CONTINUOUS I-V PROPOFOL ADMINISTRATION MONITORED BY COMPUTERIZED EEG IN ANESTHESIA AND INTENSIVE-CARE

Propofol was administered by i-v infusion for continuous sedation unde r the guidance of spectral edge frequency (SEF), in three different cl inical 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 t he initial bolus dose). The patients belonging to the last two groups were each randomized into two subgroups: one for whom the EEG screen w as visible to the anesthesiologist and the second where the anesthesio logist was blind thereto. The analysis of the results of the three stu dies showed that SEF could easily be kept within pre-established limit s 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 cardiovascul ar 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 propofo l dosage seems to assure a quicker recovery after stopping the infusio n but the data obtained so far were not statistically significant. Kee ping SEF in pre-determined limits demanded an increased activity both during combined spinal-general anesthesia and when the patient was sed ated postoperatively. This aspect has to be taken into consideration w hen calculating the cost/benefit ratio of the method.