Effects of Mechanical Ventilation Guided by Transpulmonary Pressure on Gas Exchange During Robotic Surgery: a Pilot Study

Patients will receive volume controlled ventilation set with a tidal volume at 6-8 ml/kg of ideal body weight, an inspiratory transpulmonary pressure less than 20 cmH2O, and an expiratory transpulmonary pressure (PLexp) equal or greater than 0. At PLexp increasing from 0 up to 10 cmH2O, inspired fraction of oxygen would also be increased from 40% to 100%. Respiratory rate will be set to obtain an arterial partial pressure of carbon dioxide between 35 and 45 mmHg and to ensure a physiological pH. Whenever the clinician will deem it appropriate, an alveolar recruitment maneuver as previously described

13 patients will undergo volume controlled ventilation set with a tidal volume between 6-8 ml/kg of ideal body weight, positive end-expiratory pressure and fraction of inspired oxygen set to obtain a peripheral saturation in oxygen equal or greater than 94% and a plateau pressure \<28 cmH2O Respiratory rate will be set to obtain an arterial partial pressure of carbon dioxide between 35 and 45 mmHg and in any case to ensure a physiological pH. In addition, whenever the clinician will deem it appropriate, an alveolar recruitment maneuver will be performed as previously described