We know that respiratory functions of patients are affected under general anaesthesia. Although there are many underlying causes of ventilation-perfusion mismatch in the airways, the main cause is atelectasis during general anaesthesia.

Atelectasis occurs in almost all patients receiving general anaesthesia. The main cause of atelectasis is the loss of muscle tone during general anaesthesia. Postoperative atelectasis was described in the last century. It is defined as the closure of the alveoli due to a decrease in inspiratory force and collapse of the lung and the resulting loss of aeration.

Inhalation anaesthetics have been shown to cause hypoxic pulmonary vasoconstriction in studies. However, not all inhalation anaesthetics affect the airways in the same way.

In patients who will undergo surgical procedures under different general anaesthesia maintenance methods, conditions that disrupt the ventilation-perfusion balance in the lung peroperatively can be diagnosed and monitored early, easily and inexpensively by lung ultrasonography.

Lung ultrasound is a noninvasive, reliable, reliable, radiation-free imaging method that provides instantaneous imaging at the bedside. Lung ultrasound score is a scoring system that provides scoring of the loss of ventilation in the lung. For this purpose, it was aimed to divide both lung tissues into 12 areas and to give a score between 0 and 3 points and to show the severity of the loss of aeration according to the resulting total score.

Inclusion Criteria:

• 18-65 years old ASA I-II Surgical procedure time between 2 hours and 5 hours in supine position Patients who will undergo rhinoplasty, septorhinoplasty operation Patients whose consent was obtained with an informed consent form

Exclusion Criteria:

• Those with a history of malignant hyperthermia,
• People with alcohol or drug addiction,
• Presence of dementia or confusion,
• Uncooperative patients,
• Those with respiratory disease,
• Those with coronary artery disease, congestive heart failure,
• Patients with unstable blood pressure,
• Significant anaemia, liver or kidney disease,
• Women during pregnancy or lactation,
• Allergy to anaesthetic agents,
• Body mass index (BMI) >30 kg/m2,
• Those with sepsis or bacterial infection, Body temperature below 35°C and above 38°C at control value

18-65 years old, ASA I-II, who will undergo rhinoplasty, septorhinoplasty operation