Figure 3.

Pao₂/Fio₂ ratio in different types of lung conditions at three PEEP levels. Patients in group N had normal lungs, those in group P had a primary lung disorder, and those in group S had a secondary lung disorder. Values are expressed as mean ± standard deviation. EELV, end-expiratory lung volume; FiO₂, inspired oxygen fraction; Pao₂, arterial oxygen tension; PBW, predicted body weight; PEEP, positive end-expiratory pressure.