Mechanical Ventilation and Respiratory Muscle Work of Breathing in Acute Respiratory Distress Syndrome (ARDS) Patients

Not Applicable

Completed

• Conditions: ARDS
• Interventions: Device: Mechanical ventilation

• Registration Number: NCT01289600
• Lead Sponsor: University Medical Center Nijmegen

Brief Summary

The purpose of this study is to demonstrate that mechanical ventilation guided by the diaphragm EMG signal (also know as neurally adjusted ventilatory assist \[NAVA\]) is superior compared to pressure support and pressure control ventilation.

Detailed Description

Not available

Study Timeline

• Study Start: 2011-01
• Study First Submitted: 2011-01-27
• Study First Submitted QC: 2011-02-02
• Study First Posted: 2011-02-04
• Primary Completion: 2013-03
• Study Completion: 2013-03
• Status Verified: 2015-06
• Last Update Submitted: 2015-06-09
• Last Update Posted: 2015-06-10

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 12

Inclusion Criteria

• intubated, mechanically ventilated patients
• meeting criteria for ARDS
• mean arterial blood pressure > 65 mmHg (with or w/o vasopressors)

Exclusion Criteria

• pregnancy
• increased intracranial pressure
• contra-indication naso-gastric tube
• diagnosed neuro-muscular disorder
• recent (<12 hours) use of muscle relaxants
• exclusion from sedation interruption protocol as used in our institution
• open chest or- abdomen
• very high inspiratory flow rate during supported ventilation
• inability to obtain informed consent

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Neurally adjusted ventilatory assist, titrated	Mechanical ventilation	Mechanical ventilator is set to NAVA for 30 min with PEEP titrated using the diaphragm EMG signal.
Neurally adjusted ventilatory assist, ARDSnet	Mechanical ventilation	Mechanical ventilator is set to NAVA for 30 min with PEEP set according to the "higher arm" of the ARDS network consensus.
Pressure support ventilation, ARDSnet	Mechanical ventilation	Mechanical ventilator is set to pressure support ventilation (6 ml/kg) for 30 min with positive end expiratory pressure (PEEP) set according to the "higher arm" of the ARDS network consensus.
Pressure control ventilation, ARDSnet	Mechanical ventilation	Mechanical ventilator is set to pressure control ventilation (6 ml/kg) for 30 min with PEEP set according to the "higher arm" of the ARDS network consensus.

Primary Outcome Measures

Name	Time	Method
Pressure-time product of the diaphragm	average of last 15 minutes of each study arm	The pressure-time product of the transdiaphragmatic pressure (Pdi) during inspiration is obtained for each breath by multiplying the corresponding mean inspiratory Pdi signal above the end-expiratory baseline by the inspiration time. Breath-by-breath data are ensemble-averaged over the last 15 minutes of each study arm.
Patient - ventilator asynchrony index	average of last 15 minutes of each study arm	Ventilator asynchrony is determined as the sum of the triggering and cycling-off delays per breath, expressed as a percentage of the total breath duration. The trigger delay is measured as the time difference between the onset of neural inspiration and the ventilator inspiratory flow, and the cycling delay as the time difference between the end of neural inspiration and the end of ventilator inspiratory flow. Breath-by-breath data are ensemble-averaged over the last 15 minutes of each study arm.

Secondary Outcome Measures

Name	Time	Method
Transpulmonary pressure	average of last 15 minutes of each study arm	Transpulmonary pressure is determined as the difference between mouth pressure and esophageal pressure during inspiration. Breath-by-breath data are ensemble-averaged over the last 15 minutes of each study arm.
Transdiaphragmatic pressure	average of last 15 minutes of each study arm	Transdiaphragmatic pressure is determined as the difference between gastric pressure and esophageal pressure during inspiration. Breath-by-breath data are ensemble-averaged over the last 15 minutes of each study arm.
Oxygenation index	at the end of each study arm	Oxygenation index is determined as the ratio between arterial oxygen tension and fraction of inspired oxygen. Arterial oxygen tension is obtained at the end of each study arm.
Dead space ventilation	average of last 15 minutes of each study arm	Dead space ventilation is determined each breath using the Bohr equation: (PaCO2-PeCO2/PaCO2)\*Vt. Here Vt is tidal volume, PaCO2 is the partial pressure of carbon dioxide in the arterial blood, and PeCO2 is the end-tidal carbon dioxide tension in the expired air. Breath-by-breath data are ensemble-averaged over the last 15 minutes of each study arm.

Trial Locations

Locations (1)

University Medical Center Nijmegen; 🇳🇱 Nijmegen, Gelderland, Netherlands