Objective: The aim of the study was to compare the ventilatory effect between propofol deep sedation technique with and without midazolam in hepatic tumor patients undergoing radiofrequency ablation procedure. Methods: Three hundred and seventy-four patients who underwent radiofrequency ablation procedure in a single year were randomly assigned to the deep sedation without midazolam group (A, n = 187) and deep sedation with midazolam group (B, n = 187). Patients in group A received normal saline, and those in group B received 0.02 mg/kg of midazolam intravenously in equivalent volume. All patients were oxygenated with 100% O2
via nasal cannula and sedated with intravenous fentanyl and the titration of intravenous propofol. Ventilatory parameters, including oxygen saturation, end tidal carbon dioxide, and respiratory rate every five minutes, during and after the procedure, as well as the duration of sleep and sedation score in the recovery room, were recorded. Results: There were no significant differences in the patients’ characteristics, duration of procedure, total dose of propofol, ventilatory parameters including oxygen saturation, end tidal carbon dioxide, and respiratory rate, as well as sedation score at 20, 25, 30, 35, and 40 min after the procedure, between the two groups. However, mean sedation score at 5, 10, and 15 min after the procedure, in group B, was significantly lower than in group A. In addition, the duration of sleep after the procedure, in group B, was significantly greater than in group A. No serious ventilatory adverse effects were observed either group. Conclusion: Propofol deep sedation with and without midazolam for hepatic tumor patients who underwent radiofrequency ablation procedure was safe and effective. A low dose of midazolam in propofol deep-sedation technique did not create serious ventilatory effects.