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Supported Ventilation in ARDS Patients

Not Applicable
Completed
Conditions
Tidal Volume
Mechanical Ventilation
Acute Respiratory Distress Syndrome
Interventions
Registration Number
NCT02064140
Lead Sponsor
University Medical Center Nijmegen
Brief Summary

Acute respiratory distress syndrome (ARDS) is characterized by acute bilateral pulmonary infiltrates and impairment of oxygen uptake. For example, pneumonia can cause the development of ARDS. Despite modern intensive care treatment, mortality in ARDS patients remains high (40%). Invasive mechanical ventilation (MV) is the mainstay of ARDS treatment. Controlled MV is the conventional ventilation strategy to ensure lung protective ventilation (low tidal volumes) and recovery of the lungs. However, among disadvantages of controlled MV are the development of respiratory muscle atrophy (due to disuse) and the need for high dose sedatives to prevent patient-ventilator asynchrony. The use of high doses of sedatives and respiratory muscle weakness are associated with increased morbidity, worse clinical outcomes and prolonged MV.

Besides controlled MV, a patient can be ventilated with supported ventilation. Supported MV decreases the likelihood to develop muscle atrophy, improves oxygenation and hemodynamics, and lowers consumption of sedatives. However potential disadvantages of supported ventilation include generation of too high tidal volumes, especially in patients with high respiratory drive. A previous study in healthy subjects has shown that titration of neuromuscular blocking agent (NMBA) can decrease activity of inspiratory muscles, while maintaining adequate ventilation. It is hypothesized that low dose NMBA may enable supported MV with adequate tidal volumes, in patients with high respiratory drive.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
12
Inclusion Criteria
  • age > 18 year
  • informed consent
  • ARDS according to the Berlin definition
  • RASS -4/-5
  • tidal volume > 8 ml/kg during supported ventilation
  • double balloon esophageal EMG NAVA catheter
Exclusion Criteria
  • recent use of muscle relaxants / NMBAs (< 3 hours)
  • pre-existent neuromuscular disease (congenital or acquired) or diseases / disorders know to be associated with myopathy including auto-immune diseases
  • phrenic nerve lesions
  • elevated intracranial pressure or clinical suspicion of elevated intracranial pressure (i.e. neurotrauma)
  • open chest or abdomen
  • pregnancy
  • systolic blood pressure < 90 mm Hg / MAP < 65 mm Hg

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Neuromuscular blocking agentRocuronium-
Primary Outcome Measures
NameTimeMethod
Feasibility of titrating tidal volume < 6 ml/kgWithin 5 minutes after titration of NMBA

The feasibility of titrating tidal volume in ARDS patients below 6 ml/kg using NMBA is evaluated in every patient. The outcome measure is dichotomic (yes/no).

Secondary Outcome Measures
NameTimeMethod
Respiratory rateArtefact-free period in the first 15 minutes during different ventilatory modes after titration of NMBA

A secondary outcome measure is the respiratory rate after titration NMBA during different ventilatory modes.

Diaphragm electrical activityArtefact-free period in the first 15 minutes during different ventilatory modes after titration of NMBA.

A secondary outcome measure is the root-mean-square of the diaphragm electrical activity after titration NMBA during different ventilatory modes.

Transpulmonary pressureArtefact-free period in the first 15 minutes during different ventilatory modes after titration of NMBA.

Transpulmonary pressure is determined as the difference between mouth pressure and esophageal pressure during inspiration. Breath-by-breath data are ensemble-averaged over the first 2 minutes after titration NMBA during different ventilatory modes.

Transdiaphragmatic pressureArtefact-free period in the first 15 minutes during different ventilatory modes after titration of NMBA.

Transdiaphragmatic pressure is determined as the difference between gastric pressure and esophageal pressure during inspiration. Breath-by-breath data are ensemble-averaged over the first two minutes after titration NMBA during different ventilatory modes.

Neuroventilatory efficiencyArtefact-free period in the first 15 minutes during different ventilatory modes after titration of NMBA.

A secondary outcome measure is the neuroventilatory efficiency (i.e. the ratio of diaphragm electrical activity and tidal volume) after titration NMBA during different ventilatory modes.

Neuromechanical efficiencyArtefact-free period in the first 15 minutes during different ventilatory modes after titration of NMBA.

A secondary outcome measure is the neuromechanical efficiency (i.e. the ratio of diaphragm electrical activity and transdiaphragmatic pressure) of the diaphragm after titration NMBA during different ventilatory modes.

Patient-ventilator contribution to breathingDuring titration of NMBA (each three minutes) and during PS and NAVA after titration NMBA

A secondary outcome measure is the patient-ventilator contribution to breathing (i.e. ratio of: the ratio of tidal volume and diaphragm electrical activity without assist, and the ratio of tidal volume and diaphragm electrical acticity with assist) during and after titration of NMBA.

Oxygenation indexBefore start of the study; before titration of NMBA during different ventilatory modes; after titration of NMBA; after an hour for each ventilatory mode.

A secondary parameter is the oxygenation index which is determined as the ratio between arterial oxygen tension and fraction of inspired oxygen.

Carbon dioxide tension in arterial blood (PaCO2)Before start of the study; before titration of NMBA during different ventilatory modes; after titration of NMBA; after an hour for each ventilatory mode.

A secondary parameter is the carbon dioxide tension in arterial blood.

pH of arterial bloodBefore start of the study; before titration of NMBA during different ventilatory modes; after titration of NMBA; after an hour for each ventilatory mode.

A secondary parameter is the pH of arterial blood.

Patient-ventilator interactionArtefact-free period in the first 15 minutes during different ventilatory modes after titration of NMBA.

Patient-ventilator interaction is evaluated using the NeuroSync index during different ventilatory modes.

Trial Locations

Locations (1)

Radboud university medical center

🇳🇱

Nijmegen, Netherlands

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