In a healthy, young human adult, tidal volume is approximately 500 ml per inspiration at rest or 7 ml/kg of body mass.
Ventilator-induced lung injury such as Acute lung injury (ALI) /Acute Respiratory Distress Syndrome (ARDS) can be caused by ventilation with very large tidal volumes in normal lungs, as well as ventilation with moderate or small volumes in previously injured lungs, and research shows that the incidence of ALI increases with higher tidal volume settings in nonneurologically impaired patients.
[citation needed][clarification needed] Protective lung volumes apply 6ml/kg to 8ml/kg with a rate high enough for proper alveolar ventilation but does not create or aggravate intrinsic Positive End-Expiry Pressure (PEEP).
Permissive hypercapnia can be employed in an attempt to minimize aggressive ventilation leading to lung injury.
[clarification needed] Patient should be started on 6 ml/kg and PEEP increased until plateau pressure is 30 cm H20 in most severe cases.