Personalized Ventilation Based on Ventilation-perfusion Mismatch and Lung Recruitability

NCT ID: NCT06430554

Last Updated: 2026-02-03

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 40 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-06-08
• Study Completion Date: 2026-06-30

Brief Summary

This observational study will explore the effects of PEEP and position on regional lung ventilation-perfusion mismatch by electrical impedance tomography (EIT) in moderate-to-severe ARDS patients with different lung recruitability.

Detailed Description

Acute respiratory distress syndrome (ARDS) is characterized by impaired ventilation-perfusion matching, which not only indicates the severity of the condition but also contributes to ventilation-induced lung injury. Higher positive end-expiratory pressure (PEEP) and prone position could improve ventilation-perfusion mismatch by recruiting collapsed lungs and facilitating more homogeneous ventilation, but these benefits might depend on lung recruitability. The present study aims to elucidate the regional effect of PEEP(low and high) and body position(supine and prone) on the ventilation-perfusion matching. Also endeavors to establish correlations between alterations in ventilation-perfusion matching patterns and the inherent lung recruitability.

Participants will be deeply sedated and paralyzed, ventilated in volume-controlled with protective ventilation (tidal volume=6-8 mL/Kg of predicted body weight and respiratory rate set to obtain normal pH). Then the patients will be sequentially assigned to each of four conditions as follows:

Low PEEP, supine position; High PEEP, supine position; Low PEEP, prone position; High PEEP, prone position. High PEEP and low PEEP is defined as 15 cmH2O and 5 cmH2O (or airway opening pressure, either of which was higher) respectively. Each measurement (e.g., arterial blood gas analysis, respiratory parameters, hemodynamics, EIT measurements) will be performed at least 15 minutes after changing ventilator settings and at least 1 hour after changing body positions. The timing of turning patients from supine to prone position is determined by the clinical team.

To assess lung recruitability, a single-breath derecruitment maneuver will be performed by changing PEEP 15 to 5 cmH2O (or airway opening pressure, either of which was higher) in supine position. Patients with recruitment-inflation ratio over the median value are defined as high recruiters.

EIT data will be collected by standard device (Infinity C500, Drager, Germany) with a sample rate of 50 Hz. The EIT belt will be placed directly below the armpits, between the third and fifth intercostal spaces. This positioning of the EIT belt will be maintained consistently during both supine and prone positions. A bolus of 10 ml 5% NaCl will be injected during a respiratory pause (≥8 s) through the central venous catheter to assess lung ventilation and perfusion distributions. The primary endpoint is EIT-based ventilation-perfusion matching (V/Q match%).

Conditions

Respiratory Distress Syndrome; Positive-Pressure Respiration; Mechanical Ventilation

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Eligibility Criteria

Inclusion Criteria

1. age ≥18 years

2. Moderate-to-severe ARDS as per the 2023 ESICM definition

3. Undergoing invasive mechanical ventilation

4. Planned prone position based on the attending physicians' decisions

5. Signed informed consent

Exclusion Criteria

1. age ≥85 years

2. Pregnancy

3. Severe hemodynamic instability (> 30% increase in vasopressors in the last 6 hours or norepinephrine > 0.5 µg/kg/min)

4. Clinically suspected elevated intracranial pressure (>18 mm Hg)

5. Bronchopleural fistula

6. Contraindication to EIT monitoring (e.g. burns, pacemaker, thoracic wounds limiting electrode belt placement)

7. Severe hypernatremia (>170mmol/L)

8. Re-admission of patients already enrolled in this study, or patients who are participating in other studies

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Zhongda Hospital

OTHER

Sponsor Role: lead

Responsible Party

Fengmei Guo

Director of Intensive Care Unit, Principal Investigator, Clinical Professor, Zhongda Hospital, Southeast University, China

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Fengmei Guo, PhD, MD

Role: STUDY_CHAIR

Nanjing Zhongda Hospital, Southeast University

Locations

Zhongda Hospital, Southeast University

Nanjing, Jiangsu, China

Site Status: RECRUITING

Countries

China

Central Contacts

Fengmei Guo, PhD, MD

Role: CONTACT

fmguo2022@163.com

+8613813841261

Zhiqian Zha, MM

Role: CONTACT

15505083904@163.com

+8615505083904

Facility Contacts

Fengmei Guo, Ph.D

Role: primary

fmguo2022@163.com

+8613813841261

Other Identifiers

2024ZDSYLL044-P01

Identifier Type: -

Identifier Source: org_study_id