End-Expiratory Diaphragmatic Residual Contraction Index for Identifying Intrinsic PEEP and Assisting PEEP Titration: A Prospective Physiological Study

NCT07697703 | Not Yet Recruiting

• 1 other identifier: 20260627
• Study Type: observational
• Target: 100
• Locations: 0 countries
• Sites: N/A

Brief Summary

This study proposes the End-expiratory Diaphragmatic Residual Contraction (EDRC) index to quantify residual diaphragmatic activity at end-expiration during Pressure Support Ventilation (PSV) mode. The study aims to validate the relationship between EDRC and dynamic intrinsic PEEP (PEEPi), triggering load, patient-ventilator asynchrony, and PEEP responsiveness through a brief, standardized PEEP titration trial conducted within a clinically safe range. This will provide a basis for subsequent individualized PEEP setting guided by EDRC.

Conditions

Speckle Tracking; Diaphragm

Outcome Measures

Primary Outcomes (1)

• Diagnostic Efficacy of EDRC-AUC for Identifying Clinically Significant Dynamic Intrinsic PEEP

  The primary outcome is the diagnostic efficacy of the End-Expiratory Diaphragmatic Residual Contraction Area Under the Curve (EDRC-AUC) in identifying clinically significant dynamic intrinsic PEEP (PEEPi,dyn ≥ 5 cmH2O) in patients undergoing Pressure Support Ventilation (PSV). The diagnostic performance will be evaluated using Receiver Operating Characteristic (ROC) curve analysis, reporting the Area Under the Curve (AUC), optimal cut-off value, sensitivity, specificity, positive predictive value, and negative predictive value, with esophageal manometry and flow curves as the reference standard.

  During the short-term PEEP step trial (each PEEP level is maintained for 5-10 minutes)

Secondary Outcomes (6)

• Correlation between EDRC-AUC and Respiratory Drive/Load Indices

  During the short-term PEEP step trial (each PEEP level maintained for 5-10 minutes) and within 30 minutes post-trial

• Incidence of Patient-Ventilator Asynchrony Events

  During the short-term PEEP step trial (each PEEP level maintained for 5-10 minutes) and within 30 minutes post-trial.

• Agreement between EDRC-Guided PEEP and Esophageal Manometry-Guided PEEP

  During the short-term PEEP step trial (each PEEP level maintained for 5-10 minutes) and within 30 minutes post-trial.

• Trends in Diaphragmatic Contraction Dynamics Across PEEP Levels

  During the short-term PEEP step trial (each PEEP level maintained for 5-10 minutes) and within 30 minutes post-trial.

• Feasibility and Inter-Observer Reliability of EDRC Ultrasound Measurements

  During the short-term PEEP step trial (each PEEP level maintained for 5-10 minutes) and within 30 minutes post-trial.

Study Arms (1)

Patients Undergoing PEEP Step Trial and EDRC Assessment

All enrolled patients will receive a standardized, short-term PEEP step trial while in Pressure Support Ventilation (PSV) mode. The trial consists of sequentially applying PEEP levels of Baseline, -2, +2, +4, and +6 cmH2O relative to the set PEEP. At each step, respiratory mechanics and patient-ventilator synchrony will be monitored. The primary intervention of interest is the assessment of End-Expiratory Diaphragmatic Residual Contraction (EDRC) via ultrasound to identify the presence of intrinsic PEEP (PEEPi) and to determine the optimal level of extrinsic PEEP that minimizes diaphragmatic effort and asynchrony.

Device: Short-term PEEP Step Trial and EDRC Ultrasound Assessment

Interventions

Short-term PEEP Step Trial and EDRC Ultrasound Assessment DEVICE

This intervention involves a standardized, short-term PEEP step trial combined with a novel physiological assessment. During the trial, external PEEP is systematically adjusted in 2 cmH2O increments (Baseline, -2, +2, +4, +6 cmH2O) while maintaining stable Pressure Support Ventilation (PSV) settings. Simultaneously, the End-Expiratory Diaphragmatic Residual Contraction (EDRC) index is evaluated using diaphragm ultrasound speckle tracking. This distinguishes the intervention by providing a non-invasive, real-time quantification of residual diaphragmatic tension at end-expiration, which serves as a surrogate marker for dynamic intrinsic PEEP (PEEPi) and trigger load, distinguishing it from traditional static measurements or esophageal manometry alone.

Patients Undergoing PEEP Step Trial and EDRC Assessment

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population will consist of adult patients ($\\ge$ 18 years) admitted to the Intensive Care Unit (ICU) who are receiving invasive mechanical ventilation in Pressure Support Ventilation (PSV) mode. Participants will be recruited from the ICU at \[Insert Name of Hospital/Institution\]. The population is characterized by patients who are clinically assessed as having a risk of dynamic intrinsic PEEP (PEEPi,dyn) or are undergoing a spontaneous breathing trial (SBT) as part of the weaning process. All enrolled patients will have an indwelling esophageal balloon catheter placed for the measurement of esophageal pressure (Pes), which serves as the reference standard for respiratory mechanics. Patients will be screened for eligibility based on hemodynamic stability and the ability to tolerate the study procedures. Specific exclusion criteria include pregnancy, severe esophageal pathology, severe hypoxemia, and conditions precluding diaphragmatic ultrasound imaging (e.g., chest wall tra

You may qualify if:

• Age ≥ 18 years. Patients receiving invasive mechanical ventilation in Pressure Support Ventilation (PSV) mode.
• Clinically assessed as having a risk of dynamic intrinsic PEEP (PEEPi,dyn) or experiencing difficult weaning from mechanical ventilation.
• Presence of an indwelling esophageal balloon catheter (for reference standard measurements).
• Provision of written informed consent from the patient or legally authorized representative.

You may not qualify if:

• Pregnancy or lactation. Known esophageal diseases (e.g., esophageal varices, strictures, recent esophageal surgery) or contraindications to esophageal catheter placement.
• Severe hemodynamic instability (e.g., requiring high-dose vasoactive support, uncontrolled arrhythmias).
• Severe hypoxemia (PaO2/FiO2 \< 100 mmHg) or severe hypercapnia with hemodynamic compromise at baseline.
• Conditions precluding ultrasound assessment of the diaphragm (e.g., extensive chest wall trauma, large pleural effusion, severe subcutaneous emphysema).
• Active spontaneous breathing with severe patient-ventilator asynchrony that cannot be stabilized during the trial.
• Anticipated extubation or withdrawal of life-sustaining treatment within the next 24 hours.
• Participation in another interventional clinical trial within the last 30 days.

Sponsors & Collaborators

• Sir Run Run Shaw Hospital: lead

Related Publications (4)

• Haudebourg AF, Maraffi T, Tuffet S, Perier F, de Prost N, Razazi K, Mekontso Dessap A, Carteaux G. Refractory ineffective triggering during pressure support ventilation: effect of proportional assist ventilation with load-adjustable gain factors. Ann Intensive Care. 2021 Oct 20;11(1):147. doi: 10.1186/s13613-021-00935-0.

  PMID: 34669080 RESULT

• Umbrello M, Formenti P, Longhi D, Galimberti A, Piva I, Pezzi A, Mistraletti G, Marini JJ, Iapichino G. Diaphragm ultrasound as indicator of respiratory effort in critically ill patients undergoing assisted mechanical ventilation: a pilot clinical study. Crit Care. 2015 Apr 13;19(1):161. doi: 10.1186/s13054-015-0894-9.

  PMID: 25886857 RESULT

• Chao DC, Scheinhorn DJ, Stearn-Hassenpflug M. Patient-ventilator trigger asynchrony in prolonged mechanical ventilation. Chest. 1997 Dec;112(6):1592-9. doi: 10.1378/chest.112.6.1592.

  PMID: 9404759 RESULT

• MacIntyre NR, Cheng KC, McConnell R. Applied PEEP during pressure support reduces the inspiratory threshold load of intrinsic PEEP. Chest. 1997 Jan;111(1):188-93. doi: 10.1378/chest.111.1.188.

  PMID: 8996015 RESULT

Central Study Contacts

Huiqing Ge, MD

CONTACT

+8613588706787; gehq@zju.edu.cn

YIqing Xu, Master

CONTACT

+86 13634115344; xuyiqing@srrsh.com

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director of Respiratory Medicine

Study Record Dates

• First Submitted: July 5, 2026
• First Posted: July 13, 2026
• Study Start (Estimated): August 21, 2026
• Primary Completion (Estimated): August 24, 2027
• Study Completion (Estimated): September 3, 2027
• Last Updated: July 13, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share