NAVA Unloading - Effects on Distribution of Ventilation

April 14, 2016 updated by: Peter Sackey, Karolinska University Hospital

Reduced Unloading in NAVA Improves Distribution of Ventilation in ICU Patients

Title: Reduced Unloading in NAVA Improves distribution of Ventilation in ICU patients.

Objectives:

  1. To investigate if NAVA targeted to moderate respiratory muscular unloading results in redistribution of ventilation to the dorsal regions of the lungs
  2. To verify if the redistribution of ventilation translates to a better gas exchange and to a potentially lung protective ventilation strategy (lower airway pressures)
  3. To verify the possibility to set NAVA at different levels of unloading, based on Neuro-Ventilatory Efficiency.

Study Design: Randomised Crossover of Pressure Support and NAVA at different levels of unloading.

Population: Adult Intubated patients at the Neurosurgical ICU, ventilated for more than 48h, in weaning phase from mechanical ventilation.

Study duration: 2,5h Number of subjects: 12

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Detailed Description

Critically ill patients on mechanical ventilation are at risk for developing respiratory muscle atrophy. Partial Assist modes such Pressure Support (PS) and Neurally Adjusted Ventilatory Assist (NAVA) are developed to maintain patients´own effort in breathing. However there are no recommendations on how to set the optimal ventilator support in NAVA to avoid over- or underassistance.

A previous Electrical Impedance Thomography (EIT) study has shown a redistribution of ventilation towards the dorsal regions of the lung in acute lung injury patients ventilated with NAVA, compared to PS.

In the present study, the assist is targeted to different respiratory muscle unloading, predefined and based on the Neuro-Ventilatory Efficiency (NVE). The NVE will be measured at 10min intervals and NAVA level adjusted if needed, to keep constant the level of unloading in each study step.

Protocol: Once enrolled, the patients are ventilated in PS (PScli1) as set by the clinician. They are then ventilated in NAVA at 3 different levels of muscle unloading in randomized order. At NAVAcli, the assist level matches to PScli1 in terms of muscle unloading. With NAVA40% and NAVA60%, the patients have 40% and 60% unloading, respectively. In the last study step the patients are back to PS (PScli2). Each patient is his/her own control and goes through the 5 ventilation periods, of 30min each. In the last 5 min of each study step, the CoV (obtained through the EIT data), blood gas samples (for oxygenation and ventilation) and ventilatory parameters are obtained and analyzed.

The investigators hypothesize that

  1. It is possible to set NAVA at different levels of unloading, based on NVE.
  2. Moderate muscle unloading (corresponding to NAVA40%) keeps the diaphragm active and thereby leads to more dorsal distribution of ventilation compared to PScli and to higher unloading in NAVA.
  3. Secondarily and as a consequence of the redistribution of ventilation, we hypothesize that the gas exchange will remain unchanged or will improve and that the airway pressures will decrease for moderate unloading (NAVA40%).

Study Type

Interventional

Enrollment (Anticipated)

12

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Patients belonging to Neurosurgical ICU
  • Intubated for ≥48h
  • Weaning phase from Mechanical Ventilation

Exclusion Criteria:

  • bleeding disorders (PK INR>1,5 or APTT>50s or platelet count <50000/µL) or
  • unstable intracranial pressure (ICP>20 mmHg during the latest 8 hours) or
  • unstable circulation (requiring high vasopressor dose, for example Noradrenalin >0,2µg/kg/min) or
  • too severe lung disease (PFI ≤ 26,7 kPa or PEEP >10 cmH2O or FiO2>0,5 at study entry point) or
  • fever> 38,5°C or
  • tendency to hyperventilation (PaCO2 < 4,5 kPa at study entry point).

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: PScli1
Patients are ventilated in Pressure support (PS) according to the Clinical settings for 30min.
Device: PScli1
Pressure support set by clinicians prior to inclusion
Other Names:
  • Pressure support
Active Comparator: NAVAcli
Patients are ventilated in Neurally Adjusted Ventilatory Assist (NAVA) and the assist is set in order to match to respiratory muscle unloading reached with PScli1. Patients are ventilated in NAVAcli for 30min.
Device: Neurally adjusted ventilatory assist

Ventilation supported by NAVA

  • Blood gas analysis
  • Respiratory Parameters At the end of the study step Neuro-Ventilatory Efficiency and Neuro-Mechanical Efficiency are measured.
Other Names:
  • NAVA
Active Comparator: NAVA40%
Patients are ventilated in Neurally Adjusted Ventilatory Assist (NAVA) and the assist is set in order to target 40% muscle unloading based on the Neuro-Ventilatory Efficiency (NVE) measurement. Patients are ventilated in NAVA40% for 30min.
Device: Neurally adjusted ventilatory assist

Ventilation supported by NAVA

  • Blood gas analysis
  • Respiratory Parameters At the end of the study step Neuro-Ventilatory Efficiency and Neuro-Mechanical Efficiency are measured.
Other Names:
  • NAVA
Active Comparator: NAVA60%
Patients are ventilated in Neurally Adjusted Ventilatory Assist (NAVA) and the assist is set in order to target 60% muscle unloading based on the Neuro-Ventilatory Efficiency (NVE) measurement. Patients are ventilated in NAVA60% for 30min.
Device: Neurally adjusted ventilatory assist

Ventilation supported by NAVA

  • Blood gas analysis
  • Respiratory Parameters At the end of the study step Neuro-Ventilatory Efficiency and Neuro-Mechanical Efficiency are measured.
Other Names:
  • NAVA
Active Comparator: PScli2
Patients return to PS ventilation, according to the Clinical settings as in PScli1 for 30min.
Device: PScli2
Pressure support at the same level as prior to the study
Other Names:
  • Pressure support

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Center of Ventilation (CoV), expressed in percent (ventral to dorsal)
Time Frame: Total study time is 2,5 hours
The distribution of ventilation is summarized by the CoV, a parameter obtained by the EIT monitor. Recordings are made at the end of each study step (total 5), lasting 30min.
Total study time is 2,5 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Gas Exchange (PaO2 and PaCO2)
Time Frame: During the last 5min of each study step (each 30min), total 5 steps. Total study time 2,5 hours
Comparison between study steps
During the last 5min of each study step (each 30min), total 5 steps. Total study time 2,5 hours
Airway Pressure
Time Frame: 2,5 hours
2,5 hours
Muscle unloading based on Neuro-Ventilatory Efficiency and Neuro-Mechanica Efficiency
Time Frame: 2,5 hours
2,5 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Karolinska University Hospital

Investigators

  • Study Chair: Peter V Sackey, MD, PhD, Karolinska University Hospital
  • Principal Investigator: Francesca Campoccia Jalde, MD, Karolinska University Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2015

Primary Completion (Anticipated)

September 1, 2016

Study Completion (Anticipated)

September 1, 2016

Study Registration Dates

First Submitted

March 14, 2016

First Submitted That Met QC Criteria

March 16, 2016

First Posted (Estimate)

March 17, 2016

Study Record Updates

Last Update Posted (Estimate)

April 15, 2016

Last Update Submitted That Met QC Criteria

April 14, 2016

Last Verified

April 1, 2016

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2015/521-31/4

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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