Randomized controlled trial comparing low inspiratory and expiratory flow during variable volume ventilation (VVV) with a constant volume decelerating flow (PCV pressure controlled volume guarantee) ventilation.~After anesthesia induction patients are VVV or PCV ventilated with a positive end expiratory pressure (PEEP) of 10 cm H2O. Average tidal volume is set at 6 ml/kg and end tidal CO2 is kept between 30 and 50 mmHg in both groups by adapting breaths per minute between 10 and 16. I/E ratio is set at 1/1 in VVV and at the standard ½ in PCV.~Dynamic lung compliance is measured before and during pneumoperitoneum. If dynamic lung compliance is less than 40 or decreases below 40 a first lung recruitment (10 sec of 30 up to 40 cmH2O) is given till dyn compliance rises above 40.~Dynamic lung compliance is further monitored and when value decreases again below 40, a new lung recruitment (LRM) is given and the PEEP is increased to 15 cm H2O after the second LRM.~All patients get an opioid free general anesthesia with anti inflammatory agents and deep NMB with full reversal at end of surgery.~The moment and number of LRM performed after induction of anesthesia with the averaged reached lung compliance is used to compare both ventilation methods.~The oxygen saturation without oxygen at arrival of PACU and the need for oxygen when saturation drops below 95 % are compared between both groups.
Randomized controlled trial comparing low inspiratory and expiratory flow during variable volume ventilation with a constant volume decelerating flow (pressure controlled volume guarantee) ventilation.