Propofol was administered by i-v infusion for continuous sedation under the guidance of spectral edge frequency (SEF), in three different clinical setups: during maintenance of general anesthesia (target SEF 8-12 Hz), as a supplement of epidural anesthesia (SEF 11-15 Hz) and as a sole agent for sedation after extensive abdominal aortic surgery (the SEF value being established according to each patient's response to the initial bolus dose). The patients belonging to the last two groups were each randomized into two subgroups: one for whom the EEG screen was visible to the anesthesiologist and the second where the anesthesiologist was blind thereto. The analysis of the results of the three studies showed that SEF could easily be kept within pre-established limits for most of the propofol i-v infusion time. The periods of time when SEF was kept in range were accompanied by a more evident cardiovascular stability, even in those cases for which the EEG screen was hidden to the team in charge of the patient. Using SEF as a guide for propofol dosage seems to assure a quicker recovery after stopping the infusion but the data obtained so far were not statistically significant. Keeping SEF in pre-determined limits demanded an increased activity both during combined spinal-general anesthesia and when the patient was sedated postoperatively. This aspect has to be taken into consideration when calculating the cost/benefit ratio of the method.
|Number of pages||10|
|Journal||Applied Cardiopulmonary Pathophysiology|
|State||Published - 25 Jun 1996|
- Spectral edge frequency