Fig. 1
Comparison of MV measurements in obese (Red, BMI ≥ 30) and non-obese (Blue, BMI < 30) patients at various points throughout their perioperative course. The measured MV in the obese population was significantly higher at every time point throughout the course: pre-operatively (Baseline, 9.7 ± 0.4 vs. 6.7 ± 0.3 L/min), beginning of surgery (6.0 ± 0.3 vs. 5.5 ± 0.2 L/min), during surgery (6.1 ± 0.2 vs. 5.3 ± 0.2), on arrival at the PACU (first 15 min: 11.4 ± 1.2 vs. 6.8 ± 0.7 L/min and second 15 min: 9.7 ± 0.8 vs. 6.2 ± 0.6 L/min) and at discharge (last 15 min: 7.7 ± 0.5 vs. 5.0 ± 0.6 L/min). These results are incongruent with IBW-based predicted MV (MVPRED) which were very similar (6.2 ± 0.2 vs. 6.1 ± 0.2 L/min, p = 0.37) and more closely aligned with BSA-based MVPRED (7.8 ± 0.2 vs. 6.9 ± 0.2 L/min, p = 0.0002)