Patients with dental phobia frequently require intravenous sedation to complete dental treatment. We encountered a case of a patient who received frequent sedation by propofol, which required escalation in the dosage of propofol required. The patient was a healthy young female with severe dental phobia, and the dental procedures were initiated under intravenous sedation. Intravenous sedation was administered to the patient more than 100 times over 9 years, and the dosages were analyzed. The mean dosage of propofol administered per hour was 6.9 ± 2.4 mg/kg/h, and the dosage tended to increase with frequency (0.06-0.1 mg/kg/h in each administration). Increased dosage was needed with a shorter interval between sedations after 30 episodes of sedation. Regarding the mean dosage of propofol per hour, the step-down method exhibited the highest increase in dosage rate of 0.18 mg/kg/h per administration followed by target-controlled infusion at 0.07 mg/kg/h per administration and combination sedation at 0.06 mg/kg/h per administration. We discuss factors that may be associated with acute tolerance to propofol when frequent propofol sedations are provided.
Keywords: Dental phobia; Dose escalation; Intravenous sedation; Propofol; Tolerance.