The negative effects of pneumoperitoneum used in laparoscopic cholecystectomy on cerebral metabolism, intracranial pressure, cardiovascular (blood pressure, heart rate, venous return) and respiratory system are known.

Pneumoperitoneum formed with low (10 - 12 mmHg) intraabdominal pressure causes less fluctuations in hemodynamic and respiratory changes. Previous studies have shown that intraabdominal pressure increase is effective on cerebral metabolism, leading to increased intracranial pressure.

The aim of this study is to investigate the hemodynamic effects of two different pneumoperitoneum pressure ranges (10-12 mmHg and 13-15 mmHg) on cerebral oxygenation with using Near Infrared Spectroscopy (NIRS), which is is a non-invasive technique, in laparoscopic cholecystectomy surgeries.

The negative effects of pneumoperitoneum used in laparoscopic cholecystectomy on cerebral metabolism, intracranial pressure, cardiovascular (blood pressure, heart rate, venous return) and respiratory system are known.It is thought that pneumoperitoneum causes hemodynamic changes in the body by increasing blood catecholamine, vasopressin and norepinephrine levels.Sensitivity to these hemodynamic changes has been shown to be higher rate in patients with advanced age, morbid obesity, and increased intracranial pressure, and it is emphasized in studies that more attention should be paid to pneumoperitoneum pressures used in laparoscopic procedures with these groups.

In laparoscopic cholecystectomy surgery, pneumoperitoneum pressures used for surgical field visualization may differ.As a consequences, these different pressures have different haemodynamic and intracranial effects.Studies have shown that high intraabdominal pressure values cause more hemodynamic fluctuations than low intraabdominal pressure values.Systemic side effects have been shown to be lower in operations with low pneumoperitoneum pressure; In relation to the concept of multiple compartment syndrome, it is thought that the relationships between intraabdominal, intrathoracic and intracranial compartments, and changes in one compartment may affect other compartments and cause negative physiological and hemodynamic results.

There are studies in the literature on the hemodynamic effects of different pneumoperitoneum pressures.In our literature searches, we could not find any study comparing the effects of hemodynamic changes caused by two different pneumoperitoneum pressures, which can be classified as low and high, on cerebral oxygenation.We aimed to contribute to the literature by investigating the effects of different pneumoperitoneum pressure ranges on brain oxygenation.

Inclusion Criteria:

• American Society of Anaesthesiology (ASA) I-III,
• 18-65 years old
• under general anesthesia
• elective laparoscopic cholecystectomy

Exclusion Criteria:

• cerebrovascular diseases
• uncontrolled diabetes
• uncontrolled hypertension
• coagulopathy
• cirrhosis
• peritonitis
• asthma
• respiratory diseases such as chronic obstructive pulmonary disease (COPD)
• patients with morbid obesity
• multiple organ failure
• cases taken under emergency conditions
• cases returned to open cholecystectomy

Patients scheduled for elective laparoscopic cholecystectomy between February 2020 and September 2020 at Karadeniz Technical University Faculty of Medicine Farabi Hospital under specified conditions