Detecting possible atelectasis and other respiratory problems that may develop immediately after extubation via lung ultrasonography can reduce pulmonary complications by performing necessary interventions such as oxygen support, respiratory exercises, mobilization, and non-invasive mechanical ventilation applications at an early stage. In addition, although low-flow anesthesia is frequently used in daily anesthesia practice, publications showing the effects of its use in laparoscopic cholecystectomy operations on pulmonary complications are limited. On this occasion, this study can be presented as a contribution to the literature.

Postoperative atelectasis is a common complication that can develop in all patients receiving general anesthesia. The frequency of atelectasis increases due to increased intraabdominal pressure, especially in laparoscopic surgeries performed with pneumoperitoneum. For this reason, in order to prevent postoperative complications related to the lungs, it is extremely important to recognize atelectasis at an early stage, as well as to recognize the mechanisms that will cause atelectasis and avoid them.

Lung ultrasonography (Lung USG) draws attention for the rapid, cheap, safe and reliable detection of postoperative atelectasis. The fact that it can be applied at the bedside and can be easily repeated makes this method valuable. In the literature and in daily practice, it is seen that anesthesiologists commonly apply inhalation anesthesia with different fresh gas flow (FGF) rates during general anesthesia.

As defined by Baker and Simionescu, in low-flow anesthesia, FGF varies between 0.5 and 1 liter per minute. It has been shown that all types of flow are safe with modern anesthesia machines.

This study aims to demonstrate the effect of low-flow anesthesia (LFA) on pulmonary complications and, in particular, atelectasis that may develop after laparoscopic cholecystectomy operations, using a non-invasive, rapidly applicable, and proven method such as Lung USG.

Inclusion Criteria:

• Patients with informed consent
• Patients scheduled for laparoscopic cholecystectomy
• Patients with a Body Mass Index between 18-35 kg/m²
• Patients in the American Society of Anesthesiologist (ASA) 1-2-3 category

Exclusion Criteria:

• Patients with emergency surgery planned
• Patients with ASA 4 and above
• Patients with lung disease
• Patients who have undergone thoracic surgery
• Pregnancy
• Patients with a preoperative Lung Ultrasound Score of 2 or 3 in any lung region

All cases that meet the inclusion and exclusion criteria will be included in the study. Patients will be taken to the operating room after being preoperatively evaluated in the observation room. The patient's anesthetic management will be provided by another anesthesiologist who is not participating in the study and is responsible for the patient. Intraoperative data will be obtained from the patient's anesthesia follow-up form and the records of the anesthesia machine. When the patients arrive in the recovery room, postoperative ultrasonographic measurements and other evaluations will be performed and noted. This group will include patients who received general anesthesia using low-flow techniques during the intraoperative period.