation point of the N. phrenicus | approximately 15 minutes | Time between first successful N. phrenicus stimulation and identification of the optimal stimulation locus in seconds |
| Distance between anatomical landmarks and optimal stimulation locus | approximately 15 minutes | Distance between anatomical landmarks and optimal stimulation locus |
| Reproducibility of stimulation answer | approximately 15 minutes | Variation of stimulated tidal volumes and diaphragm contraction using mean and standard deviation of each stimulation intensity |
| Incidence of Adverse Events during stimulation | approximately 15 minutes | Adverse Events elicited by the electromagnetic stimulation |
| Intensity/Contractility relation | approximately 15 minutes | Correlation between the simulation intensity and the diaphragmatic contractility |
Countries
Germany