Evaluation of the Effects of Preoperative Breathing Exercises on Preoxygenation Period

Inclusion Criteria: * Patients who will undergo elective abdominal surgery under general anesthesia * Between the ages of 18-65 * Both genders * ASA I-III risk group * Patients who accept and give consent to participate in the study Exclusion Criteria: * Patients who did not agree to participate in the study * Patients younger than 18 years old and older than 65 years old * Patients with advanced heart failure * Conditions where the patient is uncooperative (e.g. dementia, Alzheimer's) * Patients who refuse to breathe through the mask before EtO2 reaches 85% or more after the preoxygenation process begins * Patients who cannot reach the EtO2 level of 85% within five minutes * Deeply Anemic Patients (Hb\<8 gr/dl) * Patients with neurological sequelae * Patients with conditions that may prevent effective preoxygenation (those with long beards, patients with a nasogastric tube, etc.)