Impact of PEEP Trials on Ventilation-Perfusion Matching in ARDS Patients
- Conditions
- ARDS
- Interventions
- Drug: 10ml of 10% saline is injected centrally
- Registration Number
- NCT06823804
- Lead Sponsor
- Ruijin Hospital
- 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
Development and Clinical Application of EIT-based Pulmonary Blood Flow Imaging in Monitoring PEEP Trial Strategies for ARDS Patients: A Prospective Study
Background and Significance:
Mechanical ventilation is a crucial component in the treatment of critically ill patients. While mechanical ventilation strategies can improve oxygenation through alveolar recruitment, inappropriate ventilation can exacerbate lung injury and worsen outcomes.
Recent studies have highlighted the value of individualized ventilation strategies tailored to the unique mechanical properties of each patient's lungs . such as bedside chest radiography, CT scanning, and lung ultrasound, have limitations including radiation exposure, intermittent nature of assessment, and impracticality for continuous monitoring. Electrical impedance tomography (EIT) offers a promising solution as a radiation-free, real-time bedside monitoring tool that can assess regional ventilation distribution, lung volume, and respiratory mechanics.
Research Objectives:
The primary objective of this study is to investigate changes in regional ventilation-perfusion relationships during PEEP trials in ARDS patients using EIT monitoring. the investigators aim to develop and validate EIT-based pulmonary blood flow imaging techniques and evaluate their utility in guiding mechanical ventilation strategies.
Methods:
This prospective observational study will be conducted at the Department of Critical Care Medicine, Shanghai Jiao Tong University School of Medicine Affiliated Ruijin Hospital between July 2022 and nov. 2025. The investigators will enroll patients meeting ARDS criteria who require mechanical ventilation. The study will utilize the Dräger EIT device, which has over a decade of clinical application history and established data acquisition protocols.
Intervention Description： First phase: Observational study using EIT monitoring for lung ventilation and blood flow assessment without altering clinical management.Evaluate the feasibility of using electrical impedance tomography (EIT) to calculate regional recruitment-to-inflation (R/I) ratios and identify distinct recruitment phenotypes in ARDS patients.
Second phase: Comparing impact of EIT-guided versus standard ventilation strategies on ARDS patient outcomes.
PEEP Trial Protocol:
Patients will undergo standardized PEEP trials with the following parameters:
* FiO2 will be adjusted to 100%
* Volume-controlled mode with respiratory rate of 12 breaths/minute
* I:E ratio of 1:1
* Tidal volume of 6 mL/kg predicted body weight
* PEEP levels of 0, 5, 10,15 and 20 cmH2O, each maintained for 2 minutes
* Continuous hemodynamic monitoring during PEEP trials
* Safety limits: Peak pressure not exceeding 45 cmH2O
* Immediate pressure reduction if peak pressure exceeds 40 cmH2O after 2 minutes
Data Collection:
The investigators will record:
* Baseline vital signs including heart rate, blood pressure, SpO2, respiratory rate
* EIT ventilation parameters including EELI, GI index, and ROI analysis
* EIT perfusion parameters including V/Q ratio, dead space percentage, and shunt fraction
* Continuous hemodynamic monitoring during PEEP trials
* Arterial blood gas analyses at defined time points
Calculation Phase:
* Recruited volume (ΔVrec) was calculated as the difference between measured and predicted end-expiratory lung impedance (ΔEELI).
* Recruited lung compliance (Crec) was determined as ΔVrec divided by the PEEP increment (ΔPEEP).
* The R/I ratio was defined as Crec divided by the compliance of the respiratory system (Crs) at low PEEP.
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.
Outcome Measures:
Primary outcomes:
* Changes in regional ventilation-perfusion matching during PEEP trials
* Correlation between EIT-derived parameters and clinical outcomes
* the difference between dorsal and global R/I ratios in predicting recruitment responses
Secondary outcomes:
* Development of standardized EIT-based pulmonary blood flow monitoring protocols
* Establishment of PEEP titration guidelines based on V/Q matching
* Changes in oxygenation (ΔPaO₂/FiO₂).
* Improvements in lung compliance.
* Dynamic strain measurements.
* Ventilator-free days at 28 days, ICU length of stay, and 28-day mortality.
Statistical Analysis:
Sample size calculation is based on expected changes in EELI parameters, with α=0.05 and β=0.1. Data will be analyzed using repeated measures analysis for trends in EIT parameters across different PEEP levels. Multiple regression analysis will be used to evaluate relationships between EIT parameters and clinical outcomes.
Expected Impact:
* This study aims to advance our understanding of regional ventilation-perfusion relationships in ARDS patients and develop more precise, individualized mechanical ventilation strategies. The findings may lead to improved patient outcomes through better-guided PEEP titration and ventilation management based on real-time EIT monitoring of both ventilation and perfusion parameters.
* This study aims to evaluate the feasibility of using electrical impedance tomography (EIT) to calculate regional recruitment to inflation (R/I) ratios and identify distinct recruitment phenotypes in ARDS patients.
Recruitment & Eligibility
- Status
- ENROLLING_BY_INVITATION
- Sex
- All
- Target Recruitment
- 120
- Patients who meet the Berlin definition of ARDS and have been treated with mechanical ventilation (clinical diagnosis of ARDS by the attending ICU physician)
- Age< 18 or >90 years
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description nvestigating the detection technology of EIT monitoring for patient lung ventilation and blood flow. 10ml of 10% saline is injected centrally Incorporating ARDS patients on mechanical ventilation, comparing the impact of EIT-V/Q monitoring-guided ventilation strategies and conventional lung-protective ventilation strategies on the prognosis of ARDS patients. Investigating the EIT-V/Q guided ventilation strategies using invasive and non-invasive methods. 10ml of 10% saline is injected centrally The experimental group select the optimal pulmonary blood flow PEEP By Electrical impedance tomography. The control group was selected best PEEP according to the PEEP table .
- Primary Outcome Measures
Name Time Method Correlation between EIT-derived parameters and clinical outcomes From enrollment to the end of treatment at 28-day Correlation analysis between EIT-derived parameters \[e.g., GI index (100%), ROI (100%), V/Q ratio, percentage of dead space (100%)\] and clinical outcomes\[e.g., 28-day mortality\]
28-day mortality From enrollment to the end of treatment at 28 days Statistical analysis of 28-day mortality
Improvements in lung compliance From enrollment to the end of treatment at 7 days Change in lung compliance measured by EIT and Ventilator (C=△V/△P)during PEEP trials from baseline to 30 minutes at each PEEP level (0，5, 10, 15 and 20 cmH2O)
Change in Sequential Organ Failure Assessment (SOFA) score from baseline to day 7 From enrollment to the end of treatment at 7 days Change in Sequential Organ Failure Assessment (SOFA) score from baseline to day 7
Duration of mechanical ventilation from enrollment to successful weaning From enrollment to the end of treatment at 7 days Duration of mechanical ventilation in days from enrollment to successful weaning
- Secondary Outcome Measures
Name Time Method Change in dyspnea severity From enrollment to the end of treatment at 7 days Change in dyspnea severity from baseline to day 7 measured by Visual Analog Scale (VAS) score (range 0-100)
Changes in regional ventilation-perfusion matching during PEEP trials From enrollment to the end of treatment at 7 days Change in ventilation-perfusion ratio measured by EIT during PEEP trials from baseline to 30 minutes at each PEEP level (0，5, 10, 15 and 20 cmH2O)
Change in PaO2/FiO2 ratio From enrollment to the end of treatment at 7 days Change in PaO2/FiO2 ratio from baseline to day 7 measured by arterial blood gas analysis
Length of ICU stay From enrollment to the end of treatment at 7 days Length of ICU stay in days
Incidence of adverse events From enrollment to the end of treatment at 7 days Incidence of adverse events as assessed by Common Terminology Criteria for Adverse Events (CTCAE) v4.0
Related Research Topics
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Trial Locations
- Locations (1)
Department of Critical Care Medicine，Ruijin Hospital，Shanghai Jiao Tong University School of Medicine，Shanghai，China.
🇨🇳Shanghai, Shanghai, China