Incremental and Decremental PEEP Titration by Diverse Strategies in Subjects With ARDS: A Prospective Physiological Study (ARDS，PEEP)

Research on Precision Individualized Mechanical Ventilation Strategies for ARDS Guided by Electrical Impedance Tomography Monitoring and Evaluation of the Differences in Ventilation and Perfusion Distribution

The investigators conducted a prospective physiological observation study on ARDS population, described their physiological and EIT indexes with various PEEP titration methods, and also compared and analyzed those indexes to determine whether there were differences among various PEEP titration methods.The objective of this study was to explore and uncover the physiological differences in response to optimal PEEP in different ways，and analyzed the correlation of the optimal PEEP in these different ways.

Study Overview

• Status: Completed
• Conditions: ARDS
• Intervention / Treatment: Device: Esophageal pressure catheter

• Study Type: Observational
• Enrollment (Actual): 31

Contacts and Locations

Study Locations

• China
  • Sichuan
    • Chengdu, Sichuan, China, 610041
      • West China Hospital of Sichuan University, Chengdu

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

ntubated and mechanical ventilated patients over 18 years with moderate-severe ARDS (PaO2 /FIO2 ,200 mm Hg) admitted to the ICU within 48 hours were enrolled from October 2022 to July 2024.

Description

Inclusion Criteria:

• Intubated and mechanical ventilated patients in ICU within 48 hours
• Be over 18 years old
• With moderate-severe ARDS (PaO2 /FIO2 ,200 mm Hg)

Exclusion Criteria:

• Severe chronic obstructive pulmonary diseases
• Pulmonary bulla(>1CM) or pneumothorax or pneumomediastinum or subcutaneous emphysema
• Pregnancy
• BMI≥35kg/m2
• Suspected pulmonary vascular hemorrhage
• Disturbance of consciousness or intracranial hypertension
• Severe cardiac dysfunction (New York Heart Association Class III or IV, acute -Coronary syndrome or persistent ventricular tachyarrhythmia), cardiogenic shock or after major cardiac surgery
• Hemodynamic instability (i.e., mean arterial pressure [MAP]<60 mm Hg despite vasopressor use
• The medical team considering short periods of high pressure to be unsafe
• Contraindications for placement of esophageal pressure catheters (e.g., esophageal varix or fracture of skull base)
• Contraindications for EIT monitoring (including pacemaker, or cutaneous diseases which limiting electrode placement)
• Agonal stage or end-stages of diseases

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
the selected PEEP values	1. Method-specific selected PEEP values; Description: The principal endpoint was the set of 15 method-specific selected PEEP values determined for each patient.; Unit of Measure: cmH₂O	through study completion, an average of 1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
SpO2/FiO2 at each selected PEEP	SpO2/FiO2 measured at each selected PEEP. This study will separately measure peripheral oxygen saturation (SpO₂, unit: %) and fraction of inspired oxygen (FiO₂, unit: %). Because both measurements share the same unit (%), they will not be reported as separate outcome measures. Instead, they will be aggregated into a single reported value: the SpO₂/FiO₂ ratio (dimensionless). At each selected positive end-expiratory pressure (PEEP) level, the ratio will be calculated as S/F = SpO₂ (%) ÷ FiO₂ (%), and this ratio will be recorded as the final outcome measure.	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
respiratory system compliance value at each selected PEEP	This study will directly record the respiratory system compliance value as measured and displayed by the ventilator (unit: mL/cmH₂O) at each selected PEEP.	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
plateau pressure at each selected PEEP	At each selected positive end-expiratory pressure (PEEP) level, plateau pressure will be directly recorded from the ventilator after performing an inspiratory hold maneuver. This value is displayed by the ventilator in cmH₂O	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
Driving Pressure at each selected PEEP	At each selected positive end-expiratory pressure (PEEP) level, plateau pressure (Pplat, unit: cmH₂O) will be measured via the ventilator, and the corresponding PEEP value (unit: cmH₂O) will be recorded. Driving pressure (ΔP) is calculated as the difference between the two: ΔP = Pplat - PEEP (unit: cmH₂O).	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
End-inspiratory Transpulmonary Pressure (PTPi) at each selected PEEP	After placement of an esophageal pressure catheter, the ventilator will monitor esophageal pressure (Pes) and airway pressure. At each selected positive end-expiratory pressure (PEEP) level, an end-inspiratory hold maneuver will be performed. The end-inspiratory transpulmonary pressure (PTPi) is calculated as the difference between the airway plateau pressure (Pplat) measured during the hold and the corresponding esophageal pressure (Pes): PTPi = Pplat - Pes (unit: cmH₂O).	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
End-expiratory Transpulmonary Pressure (PTPe) at each selected PEEP	After placement of an esophageal pressure catheter, the ventilator will monitor esophageal pressure (Pes) and airway pressure. At each selected positive end-expiratory pressure (PEEP) level, an end-expiratory hold maneuver will be performed. The end-inspiratory transpulmonary pressure (PTPe) is calculated as the difference between the PEEP measured during the hold and the corresponding esophageal pressure (Pes): PTPe = PEEP - Pes (unit: cmH₂O). This calculated value is the single reported outcome measure	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
transpulmonary driving pressure at each selected PEEP	After placement of an esophageal pressure catheter, the ventilator will monitor transpulmonary pressures. At each selected PEEP level, end-inspiratory transpulmonary pressure (PTPi) and end-expiratory transpulmonary pressure (PTPe) are obtained during inspiratory and expiratory hold maneuvers, respectively. Both are measured in cmH₂O. Transpulmonary driving pressure is calculated as the difference: ΔPtp = PTPi - PTPe (unit: cmH₂O).	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
EIT-derived Regional Ventilation Parameters at each selected PEEP level	Using electrical impedance tomography (EIT), the lung is divided into four regions of interest (ROI I to ROI IV) from ventral to dorsal. For each ROI, the percentage of tidal impedance variation relative to total tidal impedance variation is recorded (% of total). unit: cmH₂O	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
the center of ventilation (COV) at each selected PEEP level	the center of ventilation (COV) is calculated as the position of the ventilation center along the ventral-dorsal axis, expressed as a percentage (0% = ventral, 100% = dorsal). this parameter is measured in %	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
CL HP% (overdistension region) at each selected PEEP level	Using electrical impedance tomography (EIT)，based on regional compliance analysis，CL HP% represent the percentage of lung regions showing a decrease in compliance at high PEEP due to overdistension (unit: %).	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process
CL LP% (collapse region) at selected PEEP	Using electrical impedance tomography (EIT)，based on regional compliance analysis，CL LP% represent the percentage of lung regions showing a decrease in compliance at low PEEP due to collapse (unit: %).	baseline, within 5 minutes after the PV-tool measurement, and within 5 minutes after each increment and decrement of PEEP during the PEEP adjustment process

Collaborators and Investigators

• Sponsor: West China Hospital

Study record dates

Study Major Dates

• Study Start (Actual): December 10, 2024
• Primary Completion (Actual): July 28, 2025
• Study Completion (Actual): July 28, 2025

Study Registration Dates

• First Submitted: December 5, 2024
• First Submitted That Met QC Criteria: January 29, 2025
• First Posted (Actual): February 5, 2025

Study Record Updates

• Last Update Posted (Actual): August 26, 2026
• Last Update Submitted That Met QC Criteria: August 21, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: PEEP Titration; 2024YFFK0329 (Other Grant/Funding Number: Sichuan Science and Technology Program); 2024ZD0530000 (Other Grant/Funding Number: Noncommunicable Chronic Diseases-National Science and Technology Major Project)

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
• product manufactured in and exported from the U.S.: No