Carotis cFT In Prediction Of Hypotension

The FTc value of the patients to be included in the study will be measured by ultrasonography 10 minutes before the induction of anesthesia.After the measurement, the patients will be monitored with 3-lead electrocardiography, pulse oximetry and noninvasive blood pressure in the operating room. Before induction of general anesthesia, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MAP), oxygen saturation and heart rate will measured for 3 minutes at 1-minute intervals. Induction of anesthesia with 1-2 mg/kg propofol, muscle relaxation will be achieved with 0.6 mg/kg intravenous rocuronium. During mask ventilation, 1-2% concentration of sevoflurane and 50-50% oxygen-nitrous oxide will be used. After the anesthesia induction, SBP, DBP, MAP, oxygen saturation and heart rate will be measured for 3 minutes at 1-minute intervals. Hypotension; defined as a 30% reduction in SBP or a 20% reduction in MAP, or an absolute SBP below 90 mm Hg and MAP below 65 mm Hg within 3 minutes of induction of general anesthesia.Intravenous (iv) noradrenaline and/or iv crystalloid will be used in the treatment of hypotension.