Airway

Bag-valve-mask tidal volume

Ventilation is a balance: enough volume to produce visible chest rise, not so much that you pressurize the chest. Each breath should move the chest without forcing the stomach to distend.

Excessive tidal volume raises intrathoracic pressure, impairs venous return, and can drop preload and blood pressure—especially in fragile or hypovolemic patients. If the abdomen balloons during BVM, reduce pressure and volume rather than increasing rate or oxygen concentration alone.