Introduction: Intraoperative Mechanical Ventilation practices can lead to ventilator-associated lung injury (VILI) and postoperative pulmonary complications in healthy lungs. Mechanical Power has been developed as a new concept in reducing the risk of postoperative pulmonary complications as it takes into account all respiratory mechanics that cause VILI formation. Volume control mode is at the forefront in the old anesthesia devices used in the operating room, and today, together with technology, there are anesthesia devices with many modes and features, as in intensive care units. This causes confusion in the use of mechanical ventilators. In this study, volume and pressure control ventilation modes were compared in terms of respiratory mechanics (including mechanical power) in patients operated in the supine and prone positions.

Aim of study: It has been compared the effects on postoperative pulmonary complications (PPH) in terms of VILI risk by calculating mechanical power from advanced respiratory mechanics of patients ventilated in pressure and volume control modes, which are frequently used in operating room applications.

Conclusion: There was no statistically significant difference between the groups in terms of demographic data, ariscat score, and ariscat risk group values. The supine and prone mechanical power (MPrs) values of the volume control group were statistically significantly lower than the pressure control group. P values were calculated as 0.012 and 0.001, respectively.

Results: Supine and prone MPrs values of the volume control group were calculated significantly lower than the pressure control group. Pressure-controlled intraoperative mechanical ventilation is considered to be disadvantageous in terms of the risk of VILI in the supine and prone position in terms of the current mechanical power concept.

Although mechanical ventilation is a life-saving intervention, it can lead to ventilator-induced lung injury (VILI). VILI is the damage caused by positive pressure ventilation that starts with the use of mechanical ventilators. There are many factors that cause VILI such as tidal volume, drive pressure, flow, respiratory rate, and PEEP. Mechanical power, which collects these different variables in a single parameter, offers us new possibilities in predicting VILI at the bedside. The mechanical power being above a certain threshold causes damage ranging from pulmonary parenchymal rupture to severe inflammation and edema. Also, higher mechanical power values are associated with higher mortality. The protective ventilation strategy in intensive care units is also applied in operating rooms (OR) to minimize the risk of postoperative pulmonary complications due to VILI. While the volume control mode was at the forefront in the old anesthesia devices used in the OR, today there are anesthesia devices with many modes and features, as in intensive care units. This causes confusion in the use of mechanical ventilators in the perioperative period. Therefore, in this study, the investigators compared the perioperative mechanical power values in prone and supine positions, and postoperative pulmonary complications of two ventilation modes (volume control-pressure control ventilation). Thus, the investigators aimed to find out which ventilation mode would be advantageous in the perioperative period.

Inclusion Criteria:

• ASA I - III risk group patients
• Patients between the ages of 18-70
• At least 2 hours of mechanical ventilation time

Exclusion Criteria:

• Patients with COPD or Asthma bronchial
• Patients with a functional capacity of less than 7 METS
• Pregnant and lactating female patients.
• Patients who have had thoracic surgery before
• Patients with BMI above 35
• Patients who had hemodynamic instability or desaturation (SpO2<92%) during the operation

Cervical hernia, lumbar hernia and lumbar stabilization cases who were operated in the neurosurgery operating room of the anesthesia and reanimation clinic were examined.

Not decided yet.