All patients were received midazolam 2mg intravenously (IV) about five minute before induction. Anesthesia was induced with fentanyl( 1-3 mcgr/kg), propofol (2-3mg/kg), rocuronium (0,6 mg/kg). After intubation anesthesia was maintained with sevoflorane 2-3 % volume (to improve MAC 1 levels for sevoflorane). Remifentanyl was given continuously during surgery at a rate of 0.05-2 mcg/kg/min) (IV). Rocuronium was administered at a rate of 30 min time intervals during the anesthesia. Sugammadex was administered at the end of the surgery for reversing the neuromuscular blockage. Tramadol 1mg/kg, 40 mg meperidine and paracetamol 1g were administered for postoperative analgesia after trochars were removed. The concentration of volatile anesthetic was monitored with GE anesthesia machine. Patients were ventilated 6 lt/dk gas flow (50% oxygen with 50% air mixture). 6-8 ml/kg tidal volume, inspiration/ expiration rate 1/2 was maintained. Respiratory rate was 8-12 breaths. EtCO2 was kept within the range 35-45 mmHg. 5mmHg PEEP was administered in Group 5 PEEP, no PEEP was administered Group ZEEP. Fluid balance and blood replacement was maintained with %0.09 NaCl and ringer or colloid(Voluven Fresenius Kabi, Graz, Austria) solution IV. Body temperature was maintained normothermic by upper body forced air and warming pads. Laparoscopic pressure was maintained at below 14mmHg throughout the operation. Intraabdominal pressure was measured in mililitres of mercury through a Foley bladder catheter with 3 stopcocks connected to infusion set and pressure transducer. IT connected to the electronic monitor of anesthesia machine. (Datex -Ohmeda S/5 Compact, GE Healthcare, Finland) . After clemping the tube 100 ml Saline solution was injected in to the bladder. The transducer was replaced and zeroed to the urinary bladder level whenever the position changes throughout the procedure. Oscillation test was performed before started the IAP measurements. This measurements was performed into two position: basal, after induction, before insuflation, after insuflation, before desuflation, after desuflation values were measured in supine position; 30min, 45 min, 60min measurements in 30 degree reverse trendelenburg position (head of the bed elevated to 30 degree). Intraabdominal hypertension was defined as an IAP of 12 mmHg or higher, according to the consensus definations of the World Society for The Abdominal Compartment Syndrome.