Brain Monitoring During PEEP-Based Respiratory Therapy in Critically Ill Patients

NCT07716787 | Recruiting

• 1 other identifier: XJS-2024-08
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

Mechanical ventilation is commonly used in critically ill patients with acute brain injury. Positive end-expiratory pressure (PEEP) and lung recruitment maneuvers are important ventilator strategies for improving oxygenation, but they may also influence cerebral blood flow, systemic hemodynamics, carbon dioxide levels, and brain electrical activity. The effects of PEEP-related ventilator changes on cortical function in neurocritical care patients remain insufficiently understood. This prospective observational physiological study will evaluate changes in brain electrical activity and cerebral blood flow during clinically indicated lung recruitment maneuvers and PEEP adjustments in mechanically ventilated neurocritical care patients. Multimodal monitoring will include electroencephalography (EEG), transcranial Doppler ultrasound, invasive arterial blood pressure, end-tidal carbon dioxide, and routine clinical variables. EEG-derived measures, including delta power ratio and related frequency-domain indicators, will be used to describe cortical activity. Cerebral blood flow velocity and low-frequency neurovascular coupling measures will be explored as secondary physiological outcomes. The study will examine whether PEEP-related changes are associated with alterations in EEG activity, cerebral blood flow, and neurovascular coupling, and whether these responses differ according to clinical status. The results may help improve understanding of brain-lung interactions during mechanical ventilation and inform future studies on individualized ventilation strategies in neurocritical care.

Conditions

Mechanical Ventilation; Acute Brain Injury; Neurocritical Care

Keywords

Mechanical Ventilation; Positive End-Expiratory Pressure; Neurocritical Care; Brain-Lung Interaction; Neurovascular Coupling; Electroencephalography; Transcranial Doppler; Cerebral Blood Flow

Outcome Measures

Primary Outcomes (1)

• Change in EEG Delta Power Ratio During PEEP-Based Respiratory Interventions

  Change in electroencephalography (EEG)-derived delta power ratio (DPR) measured before, during, and after recruitment maneuvers and positive end-expiratory pressure (PEEP) adjustments. DPR is calculated as the proportion of delta-band power relative to total EEG power and is used as an indicator of cortical electrophysiological activity.

  During ventilator interventions (baseline, intervention, and recovery periods; approximately 30 minutes)

Secondary Outcomes (3)

• Change in Cerebral Blood Flow Velocity

  During ventilator interventions (approximately 30 minutes)

• Change in Neurovascular Coupling Index

  During ventilator interventions (approximately 30 minutes)

• Change in Mean Arterial Pressure

  During ventilator interventions (approximately 30 minutes)

Study Arms (1)

PEEP-Based Respiratory Intervention

EXPERIMENTAL

Procedure: Recruitment Maneuver; Procedure: Positive End-Expiratory Pressure Adjustment

Interventions

Recruitment Maneuver PROCEDURE

A standardized lung recruitment maneuver performed during mechanical ventilation to transiently increase airway pressure and reopen collapsed alveoli. Physiological responses are continuously monitored using multimodal neuromonitoring and hemodynamic monitoring systems.

PEEP-Based Respiratory Intervention

Positive End-Expiratory Pressure Adjustment PROCEDURE

Positive end-expiratory pressure (PEEP) levels are adjusted according to the study protocol during mechanical ventilation. Cerebral electrophysiological activity, cerebral blood flow, systemic hemodynamics, and respiratory parameters are continuously recorded during PEEP modifications.

PEEP-Based Respiratory Intervention

Eligibility Criteria

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

You may qualify if:

• Age ≥18 years.
• Admission to the neurocritical care unit with acute brain injury requiring intensive care management.
• Receiving invasive mechanical ventilation.
• Undergoing clinically indicated recruitment maneuvers and positive end-expiratory pressure (PEEP) adjustments.
• Availability of an adequate temporal acoustic window for transcranial Doppler monitoring.
• Written informed consent obtained from the participant or a legally authorized representative.

You may not qualify if:

• Pregnancy.
• Hemodynamic instability precluding recruitment maneuvers or PEEP adjustments.
• Severe cardiac dysfunction judged by the treating physician to contraindicate study procedures.
• Inability to obtain adequate transcranial Doppler signals.
• Conditions preventing EEG monitoring, including extensive scalp injury or dressings that preclude electrode placement.
• Withdrawal of informed consent.

Sponsors & Collaborators

• Shengli Oilfield Hospital: lead

Study Sites (1)

Shengli Oilfield Central Hospital

Dongying, Shandong, 257034, China

RECRUITING

MeSH Terms

Conditions

Brain Injuries

Condition Hierarchy (Ancestors)

Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Craniocerebral Trauma; Trauma, Nervous System; Wounds and Injuries

Central Study Contacts

Min Xu

CONTACT

+8613864708968; xuminicu@163.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director, Neurocritical Care Unit; Chief Physician

Model Details: All enrolled participants undergo the same study procedures, including recruitment maneuvers and PEEP adjustments during routine mechanical ventilation. Physiological responses are assessed using repeated within-subject measurements obtained before, during, and after ventilator interventions.

Study Record Dates

• First Submitted: July 16, 2026
• First Posted: July 21, 2026
• Study Start: February 1, 2024
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): February 1, 2027
• Last Updated: July 21, 2026

Record last verified: 2026-07

Locations

CN (1)