BACKGROUND: The ideal sedative medication for use during regional anesthesia would provide for an easily titrable level of sedation, predictable amnesia, decreased anxiety, while providing for a rapid recovery with minimal side effects. We investigated the clinical effects produced by three different infusion regimens for propofol during regional anesthesia. METHODS: Thirty elderly male patients undergoing urologic surgery were randomly enrolled into three groups, who were receiving epidural anesthesia. In groups I-III, loading doses of propofol equal to 0.6, 0.8, or 1.0 mg/kg intravenously, respectively, were followed by fixed rate propofol infusions of 1.2, 1.6, or 2.0 mg/kg/hr, respectively. Sedation was assessed by a blinded observer using sedation score. Intraoperative amnesia was assessed using picture recall. RESULTS: Sedation scores increased in a dose-dependent fashion (2.5+/-0.5, 3.1+/- 0.5, and 3.9+/- 0.8 in groups I-III, respectively). Intraoperative amnesia was more commonly observed in the higher-dosage groups (30%, 20%, and 0% of patients in groups I-III, respectively). There was no significant changes in hemodynamic and respiratory variables. The degree of satisfaction in propofol sedation was rated as good on 90% of the patients. CONCLUSIONS: Propofol infusion during regional anesthesia was an effective sedative technique with rapid recovery, high degree of satisfaction and minimal side effects.