Contribution of Transthoracic and Transcranial Ultrasonography to the Titration of PEEP in Patients With ARDS and ABI

The Contribution of the Combination of Transthoracic and Transcranial Ultrasonography to the Titration of Positive End-expiratory Pressure in Patients With Acute Respiratory Distress Syndrome and Acute Brain Injury

The present study will investigate whether the combined use of lung and brain ultrasonography is useful in selecting the optimal positive end-expiratory pressure in mechanically ventilated critically ill patients with acute respiratory distress syndrome and acute brain injury, aiming at an individualized, brain-protective ventilation strategy.

Study Overview

• Status: Recruiting
• Conditions: Acute Brain Injury; Acute Respiratory Distress Syndrome (ARDS)
• Intervention / Treatment: Procedure: Stepwise Positive End-Expiratory Pressure (PEEP) Increase Protocol

Detailed Description

The present study aims to evaluate whether the combined use of lung ultrasonography and brain ultrasonography can assist in determining the optimal positive end-expiratory pressure (PEEP) in mechanically ventilated, critically ill patients with acute respiratory distress syndrome (ARDS) and acute brain injury (ABI). In patients with concomitant respiratory and neurological injury, selecting an appropriate PEEP level is particularly challenging, as strategies that improve lung aeration may simultaneously increase intracranial pressure or compromise cerebral hemodynamics.

Lung ultrasound will be used to assess aeration patterns and guide lung recruitment through the Lung Ultrasound Score (LUS), while transcranial Doppler ultrasonography will be used to evaluate cerebral blood flow and intracranial pressure surrogates, such as the pulsatility index. By integrating both assessments, the study seeks to identify a PEEP level that optimizes pulmonary function while minimizing adverse effects on cerebral physiology. The overarching goal is to develop an individualized, brain-protective ventilation strategy for patients with ARDS and ABI.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Theodoros Schizodimos, MD; Phone Number: +306973439717; Email: teoschizo@gmail.com
• Study Contact Backup: Name: Georgia Pitsiou, PhD; Email: gpitsiou@yahoo.gr

Study Locations

• Greece
  • Thessaloniki, Greece, 54248
    • Recruiting
    • George Papanikolaou General Hospital
    • Contact: Theodoros Schizodimos; Phone Number: +306973439717; Email: teoschizo@gmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age ≥ 18 years
• Severe acute brain injury (e.g., traumatic brain injury, subarachnoid hemorrhage, intracerebral hemorrhage, acute ischemic stroke)
• Development of ARDS (according to Berlin criteria) within the first 10 days of ICU admission

Exclusion Criteria:

• Severe chronic brain diseases
• Brain tumor or central nervous system (CNS) infection
• Severe chronic pulmonary or cardiovascular disease
• Severe coagulopathy
• Undergoing decompressive craniectomy
• Lack of invasive neuromonitoring
• Withdrawal of life-sustaining treatment
• Poor acoustic window in ultrasound

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Stepwise PEEP Elevation Protocol Arm; All participants with ARDS and ABI will undergo a protocolized stepwise increase of PEEP at four levels. Each participant will serve as their own control.

Procedure: Stepwise Positive End-Expiratory Pressure (PEEP) Increase Protocol; The intervention includes a stepwise increase in PEEP level from 5 to 8, 12 and 16 centimeter of water (cmH2O). After each PEEP level change, lung ultrasound and transcranial doppler will be performed, and the values of intracranial pressure (ICP) and brain oxygen partial pressure (PO2), as well as the mechanical ventilation parameters, will be recorded. Arterial blood gases will be taken 20 minutes later.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Difference in PEEP Levels Between Optimal PEEP (LUS-Guided) and Safe PEEP (TCD and Respiratory Mechanics-Guided)	Optimal PEEP is determined using the Lung Ultrasound Score (LUS; aeration score 0-36), while Safe PEEP is determined based on Transcranial Doppler (TCD) measurements (Pulsatility Index, mean flow velocity) and respiratory mechanics parameters (driving pressure, plateau pressure, compliance). The outcome represents the difference between Optimal PEEP and Safe PEEP expressed in cmH₂O. Unit of Measure: cmH₂O	From the start of the intervention until completion of the PEEP titration procedure, within approximately 120 minutes from intervention initiation.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation Between PEEP Difference and Clinical Outcomes	Correlation between the difference in PEEP levels (cmH₂O) and the following clinical outcomes: duration of mechanical ventilation, ICU length of stay, and ICU/hospital mortality. Unit of Measure: PEEP difference: cmH₂O, Duration of mechanical ventilation: days, ICU length of stay: days, ICU mortality: %, Hospital mortality: %	From the intervention until ICU discharge and hospital discharge, assessed up to 90 days

Collaborators and Investigators

• Sponsor: Theodoros Schizodimos
• Investigators: Principal Investigator: Theodoros Schizodimos, MD, 2nd Intensive Care Unit, George Papanikolaou General Hospital of Thessaloniki

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2025
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): July 1, 2027

Study Registration Dates

• First Submitted: November 14, 2025
• First Submitted That Met QC Criteria: November 21, 2025
• First Posted (Estimated): November 25, 2025

Study Record Updates

• Last Update Posted (Actual): December 31, 2025
• Last Update Submitted That Met QC Criteria: December 26, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Wounds and Injuries; Respiratory Tract Diseases; Lung Diseases; Respiration Disorders; Craniocerebral Trauma; Trauma, Nervous System; Respiratory Distress Syndrome; Brain Injuries; Therapeutics; Airway Management; Respiratory Therapy; Respiration, Artificial; Positive-Pressure Respiration
• Other Study ID Numbers: 10957

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