The study investigates the effects of induced pneumoperitoneum during surgery on ventilatory parameters including peak inspiratory pressure, lung compliance, end-tidal CO2 at specific time-points: after induction of anaesthesia, after induction of surgery, one-hour and two-hours during surgery, end of surgery.

The effects of pneumoperitoneum are compared between two groups of patients: patients undergoing laparoscopic surgery and patients undergoing robotic-assisted surgery. No intervention was performed in this study and the decision for type of surgery performed was made by the attending surgeon prior to study inclusion

Inclusion Criteria:

• patients who underwent video-assisted surgery by either classic laparoscopy or robotic-assisted surgery.

Exclusion Criteria:

• refusal to participate
• conversion of surgery to laparotomy
• need of vasopressure support
• preoperative severe respiratory dysfunction

consecutive patients undergoing video-assisted surgery in a university hospital after inclusion and exclusion criteria have been met. Video-assisted surgery is defined by either classic laparoscopic surgery or robotic assisted surgery and the medical decision between the two types of surgery was performed by the attending surgeon prior to patient inclusion (unrelated to the study).