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

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.

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.

Study Overview

• Status: Withdrawn
• Conditions: Critical Illness; ARDS; Ventilator-Induced Lung Injury
• Intervention / Treatment: 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

Contacts and Locations

Study Locations

• United Kingdom
  • London, United Kingdom, SE1 7EH
    • Guys and St Thomas NHS Foundation

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• 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.

Description

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

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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	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.	30, 60 and 120 mins

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess recruitment at the beginning and after the end of APRV ventilation in patients with moderate-severe ARDS.	To assess recruitment measuring change in end expiratory lung impedance (EELI) with EIT technique, and EELV with nitrogen wash-out/wash-in technique.	2 hours
To compare lung strain measured at APRVpre and after the end of APRV ventilation (APRVpost) in patients with moderate-severe ARDS	Strain will be calculated at time APRVpre using the strain formula (TV/EELV)	2 hours

Collaborators and Investigators

• Sponsor: Guy's and St Thomas' NHS Foundation Trust
• Investigators: Principal Investigator: Luigi Camporota, Guy's and St Thomas' NHS Foundation Trust

Study record dates

Study Major Dates

• Study Start (Anticipated): June 1, 2018
• Primary Completion (Anticipated): December 31, 2018
• Study Completion (Anticipated): December 31, 2018

Study Registration Dates

• First Submitted: May 2, 2017
• First Submitted That Met QC Criteria: May 2, 2017
• First Posted (Actual): May 4, 2017

Study Record Updates

• Last Update Posted (Actual): August 17, 2022
• Last Update Submitted That Met QC Criteria: August 15, 2022
• Last Verified: August 1, 2022

More Information

Terms related to this study

• Keywords: recruitment; lung homogeneity; airway pressure release ventilation
• Additional Relevant MeSH Terms: Pathologic Processes; Respiratory Tract Diseases; Lung Diseases; Wounds and Injuries; Disease Attributes; Thoracic Injuries; Critical Illness; Lung Injury; Ventilator-Induced Lung Injury
• Other Study ID Numbers: 123456789 (Bandirma Onyedi Eylul University)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No
• IPD Plan Description: All shared data will be as a mean and not as individual

Drug and device information, study documents

• 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