Perioperative changes in ratio of arterial oxygen tension to fraction of inspired oxygen (left) and arterial carbon dioxide tension (right). Within group: *P < 0.0001; °P < 0.02. Vertical bars denote 95% confidence intervals. ANOVA: analysis of variance; ANR: awake non-resectional; NAR: non-awake resectional; PaO2/FiO2: arterial oxygen tension/fraction of inspired oxygen; postop: postoperative; preop: preoperative; QLM: quasilobar minimalist.