Investigator aimed to assess blood level of sevoflurane and desflurane during two lung ventilation and one lung ventilation. The investigators will use Gas Chromatography for define drugs levels. 16 patients with ASA I-III patients who undergo thoracotomy and abdominal surgery will be recruited to this study. Patients will divided in to the 2 groups. %1.5 Sevoflurane will apply in Group S and %6 Desflurane will apply in Group D during anesthesia maintenance. Each groups will divide 2 subgroups which are one lung ventilation groups and two lung ventilation groups. Two lung ventilation will be performed to Group Sa and Group Da, one lung ventilation will be performed to Group Sb and Group Db. Sequential blood samples will be taken from both arterial and central venous canula at the same time point. First blood samples will be taken at 40. minutes of anesthesia. Sequential samples will be taken at interval of 10 minutes during two lung ventilation. In one lung ventilation second blood samples will be taken at the 10. minutes of one lung ventilation. After than at the interval of 10 minutes, collection of blood samples both arterial and central venous will be continue.~All collection will assess with gas chromatography.
16 patients with American Society of AnesthesioIogy (ASA) physical status I-III will recruited to this study. Patients will divided to the 2 groups. %1.5 Sevoflurane will apply in Group S and %6 Desflurane will apply in Group D. Each groups will divide 2 subgroups. Two lung ventilation will be performed to Group Sa and Group Da, one lung ventilation will be performed to Group Sb and Group Db. At the time point 40.minutes first blood sample will given from patients. Blood sample will be taken at intervals of 10 minutes from groups of two lung ventilation. In groups of one lung ventilation, blood samples will be taken at the time interval of 10 minutes after one lung ventilation started. All blood samples will be assess in Gas Chromatography.