Wash-in Period in Patients Undergoing Low Flow Anesthesia

Inclusion Criteria: * ASA I-II risk group patients Duration of surgery between 2 hours and 4 hours, cases with general anesthesia Exclusion Criteria: * Patient refusal to participate in the study * Under 18 years old BMI\>40 * Patients receiving invasive mechanical ventilator support in the last 1 month * Patients who have received chemotherapy or radiotherapy in the last 2 months * Those with severe lung disease (COPD, asthma, pulmonary infection, bronchiectasis, previous need for non-invasive mechanical ventilation, oxygen therapy or steroid therapy for acute attack) * Known severe pulmonary hypertension * Smoke poisoning (carbon monoxide, cyanide poisoning) * Alcohol or acetone poisoning * Malignant hyperthermia * Intracranial tumor * Hemodynamic instability * Shock * Neuromuscular disease * Pathologies causing increased intracranial and intraocular pressure * Those with severe cardiac arrhythmias Those with -EF\<30 * Severe peripheral arterial disease * Patients with liver and kidney dysfunction