The significant variation in TV per kg IBW as well as in PEEP values at our institution may reflect the lack of well-established guidelines for intraoperative ventilation. Many patients in this study received inappropriately large TVs (>8 mL/kg IBW), which may be due to calculation of TVs based on total body weight rather than IBW. Patients of shorter stature and higher body mass index appear to be at higher risk for ventilation with inappropriately large TVs.