The purpose of this study is to compare the time required to reach an end-tidal oxygen (EtO2) value of 90% and the time until the Oxygen Reserve Index (ORI) drops below 0.55 during preoxygenation in sarcopenic and non-sarcopenic patients. The study aims to investigate the impact of sarcopenia on the oxygenation process.

Inclusion Criteria:

• Patients who agree to participate in the study.
• Patients scheduled for major abdominal oncologic surgery.

Exclusion Criteria:

• Patients with severe cardiopulmonary disease.
• Patients with walking disabilities.

80 patients who agreed to participate in the study and are scheduled for major abdominal oncological surgery will be included in the study.