Incidence, characteristics and risk factors for alveolar recruitment maneuver-related hypotension in patients undergoing laparoscopic colorectal cancer resection

Figure 1 Flowchart of the study. Alveolar recruitment maneuver (ARM)-related hypotension means arterial pressure < 60 mmHg during an ARM or within 5 min after an ARM. ARM: Alveolar recruitment maneuver; OLS: Open lung strategy; PEEP: Positive end expiratory pressure; PROVOLON: PROtective Ventilation using Open Lung strategy or Not trial.

Figure 2 Alveolar recruitment maneuver-related hemodynamic changes and characteristics of alveolar recruitment maneuvers. A-D: Individual values (dots) and medians with interquartile ranges (line and error line) for the percentage decreases in mean arterial pressure (MAP) (A), systolic blood pressure (B), diastolic blood pressure (C), and heart rate (D); E and F: Mean (bar) and SD (error bar) of the duration of ARMs and the maximum tidal volume of ARMs. The blue bar indicates the pneumoperitoneum conditions, and the pink bar indicates the nonpneumoperitoneum conditions. ^aP < 0.05 vs ARM₁; ^bP < 0.05 vs ARM_last. Percentage decrease in MAP (%) = (MAP_pre-ARM - extreme value of MAP_{intra-ARM or post-ARM}) × 100/MAP_pre-ARM. An extreme value was defined as the highest value when a variable increased or as the lowest value when the variable decreased. ARM: Alveolar recruitment maneuver; post-ARM: Within 5 min after an ARM; ARM₁: The first RM; ARM_last: The last ARM; MAP: Mean arterial pressure; SBP: Systolic blood pressure; DBP: Diastolic blood pressure; HR: Heart rate; Vt_MAX: Maximum tidal volume.