This study will be performed in robotic assisted laparoscopic radical prostatectomy patients in Cerrahpasa Medical Faculty Monoblock Operating Room. Since robot-assisted laparoscopic radical prostatectomy is a surgical procedure which requires long-term mechanical ventilation, excessive trendelenburg position (30-45 °) and pneumoperitoneum; these interventions may lead to respiratory complications such as ventilation difficulty and aeration loss in patients. Nowadays, lung ultrasonography has been used in anesthesia practice and intensive care units in order to determine lung aeration loss. In this study, the investigators aimed to compare the possible aeration loss in lung parenchyma during pressure controlled ventilation and volume controlled ventilation which are frequently used in anesthesia practice in patients undergoing robotic radical prostatectomy.

Inclusion Criteria: 18-75 age

• Patient who will be undergo robot assisted laparoscopic prostatectomy surgery
• Patient with ASA (American Society of Anesthesiologists) Score 1-3

Exclusion Criteria:

• Patients with ASA Score above 3
• Patients with obstructive (FEV1<%60) or restrictive pulmonary disease (FVC<%60)
• Patients with intrathoracic operation history
• Heavy smokers (>25 cigarettes/day)

Since our study will be performed in patients with prostate cancer, all of our patients will be male.