Impact of PEEP Trials on Ventilation-Perfusion Matching in ARDS Patients

NCT ID: NCT06823804

Last Updated: 2025-12-16

Basic Information

• Recruitment Status: ENROLLING_BY_INVITATION
• Clinical Phase: PHASE2/PHASE3
• Total Enrollment: 120 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2022-12-01
• Study Completion Date: 2025-12-31

Brief Summary

In the treatment of critically ill patients, mechanical ventilation is a key link, and appropriate mechanical ventilation strategies can open the alveoli and improve oxygenation, while inappropriate mechanical ventilation can increase lung injury and seriously affect the prognosis. Ventilator-related lung injury is mainly concentrated in barotrauma, volumetric injury, shear injury, and biological injury, and the monitoring of respiratory ventilation to the level of local ventilation can help to better assess the state of alveolar opening and alveolar collapse, and help to understand the uniformity of gas distribution in the lungs, which is closely related to lung injury. However, how to achieve simple, bedside and real-time lung ventilation and lung volume assessment in clinical work has always been a difficult problem to be overcome. This study intends to explore the changes of local ventilation and blood flow in the lungs during PEEP trail in patients with ARDS monitored by EIT.

Detailed Description

1. Background and Rationale ARDS is associated with heterogeneous lung collapse. The recruitment-to inflation (R/I) ratio has emerged as an index of recruitability, but is usually assessed globally. Electrical impedance tomography (EIT) enables regional assessment of ventilation and may provide more precise determinations of recruitable lung regions, particularly dorsal areas.

2. Objectives Primary objective: To compare the predictive value of regional (dorsal and ventral) versus global R/I for recruitment success in moderate-severe ARDS. Secondary objectives: To classify recruitment phenotypes and evaluate associations with oxygenation, compliance improvement, ventilator-free days, ICU length of stay, and 28-day mortality.

3. Study Design Prospective, single-centre observational cohort study in ICU patients with moderate-severe ARDS. All eligible patients undergo standardised recruitment maneuver and EIT monitoring.

4. Study Setting Ruijin Hospital, Shanghai Jiao Tong University School of Medicine ICU, December 2022 - December 2024.

5. Intervention Standardized PEEP step maneuver from 5 → 15 cmH₂O, maintained for 3 minutes. Continuous EIT monitoring of regional compliance, oxygenation, hemodynamics. Dynamic strain cutoff (>0.6) or adverse events terminate the maneuver. Ventilation mode: volume control, tidal volume 4-6 mL/kg predicted body weight, plateau ≤28-30 cmH₂O, FiO₂ titrated for SpO₂ 88-92%.

6. Measurements EIT-derived ΔEELI in dorsal and ventral regions Regional and global compliance (Crec and Crs) R/I calculated: Crec/Crs at baseline PEEP Airway opening pressure by low-flow inflation method Primary outcome: recruitment success (≥10% compliance improvement + ≥20 mmHg PaO₂/FiO₂ increase) Secondary: ventilator-free days, ICU LOS, 28-day mortality, dynamic strain

7. Statistical Analysis Plan Distribution check by Shapiro-Wilk. Paired tests for within-patient comparisons. ROC curves and Youden index for cut-off selection. Multivariate regression for mortality risk factors. Bonferroni correction for multiple comparisons.

8. Safety Monitoring Terminate RM if: MAP <65 mmHg, SpO₂ <88%, arrhythmia onset, dynamic strain >0.6.

Conditions

ARDS

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: NONE

Study Groups

evaluate the feasibility of using EIT to calculate regional recruitment-to-inflation (R/I) ratios

Regional R/I ratios were computed for the global lung, dorsal (dependent), and ventral (non-dependent) regions of interest (ROIs), which were defined as 50% of the ventro-dorsal lung diameter based on EIT imaging.compare the predictive value of regional (dorsal and ventral) versus global R/I for recruitment success in moderate-severe ARDS.

Group Type: EXPERIMENTAL

10ml of 10% saline is injected centrally

Intervention Type: DRUG

The first phase of the study is an observational study that does not alter the clinical treatment plan.

The experimental group standardized PEEP step maneuver from 5 → 15 cmH₂O, maintained for 3 minutes. Continuous EIT monitoring of regional compliance, oxygenation, hemodynamics. Dynamic strain cutoff (>0.6) or adverse events terminate the maneuver.

Ventilation mode: volume control, tidal volume 4-6 mL/kg predicted body weight, plateau ≤28-30 cmH₂O, FiO₂ titrated for SpO₂ 88-92%.

Interventions

10ml of 10% saline is injected centrally

The first phase of the study is an observational study that does not alter the clinical treatment plan.

The experimental group standardized PEEP step maneuver from 5 → 15 cmH₂O, maintained for 3 minutes. Continuous EIT monitoring of regional compliance, oxygenation, hemodynamics. Dynamic strain cutoff (>0.6) or adverse events terminate the maneuver.

Ventilation mode: volume control, tidal volume 4-6 mL/kg predicted body weight, plateau ≤28-30 cmH₂O, FiO₂ titrated for SpO₂ 88-92%.

Intervention Type: DRUG

Other Intervention Names

Electrical impedance tomography

Eligibility Criteria

Inclusion Criteria

• Patients who meet the Berlin definition of ARDS and have been treated with mechanical ventilation (clinical diagnosis of ARDS by the attending ICU physician)
• PaO₂/FiO₂ ≤150 mmHg

Exclusion Criteria

• Age< 18 or >90 years
• Pneumothorax, pneumomediastinum
• Hemodynamic instability (rising vasopressor need in <6h)
• Contraindications to RM or EIT

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 90 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Ruijin Hospital

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Hongping Qu

Role: STUDY_CHAIR

Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine

Jialin Liu

Role: PRINCIPAL_INVESTIGATOR

Department of Geriatrics，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine

rui zhang

Role: STUDY_DIRECTOR

Department of Critical Care Medicine，Ruijin Hospital

Locations

Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine，Shanghai，China.

Shanghai, Shanghai Municipality, China

Countries

China

Other Identifiers

2022325

Identifier Type: -

Identifier Source: org_study_id