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

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.

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