The Physiological Effect of RCexp on Ventilation/Perfusion Distribution

The Physiological Effect of RCexp on Ventilation/Perfusion Distribution in Patients With ARDS

With the exception of setting the positive end-expiratory pressure (PEEP), the expiratory phase is commonly overlooked during MV. The expiratory time constant (RCexp) plays an important role in understanding the mechanical properties of the respiratory system in patients receiving mechanical ventilation. However, it is unclear that the effect of expiratory time constant on the ventilation and perfusion distribution.

Study Overview

• Status: Recruiting
• Conditions: Acute Respiratory Distress Syndrome; Mechanical Ventilation
• Intervention / Treatment: Other: RCexp

Detailed Description

With the exception of setting the positive end-expiratory pressure (PEEP), the expiratory phase is commonly overlooked during MV. The expiratory time constant (RCexp) plays an important role in understanding the mechanical properties of the respiratory system in patients receiving mechanical ventilation. However, it is unclear that the effect of expiratory time constant on the ventilation and perfusion distribution.

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: yuan xue yan, MD; Phone Number: +86-15901599659; Email: 18826401594@163.com

Study Locations

• China
  • Jiangsu
    • Nanjing, Jiangsu, China, 210009
      • Recruiting
      • Zhongda Hospital, School of Medicine, Southeast University
      • Contact: yan xue yuan; Phone Number: 032-83262550; Email: 18826401594@163.com

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

1. Intubated patients with moderate and severe ARDS (Berlin definition, PaO2/FiO2 ≤200 mmHg at PEEP 5 cmH2O)
2. undergoing deep sedation on controlled mechanical ventilation within72 hours after ARDS onset

Description

Inclusion Criteria:

adult patients with ARDS receiving mechanical ventilation no more than 72 hours

Exclusion Criteria:

1. age <18 years old
2. patient undergoing legal protection
3. contra-indications to EIT (e. g. severe chest trauma or wounds)
4. pneumothorax
5. patient undergoing ECMO
6. pregnancy

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
mechanically ventilated patients with ARDS	Other: RCexp; patients received different RCexp

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in ventilation/perfusion mismatch	ventilation/perfusion mismatch is measured by EIT	4 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in dead space	dead space is measured by EIT	4 hours
Difference in shunt	shunt is measured by EIT	4 hours

Collaborators and Investigators

• Sponsor: Southeast University, China

Study record dates

Study Major Dates

• Study Start (Estimated): November 30, 2025
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: April 2, 2025
• First Submitted That Met QC Criteria: April 2, 2025
• First Posted (Actual): April 9, 2025

Study Record Updates

• Last Update Posted (Actual): November 26, 2025
• Last Update Submitted That Met QC Criteria: November 20, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Lung Diseases; Respiration Disorders; Respiratory Distress Syndrome
• Other Study ID Numbers: RCexp_ventilation/perfusion

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