The Effect of Order of Injection of Propofol and Remifentanil on Hemodynamic Changes during Induction of Anesthesia

One of the most common ways in intubation without muscle relaxant is using propofol and remifentanil. The common practice is injection of remifentanil and then propofol. This occasionally produces severe hemodynamic changes. The aim of this study is to inject propofol followed by remifentanil for evaluating the effect of the order of injection on decreasing these complications. 40 patients with American Society of Anesthesia (ASA) class I-II, who underwent minor elective surgery with airway mallampati class I-II entered the study. Patients were randomized into 2 groups each with 20 patients. The first group received 2.5mg/kg propofol followed by 1.5 g/mg remifentanil while the second group received 1.5 g/mg remifentanil followed by 2.5 mg/kg propofol. Laryngoscopy and hemodynamic changes were compared in two groups.Resutls: There was no difference between two groups in laryngoscopy attempts (P=0.145) but the frequency of easy laryngoscopy in the first group (85%) was more than the second group (60%) (P=0.031). Systolic blood pressure changes after laryngoscopy in the first group (20 7.7 mmHg) was less than the second group (28 6.7 mmHg) (P=0.001). There was no statistical significant difference between two groups in diastolic blood pressure and heart rate changes (P=0.88, P=0.86 respectively). Administrations of propofol before remifentanil during anesthesia induction produces acceptable hemodynamic changes in patients.