[Combined anesthesia (epidural-general) in thoracic surgery: the cardiocirculatory response to induction. Propofol vs midazolam plus alfentanil].

Thoracic epidural block may unpredictably blunt the physiological sympathetic response to anaesthetic agents and profound hypotension could result at induction time. The authors evaluate two different induction regimens in 16 patients scheduled for major thoracic surgery in order to assess which of them would produce less hemodynamic changes. After the institution of high thoracic epidural block (6 ml lidocaine-CO2 2% + epinephrine 1/200,000 level: th.2-3), patients were randomly allocated in two induction groups: P and M. Group P received 2 mg/kg of propofol over 30 seconds; group M received midazolam 0.2 mg/kg plus alfentanil 30 mcg/kg. In Both groups induction was followed by a significant drop in blood pressure (-18% in group M and -37% i group P. In P group the fall in blood pressure is more pronounced than M group (p < 0.05). Noteworthy in both groups cardiac frequency do not increase and in M group significantly lowers. In the authors view the midazolam plus alfentanil induction technique compare well with propofol alone and would recommend its use in poor risk patients.