Positive pressure ventilation is a type of mechanical ventilation which works by increasing the pressure in the airway to deliver the oxygen to the respiratory system until the ventilator breath is finished. Finally, the pressure inside the air passage drops by natural elastic of lungs (passive exhalation). This type of ventilation was achieved by either using the invasive method (endotracheal intubation) or by non-invasive method (by using nasal or face mask). The concept and the design of Positive pressure ventilator was based on World war ll concept to provide the fighter pilots with high level of oxygen flying at such a high altitude. With the further discoveries of modern endotracheal tubes with high volume and low pressure cuff, this method was easily replaced the negative pressure ventilation.