Abstract: When patients have both intracranial hypertension and severe lung injury, Improper mechanical ventilation can lead to “lung brain mutual damage”. Because of the risk of intracranial hypertension caused by protective ventilation strategies adopted by acute respiratory distress syndrome patients, it is necessary to protect the lung and brain at the same time to prevent secondary brain damage by mechanical ventilation. Positive end-expiratory pressure, recruitment maneuvers and prone positioning may have effects on cerebral physiology of traumatic brain injury patients: they may negatively affect intracranial pressure, based on the cerebral perfusion pressure regulation(through changes in cardiac output, mean arterial pressure, venous return). Lung ultrasound(LUS)and brain ultrasound(BUS)have proven their potential in respectively monitoring lung aeration and brain physiology at the bedside. For those neurocritical patients who need mechanical ventilation, LUS and BUS can guide us to set ventilator parameters reasonably and realize brain-protective ventilation strategy.

Key words: acute respiratory distress syndrome, brain injury, lung ultrasound, brain ultrasound