... of these factors.■ WHO DEVELOPS AUTO- PEEP? Auto- PEEP is more common than previouslythought in critically ill, mechanically ventilat-ed patients. Unexpected auto- PEEP occurs inup to 35% of ... ofexpiratory flow, resulting in auto- PEEP.7,9However, auto- PEEP and dynamic hyper-inflation may also occur without any intrinsiclimitation on expiratory flow,10and auto- PEEP is not uncommon ... dynamic hyperinflationAlthough auto- PEEP and dynamic hyperinfla-tion are usually thought to be synonymous, auto- PEEP does not necessarily imply dynam-ic hyperinflation. Auto- PEEP may also occurwhen...