Influence of Mechanical Ventilation on Brain Circulation and Function

Whatever the technique used for ventilatory support, positive pressure breathing (PPB) elevates intrathoracic pressure. Local circulations can be altered by different mechanisms acting all together or separately [1]. These mechanisms consist in: 1. a reduction in systemic arterial pressure (SAP); 2. an impairment of local venous return and an increase in venous pressure; 3. an intrinsic or extrinsic modification of local vasoactive status.