Comparison of hemodynamic changes of Propofol and Thiopental during

Introduction: General anesthesia is the most common technique for performance of various surgical procedures. Thiopental is the most common anesthetic agent for intravenous induction. Since the introduction of propofol as an anesthetic agent, its use has increased progressively and has become the drug of choice for induction of anesthesia in several conditions. The aims of this study were comparison of hemodynamic changes of propofol and thiopental during induction of anesthesia and tracheal intubation and using propofol instead of thiopental for induction of anesthesia. Methods: In this double-blinded, randomized clinical trial study, 60 adult patients in ASA class I and II (candidates for elective operation under general anesthesia) were randomly divided in two equal groups (1. propofol, 2. thiopental). After baseline measurment of systolic and diastolic blood pressures and heart rate and giving similar premedication with morphine and midazolam, 1st group received propofol (2mg/kg) and 2nd group received thiopental (5mg/kg) for induction of anesthesia. Then systolic and diastolic blood pressures and heart rate of patients were measured in 4 different periods: after induction of anesthesia and before laryngoscopy and tracheal intubation, immediately after tracheal intubation, 3 and 5 minutes after tracheal intubation. Duration of laryngoscopy and tracheal intubation were also recorded in all patients. Data were collected and t-test statistical analysis was done. Results: The two groups were similar regarding age, sex, duration of laryngoscopy and baseline hemodynamic parameters. Baseline mean systolic and diastolic blood pressures and heart rate were also similar in both groups, but systolic and diastolic blood pressures and heart rate measured at times after induction of anesthesia and before laryngoscopy, immediately and 3 minutes after tracheal intubation were significantly lower in propofol than thiopental group (P<0.05). There were no significant differences between 2 groups at time 5 minutes after tracheal intubation. Conclusion: According to these findings, propofol can be an ideal substitution for thiopental as an induction agent due to stronger suppression of hemodynamic responses to larynfoscopy and intubation.