Different Low-flow Sevoflurane Anesthesia Techniques

Comparison of the Consumption of Sevoflurane in Two Different Concentrations and Two Different Currents During the Initial Period of Anesthesia in Patients Undergoing General Anesthesia With Minimal Flow

After reaching 1 MAC level with 4 lt / min fresh gas flow and 2.5% sevoflurane concentration in the initial stage in 35 patients, anesthesia maintenance will be continued with 0.5 lt / min fresh gas flow and 2 -4% sevoflurane concentration with the target of 1 MAC. For 35 patients, after reaching 1 (MAC) level with 1 lt / min fresh gas flow and 8% sevoflurane concentration in the initial phase, maintenance of anesthesia will be continued with 0.5 lt / min fresh gas flow and 2 -4% sevoflurane concentration, targeting 1 MAC.

The primary aim of this study is to compare the instantaneous and total consumption of sevoflurane using 2 different concentrations and different minute / fresh gas flow to fill the system in the initial phase of anesthesia. Its secondary purpose is to compare the depth of anesthesia and hemodynamic parameters between the two groups.

A total of 70 patients between the ages of 18-65 will be included in the study.in 2.5 % sevoflurane grup After reaching 1 MAC level with 4 lt / min fresh gas flow and 2.5% sevoflurane concentration in the initial stage in 35 patients, anesthesia maintenance will be continued with 0.5 lt / min fresh gas flow and 2 -4% sevoflurane concentration with the target of 1 MAC. in sevoflurane 8 % group for 35 patients, after reaching 1 (MAC) level with 1 lt / min fresh gas flow and 8% sevoflurane concentration in the initial phase, maintenance of anesthesia will be continued with 0.5 lt / min fresh gas flow and 2 -4% sevoflurane concentration with the target of 1 MAC. . The depth of anesthesia for both groups will be measured by the Bispectral Index (BIS). BIS values between 40 and 60 are appropriate values for general anesthesia, for this value 1 MAC sevoflurane inhalation anesthesia and remifentanil infusion (0.1-0.3mcg / kg / min) will be used.

Inclusion Criteria:

• Patients between the ages of 18-65
• ASA1,2,3 group patients
• Patients under general anesthesia
• Patients scheduled for elective surgery

Exclusion Criteria:

• The patient's refusal to participate in the study
• Patients with less than 90 minutes of total anesthesia time
• Patients whose total anesthesia time exceeds 180 minutes