Sedation for neuroradiology revisited: comparison of three techniques for cerebral angiography

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.

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.

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).

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.