Vive la résistance! The role of inspiratory resistance breathing on cerebral blood flow

•Inspiratory resistance breathing facilitates improvements in vital organ perfusion.•Inspiratory resistance increases tolerance to hemorrhage.•Inspiratory resistance can improve survival from cardiac arrest.•Inspiratory resistance increases arterial pressure in hypotensive patients. Prolonging the therapeutic window for treatment is imperative for survival from a multitude of life-threatening events such as hemorrhage, cardiac arrest, and stroke. Inspiratory resistance breathing is a therapeutic approach that augments the reduction in intrathoracic and intracranial pressure during inspiration, facilitating improvements in vital organ perfusion under conditions of ischemia, such as blood loss and cardiac arrest. In this review a series of studies will be presented assessing the role of inspiratory resistance breathing on responses of cerebral blood flow and cerebral tissue oxygenation under conditions of cardiac arrest and blood loss in animal models, and simulated hemorrhage in humans. Knowledge gaps in this field of investigation will be presented, and future research directions will be discussed.