Individual mean arterial pressure (MAP) and patients’ mean during intraoperative period in open surgery (A) and laparoscopic surgery (B). Baseline was recorded after intubation. Closed circles represent patients ventilating under positive end-expiratory pressure titrated by electrical impedance tomography (PEEP-EIT), and open circles represent patients ventilating under positive end-expiratory pressure (PEEP) of 4 cm H₂O. There was no difference between groups in both types of surgery.