<unk>  is a type of mechanical<unk>  that employs very<unk>  respiratory rates (>150 breaths per minute) and very small tidal volumes (usually below anatomical dead space). The primary goal of<unk>  is to achieve<unk>  and oxygenation at a reduced risk of ventilator induced lung injury (VILI). This is commonly referred to as lung protective<unk> .
Ventilator induced lung injury is caused by multiple factors. The human lung is designed to ventilate effectively by using negative pressure in the thorax. Once positive pressure is applied, some degree of VILI is likely to occur.
One major causative factor is the over stretching of the airways and alveoli. During mechanical<unk> , the flow of gas into the lung will take the path of least resistance. Areas of the lung that are collapsed (atelectasis) or filled with secretions will be under inflated, while those areas that are relatively normal will be over inflated. These areas will become over distended and injured. This may be reduced by using smaller tidal volumes.
During positive pressure<unk> , atelectatic regions will inflate, however the alveoli will be unstable and will collapse during the expiratory phase of the breath. This repeated alveolar collapse and expansion (RACE) will cause VILI. By opening the lung and keeping the lung open RACE (and VILI) is reduced.
High frequency ventilation
Positive pressure ventilation
Positive airway pressure
Mechanical ventilation
Biphasic positive airway pressure
Artificial respiration
Positive end-expiratory pressure
Oxygen therapy