Fig. 1.
Calibrated and uncalibrated esophageal pressure. Data are presented as median (circles and parallelograms) and [25th, 75th percentile] (whiskers). Calibrated (solid circles) and uncalibrated (hollow circles) esophageal pressure at end-expiration; calibrated (solid parallelograms) and uncalibrated (hollow parallelograms) esophageal pressure at end-inspiration. *Indicates P value from Wilcoxon rank test, whereas †, §, and ‡ refer to P values from post hoc multiple comparison Dunn test. †Versus baseline: for expiratory uncalibrated esophageal pressure P < 0.001, for inspiratory calibrated esophageal pressure P < 0.001, and for expiratory calibrated esophageal pressure P = 0.014. §Versus baseline: P < 0.0001. ‡Versus pneumoperitoneum–Trendelenburg: for expiratory uncalibrated esophageal pressure P = 0.020; for inspiratory calibrated esophageal pressure P = 0.002; and for expiratory calibrated esophageal pressure P < 0.001. PEEP, positive end-expiratory pressure.