The Impact of PEEP-guided Electrical Impedance Tomography on Oxygenation and Pulmonary Mechanics in Moderate-to-severe ARDS (PEEP)

Acute respiratory distress syndrome (ARDS) in its moderate to severe forms is associated with high mortality. Mechanical ventilation (MV) remains the cornerstone of ARDS management but carries a significant risk of ventilator-induced lung injury (VILI). Positive end-expiratory pressure (PEEP), a fundamental component of MV, is widely utilized in clinical practice; however, optimal PEEP selection for patients with moderate to severe ARDS remains a complex and unresolved challenge. Electrical impedance tomography (EIT), a bedside imaging modality that evaluates regional ventilation distribution, offers a means of individualizing PEEP settings in mechanically ventilated patients. By balancing the competing risks of alveolar overdistension and collapse, EIT facilitates precision in PEEP titration. This study compares the impact of EIT-guided PEEP selection versus the conventional low FiO2-PEEP table on blood oxygenation and pulmonary mechanics.

Study Overview

• Status: Recruiting
• Conditions: Mechanical Ventilation; Positive End-Expiratory Pressure; Electrical Impedance Tomography (EIT); Acute Respiratory Syndrome Distress
• Intervention / Treatment: Device: electrical impedance tomography; Other: Non-EIT

Detailed Description

This is a prospective, single-center, randomized controlled trial designed to evaluate the effects of PEEP settings guided by electrical impedance tomography (EIT) on clinical outcomes in patients with moderate to severe ARDS undergoing lung-protective ventilation. Adult intubated patients with moderate to severe ARDS will be enrolled in the study.

Patients in the intervention group will receive PEEP titrated using EIT with a stepwise decremental PEEP trial, while those in the control group will have PEEP set based on the FiO2-PEEP table. Other ventilator parameters will be managed according to the ARDSnet protocol.

The primary outcomes are blood oxygenation and pulmonary mechanics. Secondary outcomes include 28-day mortality, ventilator-free and shock-free days at 28 days, length of ICU and hospital stay, rate of successful weaning, the proportion requiring rescue therapies, complications, respiratory variables, and the Sequential Organ Failure Assessment (SOFA) score.

Before initiating recruitment maneuver, all patients were placed on mechanical ventilation set according to the ARDS network strategy for 10 minutes, ensuring SpO2 of 88-95%, PaO2 of 55-80 mmHg, and a mean arterial pressure (MAP) ≥ 65 mmHg.

• Patients received sedation and neuromuscular blockade to achieve full synchronization with the ventilator (RASS ≤ -3).
• The mode was set to Pressure-Controlled Ventilation (PCV): ΔP = 15 cmH2O, which was maintained constant during the recruitment maneuver, while FiO2, PEEP, and respiratory rate were kept as previously set.
• PEEP was incrementally increased by 5 cmH2O every minute: from 10 to 15, to 20, and finally to 25 cmH2O, with a maximum pressure limit of 40 cmH2O.
• Following the recruitment maneuver at the final PEEP level, the process of identifying the optimal PEEP was initiated.
• Then, PEEP will be set to 20 cmH2O and gradually decreased by 2 cmH2O every 30 seconds until it reached 6 cmH2O or SpO2 dropped to ≤ 80%.

• Selection of optimal PEEP: The optimal PEEP was defined as the intersection point between the alveolar overdistension and collapse curves as measured by the EIT system.

  • Termination Criteria: If persistent hypotension (mean arterial pressure decrease > 15 mmHg) or sustained hypoxemia (SpO2 < 85% for at least 1 minute) occurs during the recruitment maneuver maneuver, the procedure is terminated, and ventilator settings are returned to the parameters used prior to the recruitment maneuver.

Low FiO2 - PEEP table In the control group, patients set PEEP by low FiO2-PEEP table based on ARDSnet protocol.

• Study Type: Interventional
• Enrollment (Estimated): 76
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Trung Van Dinh, MD; Phone Number: (+84) 988519190; Email: dinhvantrung.ptgh@gmail.com

Study Locations

• Vietnam
  • Hanoi, Vietnam
    • Recruiting
    • Intensive Care Center, Bach Mai Hospital
    • Contact: Son Ngoc Do, Prof. PhD. MD; Phone Number: (+84) 914669880; Email: sonngocdo@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 18 years.
• Intubated moderate and severe ARDS according to the New Global Definition (PaO2/FiO2 ≤200 mmHg).
• Used continuous sedation with or without paralysis.

Exclusion Criteria:

• Presence of pneumothorax that is either undrained or newly occurred.
• Unstable hemodynamics with a mean arterial pressure < 60 mmHg and unresponsive to resuscitation measures, and/or heart rate < 60 bpm.
• Contraindications for EIT (pacemakers, automatic external defibrillators, cases of chest trauma or recent chest surgery limiting EIT belt application).
• Pregnancy.
• Severe neuromuscular disease.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: EIT-PEEP setting; Patients will have PEEP settings determined by EIT guidance following a stepwise decremental PEEP trial	Device: electrical impedance tomography; Before initiating recruitment maneuver, all patients were placed on mechanical ventilation set according to the ARDSnetwork strategy for 10 minutes, ensuring SpO2 of 88-95%, PaO2 of 55-80 mmHg, and a mean arterial pressure (MAP) ≥ 65 mmHg.; PEEP was incrementally increased by 5 cmH2O every minute: from 10 to 15, to 20, and finally to 25 cmH2O, with a maximum pressure limit of 40 cmH2O.; Following recruitment maneuver at the final PEEP level, the process of identifying the optimal PEEP was initiated.; Then, PEEP will be set to 20 cmH2O and was gradually decreased by 2 cmH2O every 30 seconds until it reached 6 cmH2O or SpO2 dropped to ≤ 80%.; Selection of optimal PEEP: The optimal PEEP was defined as the intersection point between the alveolar overdistension and collapse curves as measured by the EIT system.
Placebo Comparator: ARDSNet-PEEP setting; PEEP will be adjusted using the low FiO2-PEEP table to achieve oxygenation targets: SpO2 between 88% and 95% and PaO2 between 55 mmHg and 80 mmHg	Other: Non-EIT; Patients will have PEEP set using the low FiO2-PEEP table, based on the ARDSnet protocol

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Oxygenation	PaO2/FiO2 will be evaluated via arterial blood gas analysis every day during the first week treatment.	at day 1, 2, 3, 4, 5, 6, 7
Pulmonary Mechanic	Static Compliance	at day 1, 2, 3, 4, 5, 6, 7

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ventilator free days	Ventilator free days	up to 28 days
Length of ICU stay	Days of ICU stay	up to 28 days
Length of mechanical ventilated days	Days of received mechanical ventilation	up to 28 days
Pneumothorax or barotrauma	new-onset of pneumothorax and barotrauma	up to 28 days
Rescue therapies	Neuromuscular blocker, prone postition, ECMO	up to 7 days
SOFA	Sequential Organ Failure Assessment	at day 1, 3, 7
Mortality	the survival rate(survival/total) during hospital stay	up to 2 months

Collaborators and Investigators

• Sponsor: Vietnam Military Medical University
• Collaborators: Hanoi Medical University; Bach Mai Hospital

Publications and helpful links

General Publications

• Costa EL, Borges JB, Melo A, Suarez-Sipmann F, Toufen C Jr, Bohm SH, Amato MB. Bedside estimation of recruitable alveolar collapse and hyperdistension by electrical impedance tomography. Intensive Care Med. 2009 Jun;35(6):1132-7. doi: 10.1007/s00134-009-1447-y. Epub 2009 Mar 3.
• Matthay MA, Arabi Y, Arroliga AC, Bernard G, Bersten AD, Brochard LJ, Calfee CS, Combes A, Daniel BM, Ferguson ND, Gong MN, Gotts JE, Herridge MS, Laffey JG, Liu KD, Machado FR, Martin TR, McAuley DF, Mercat A, Moss M, Mularski RA, Pesenti A, Qiu H, Ramakrishnan N, Ranieri VM, Riviello ED, Rubin E, Slutsky AS, Thompson BT, Twagirumugabe T, Ware LB, Wick KD. A New Global Definition of Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med. 2024 Jan 1;209(1):37-47. doi: 10.1164/rccm.202303-0558WS.
• Jimenez JV, Weirauch AJ, Culter CA, Choi PJ, Hyzy RC. Electrical Impedance Tomography in Acute Respiratory Distress Syndrome Management. Crit Care Med. 2022 Aug 1;50(8):1210-1223. doi: 10.1097/CCM.0000000000005582. Epub 2022 May 23.

Study record dates

Study Major Dates

• Study Start (Actual): August 15, 2024
• Primary Completion (Estimated): December 15, 2026
• Study Completion (Estimated): December 30, 2026

Study Registration Dates

• First Submitted: December 9, 2024
• First Submitted That Met QC Criteria: December 9, 2024
• First Posted (Estimated): December 13, 2024

Study Record Updates

• Last Update Posted (Estimated): December 13, 2024
• Last Update Submitted That Met QC Criteria: December 9, 2024
• Last Verified: August 1, 2024

More Information

Terms related to this study

• Keywords: Mechanical Ventilation; pulmonary mechanics; electrical impedance tomography; Positive End-Expiratory Pressure; Acute respiratory syndrome distress; blood oxygenation
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Lung Diseases; Respiration Disorders; Infant, Premature, Diseases; Infant, Newborn, Diseases; Respiratory Distress Syndrome; Respiratory Distress Syndrome, Newborn
• Other Study ID Numbers: TrungHSTC 5532/BM-HDDD

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No