In pregnancy, cephalal shift of the diaphragm caused by the enlarged uterus reduces the functional residual capacity and may increase the closure volume and predispose the pregnant woman to airway closure, leading to atelectasis. The development of atelectasis due to dermatomes retained in spinal anesthesia and intraoperative supine position may increase further. Oxygen therapy to be applied may also lead to absorption atelectasis by causing hyperoxia. The aim of our study is to evaluate the effect of oxygen support on the lungs in cesarean section operations under spinal anesthesia by lung ultrasound score and oxygen reserve index.

Inclusion Criteria:

• 18-50 years old
• ASA I-II
• Patients scheduled for elective cesarean section under spinal anesthesia

Exclusion Criteria:

• alcohol or drug addiction, chronic obstructive pulmonary disease, cardiovascular disease, smokers anemia, liver or kidney disease, coagulation disorders allergic to anesthetic agents, sepsis or bacterial infection, body temperature is below 35°C and above 38°C Multiple pregnancy Preoperative hypoxemia SpO2<94% Diabetes mellitus Hypertension Placenta previa Premature rupture of membranes Intrauterine growth retardation Preeclampsia-eclampsia-fetal distress Polyhydramnios Morbid obesity BMI>45

parturients who underwent cesarean section under spinal anesthesia

parturients who underwent cesarean section under spinal anesthesia