Effect of PEEP on Lung Recruitment and Homogeneity Over Time in Moderate to Severe ARDS (APRV)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT03140579
Recruitment Status : Not yet recruiting
First Posted : May 4, 2017
Last Update Posted : January 5, 2018
Information provided by (Responsible Party):
Guy's and St Thomas' NHS Foundation Trust

Brief Summary:

This study evaluates the effect of airway pressure release ventilation (APRV) on lung homogeneity and recruitment in patients with moderate to severe acute respiratory distress syndrome (ARDS).

It will do this by comparing the homogeneity of ventilation and recruitment prior to a patient being ventilated on APRV, and at 30, 60 and 120 minutes after starting APRV.

Condition or disease Intervention/treatment
ARDS Critical Illness Ventilator-Induced Lung Injury Other: APRV

Detailed Description:

Ventilator-induced lung injury (VILI) is a well-recognised problem of ventilation in patients with ARDS, and is currently treated with lung-protective ventilation, which limits tidal volumes and airway pressures by applying higher levels of positive-end expiratory pressure (PEEP). However, it is not known whether higher levels of PEEP increases recruitment and homogeneity of ventilation within the lungs.

APRV is a mode of inverse ventilation, where high levels of PEEP are maintained with brief releases of pressure, and has been proposed as an appropriate method of ventilation in patients with ARDS.

This study will assess homogeneity of ventilation and recruitment in 15 patients before APRV is started, and 30, 60 and 120 mins after commencing APRV. It will do this using Electrical Impedance Tomography (EIT), nitrogen wash in/wash out technique, and lung strain.

Study Type : Observational
Estimated Enrollment : 15 participants
Observational Model: Cohort
Time Perspective: Prospective
Official Title: Estimation of Long Term PEEP Effect on Lung Homogeneity and Recruitment Using APRV Ventilation:Measurement of End Expiratory Lung Volume With Nitrogen Wash-out/wash-in Technique and End Expiratory Lung Impedance With EIT at Different Times.
Estimated Study Start Date : June 1, 2018
Estimated Primary Completion Date : December 31, 2018
Estimated Study Completion Date : December 31, 2018

Intervention Details:
  • Other: APRV
    Airway pressure release ventilation is a method of inverse ventilation, where high levels of positive end expiratory pressure are maintained to optimise oxygenation with brief releases of pressure to allow ventilation and release carbon dioxide. It is an approved and frequently used method of ventilation.

Primary Outcome Measures :
  1. To compare lung homogeneity estimated with EIT upon commencing APRV (APRVpre) and after 30 - 60 - 120 min of APRV ventilation (APRV30, APRV60, APRV120) in patients with moderate to severe ARDS [ Time Frame: 30, 60 and 120 mins ]
    EIT will be measured at time APRVpre during a "low-flow maneuver" consisting of a brief switch to PC ventilation: with a flow of 4 L/min, airway pressure will be gradually increased up to 30 cmH20 in order to see how the lung changes elastically minimising resistance. EIT will also be measured after 30 min (time APRV30), 60 min (time APRV60), 120 min (time APRV120) since APRV has started.

Secondary Outcome Measures :
  1. To assess recruitment at the beginning and after the end of APRV ventilation in patients with moderate-severe ARDS. [ Time Frame: 2 hours ]
    To assess recruitment measuring change in end expiratory lung impedance (EELI) with EIT technique, and EELV with nitrogen wash-out/wash-in technique.

  2. To compare lung strain measured at APRVpre and after the end of APRV ventilation (APRVpost) in patients with moderate-severe ARDS [ Time Frame: 2 hours ]
    Strain will be calculated at time APRVpre using the strain formula (TV/EELV)

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 80 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
All Patients admitted to ICU ventilated with moderate or severe ARDS, based on the Berlin definition of ARDS.

Inclusion Criteria:

  • Age ≥ 18 years and < 80 years

    • Weight > 35 Kg and BMI < 40
    • Informed consent according to local regulations
    • Hemoglobin ≥ 70 g/dl
    • Haemodynamically stable > 4 hours
    • Moderate to severe ARDS (PaO2/FIO2 < 26.6 kPa with positive end-expiratory pressure (PEEP) > 5 cmH2O) as per Berlin definition of ARDS

Exclusion Criteria:

  • Expected survival < 72 hours

    • Suspected pregnancy (negative pregnancy test required for women of child-bearing potential)
    • Open abdomen
    • Documented or suspected raised intracranial pressure
    • Active air leak (pneumothorax, pneumomediastinum, subcutaneous emphysema)
    • Morbid obesity BMI > 40
    • Recent < 1 week cardiac or thoracic surgery
    • Unstable thorax and sternum with paradoxical chest wall movement
    • Severe Chronic Respiratory Disease (COPD) - GOLD 3 or 4 emphysema with bullae
    • Severe smoking (> 40 pack-year history)
    • Liver Failure: Child-Pugh Class C
    • Massive ascites
    • Lung fibrosis
    • Severe cardiac disease (one of the following): New York Heart Association Class III or IV, acute coronary syndrome or persistent ventricular tachyarrhythmias
    • Sickle cell disease

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT03140579

Contact: Gill Arbane 02071887188 ext 88070
Contact: Luigi Camporota 02071887188

United Kingdom
Guys and St Thomas NHS Foundation Not yet recruiting
London, United Kingdom, SE1 7EH
Contact: Gill Arbane    02071887070   
Sponsors and Collaborators
Guy's and St Thomas' NHS Foundation Trust
Principal Investigator: Luigi Camporota Guy's and St Thomas' NHS Foundation Trust

Responsible Party: Guy's and St Thomas' NHS Foundation Trust Identifier: NCT03140579     History of Changes
Other Study ID Numbers: 123456789
First Posted: May 4, 2017    Key Record Dates
Last Update Posted: January 5, 2018
Last Verified: January 2018
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Plan Description: All shared data will be as a mean and not as individual

Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No

Keywords provided by Guy's and St Thomas' NHS Foundation Trust:
lung homogeneity
airway pressure release ventilation

Additional relevant MeSH terms:
Critical Illness
Lung Injury
Ventilator-Induced Lung Injury
Disease Attributes
Pathologic Processes
Lung Diseases
Respiratory Tract Diseases
Thoracic Injuries
Wounds and Injuries