Comparing the Effects of Remifentanil and Alfentanil on the Cardiovascular Responses to the Induction of Anesthesia and Tracheal Intubation in Elderly Patients

Abstract

Background and Objectives: Laryngoscopy and tracheal intubation could lead to hemodynamic responses in the form of hypertension and tachycardia as well as arrhythmia and myocardial ischemia. These alterations can be life-threatening particularly in elderly people. This clinical trial compared the effects of two rapid-onset narcotics, Alfentanil and Remifentanil, on the hemodynamic responses to the induction and tracheal intubation in elderly patients. Methods: This double-blind clinical trial was conducted on 40 subjects aged 65 and above. They were candidates of cataract surgery under general anesthesia. The patients were randomly allocated to two groups of 20. The first group, was given Alfentanil 10 mg/kg and for second group Remifentanil 0.5mg/kg was injected prior to the induction of anesthesia. Both groups were similiar in the method of anesthesia except in narcotics. The first group was infused with Alfentanil 1 mg/kg/min and Remifentanil 0.1 mg/kg/min was used for the second group. Hemodynamic variations including heart rate, systolic, diastolic and mean arterial blood pressure were measured and recorded eight times (before induction, aften injection, after intubation and five times during anesthesia). Data were analyzed with SPSS software using descriptive and analytical statistics such as T-test, Chi squre and ANOVA. Results: Immediately after injection of narcotic drugs, all hemodynamic variants decreased. Howerver, diastolic blood pressure in Remifentantil group was significantly more than Alfentanil group (P 0.05). Ephedrin was used to treat severe hypotention in those under Remifentanil (11 patients) more than those under Alfentanil (4 patients) (P< 0.05). Conclusions: According to the results of this study Remifentanil could prevent hemodynamic variation induced by laryngoscopy and treacheal intubation more than Alfentanil. However in some cases Remifentanil leads to hypotension during anesthesia. There is no important difference between two drugs in increasing heart rate after laryngoscopy and intubation