Summary

Background and objective: The use of midazolam for conscious sedation is an accepted method of anxiety control in restorative dentistry. A lack of predictability in its effects requires the dose of midazolam to be adjusted to individual patient's requirements. We determined whether patient-controlled sedation was a suitable alternative to operator-controlled sedation in restorative dentistry.

Methods: A randomized crossover clinical trial involving 35 consecutive patients undergoing similar dental procedures. Patients were randomly given midazolam, administered either by the patient or by the operator at the first visit and the alternative option on the second visit. All patients were ASA I–II and their ages ranged between 20 and 48 yr. Blood pressure, heart rate, oxygen saturation and patient satisfaction were recorded.

Results: The onset time and initial dose for sedation were similar with the two methods of administration and the sedation scores and vital signs were satisfactory. In the patient-controlled group the mean total dose of midazolam was 7.9 (±4.2 SD) mg cf. 4.2 (±1.8 SD) mg in the operator-controlled group (P < 0.05). The time to fitness for discharge (15.4 (± 11.9 SD) min) was greater in the patient-controlled group cf. the operator-controlled group (8.5 (±9.5 SD) min), P < 0.05.

Conclusion: This study shows that patient-controlled sedation is a suitable alternative to operator-controlled sedation in the management of anxious dental patients.

Summary

Background and objective: Previous work in our department, prior to the advent of digital subtraction angiography, showed that anaesthetist-administered sedation for cerebral angiography using propofol infusion–bolus fentanyl resulted in significantly more patients with early recall than a bolus fentanyl and midazolam technique. Our present study reassessed, 10 yr after our original study, the effectiveness of sedation for neuroradiological digital subtraction cerebral angiography, using three techniques currently in use in the department.

Methods: A total of 88 adult patients were sedated for neuroradiological angiograms by one of three anaesthetist-administered regimens: propofol–alfentanil infusion; boluses of fentanyl with a propofol infusion and boluses of fentanyl and midazolam. The latter two regimens had been used in our previous sedation study. Patients were assessed for time to orientation at the completion of the procedure, and followed up the next day to determine their last memory before sedation, first memory after the angiogram and any recall of the procedure itself.

Results: All three techniques were found to give satisfactory sedation and showed minimal difference in the time to orientation at the end of the procedure (3.7, 4.3 and 5.1 min), any awareness of the procedure itself (20% of patients overall) and numbers of patients having early recall; that is, recall of still being in the radiology department before return to the ward (22/29, 16/29 and 20/30).

Conclusions: Our results show that since the introduction of digital subtraction angiography we may have a different end-point of sedation compared to our original study, as well as a shorter angiogram time. Satisfactory anaesthetist-administered sedation can be provided for cerebral angiography by either infusion or incremental techniques. We feel that the success and safety of a sedation technique depends considerably on the skill and experience of the administrator such that these sedation techniques are only suitable for safe use by an anaesthetist.

Summary

Background and objective: We conducted an open, prospective, randomized study to compare the efficacy, safety and recovery characteristics of remifentanil or propofol during monitored anaesthesia care in patients undergoing colonoscopy.

Methods: Forty patients were randomly assigned to receive either propofol (1 mg kg−1 followed by 10 mg kg−1 h−1, n = 20) or remifentanil (0.5 μg kg−1 followed by 0.2 μg kg−1 min−1, n = 20). The infusion rate was subsequently adapted to clinical needs.

Results: In the propofol group, arterial pressure and heart rate decreased significantly from the baseline. These variables remained unchanged in the remifentanil group, but hypoventilation occurred in 55% of patients. Early recovery was delayed in the propofol group (P < 0.002). Recovery of cognitive and psychomotor functions was faster in the remifentanil group. Fifteen minutes after anaesthesia, the Digit Symbol Substitution Test score was 28.6 ± 12.8 versus 36.2 ± 9.4 and the Trieger Dot Test score was 25.6 ± 8.1 versus 18.7 ± 4.1 in the propofol and remifentanil groups, respectively (both P < 0.05). Patient satisfaction, using a visual analogue scale, was higher in the propofol group (96 ± 7 versus 77 ± 21, P < 0.001).

Conclusions: Remifentanil proved efficient in reducing pain during colonoscopy. Emergence times were shorter and the recovery of cognitive function was faster with remifentanil compared with propofol. Remifentanil provided a smoother haemodynamic profile than propofol; however, the frequent occurrence of remifentanil-induced hypoventilation requires the cautious administration of this agent.