This Study will aim to compare the effects of Pressure Controlled Ventilation - Volume Guarantee (PCV-VG) mode with volume control ventilation (VCV) and pressure control ventilation (PCV) modes on respiratory mechanics (including the dynamic compliance, PIP, mean airway pressure, driving pressure..etc) and oxygenation in pediatric laparoscopic surgery.

Laparoscopic surgery is superior to open surgery in terms of recovery time, less postoperative pain, less wound complications, shorter hospital stay, and earlier return to work. However, carbon dioxide insufflation causes several intraoperative cardiovascular, renal, and respiratory adverse effects. Regarding respiratory effects, elevated Intra-abdominal pressure and abdominal expansion shifts the diaphragm upwards. Thus, intrathoracic pressure increases, and expansion of the lungs is restricted. This is followed by a significant decrease up to 50% in pulmonary dynamic compliance and an increase in peak and plateau airway pressures. After deflation of pneumoperitoneum both the pulmonary compliance and airway pressures return to the baseline levels. High airway pressures and decreased compliance can be associated with pulmonary barotrauma, which may manifest as immediate pneumothorax. The basal lung regions are compressed during elevated IAP causing atelectasis and uneven ventilation-perfusion relationships, impairing gas exchange. Hence, the choice of ventilation mode is very important, especially in the paediatric population. Volume control ventilation (VCV) and pressure control ventilation (PCV) modes have been used but each has its own drawbacks, with the former risking increase in airway pressure when pulmonary compliance changes which can lead to barotrauma and the latter not guaranteeing the desired tidal volume which leads to hypoventilation that presents with hypercarbia. Pressure Control Ventilation - Volume Guarantee (PCV-VG) is a recent controlled ventilation mode that combines the benefits of both volume control ventilation (VCV) and pressure control ventilation (PCV) by delivering the preset tidal volume with a decelerating flow at the lowest possible peak inspiratory pressure during a preset inspiratory time and at a preset respiratory rate ensuring adequate ventilation .

Inclusion Criteria:

• ASA physical status I-II.
• Both sexes.
• Age: 1-8 years old.
• Scheduled for elective abdominal or urologic laparoscopic surgery.
• BMI between the 5th and 95th percentiles.

Exclusion Criteria:

• ASA physical status more than II.
• Pre-existing lung disease.
• Pre-operative chest infection.
• Any thoracic deformities.
• Unsatisfactory pre-operative arterial oxygen saturation or haemoglobin level.
• Patients with cardiac, hepatic, or renal diseases.
• BMI above and below the 95th and 5th percentile respectively.

Single blind