Target-controlled Infusion Anesthesia and Post-induction Hypotension

Hemodynamic changes during induction of anesthesia may have adverse outcomes and should therefore be avoided. The decrease in blood pressure during induction of anesthesia with propofol is due to a decrease in systemic vascular resistance or cardiac output and may be increased by the concomitant use of other drugs such as remifentanil. Target controlled infusion (TCI) system aims to reach the theoretically targeted blood or brain concentration of anesthetic agents based on the patient's age, weight, and height, with computer-assisted algorithms. In manual anesthesia induction, anesthetic agents are administered at a fixed dose and rate adjusted according to the patient's weight, which may cause hypotension in patients with low cardiovascular performance. As target-controlled infusion (TCI) obviates the need to calculate the infusion rate manually, the use of TCI may provide a better hemodynamic profile during anesthesia induction This study was designed to test the hypothesis that propofol by TCI anesthesia induction is associated with a lower hypotension rate when compared with manual anesthesia induction

Inclusion Criteria:Patients with ASA( American Society Of Anesthesiology) physical status 1-3Underwent major elective surgeryRequired intra-arterial blood pressure monitoring before induction.Exclusion Criteria:Under 18 years of ageArrhythmia (atrial fibrillation, frequent premature beat)Severe valvular heart diseaseMorbid obesityIntubation difficultyDrug addictionTreatment with opiatesPregnancyEmergency surgery