[The target plasma concentration of propofol required to induce electroencephalography burst suppression with target-controlled infusion].

Objective: To determine the optimal target plasma concentration of propofol required to induce EEG burst suppression administered by TCI in order to decrease cerebral metabolic rate and increase tolerance to cerebral ischemia and hypoxia.
Methods: One hundred and fifty ASA I-II patients(aged 18-55 years-old, BMI < 30, Mallampati Score I-II) scheduled for elective surgery undergoing general anesthesia were enrolled in this study. Patients with systemic diseases or other factors effecting the electrical activity of brain were excluded. ECG, IBP, SpO2, PetCO2, Temperature and EEG (two-channel referential montage system) were continuously monitored during the procedure. Patients were induced with TCI propofol (the target plasma concentration was initially set at 5.4 microg/ml), After induction and intubation, target plasma concentration was increased by 0.3 microg/ml increment and sustained 15 minutes until EEG burst suppression appeared(stable burst suppression waveform and BSR > 50%), and this target concentration was recorded.
Results: The mean target plasma concentration of propofol with TCI required to induce EEG burst suppression was 6.1 +/- 0.6 microg/ml with 95% confidence interval of 5.99-6.19 microg/ml. There was no significant difference between the genders.
Conclusions: The target plasma concentration of propofol reached 6.2 microg/ml can induce EEG burst suppression, which is better for intraoperative cerebral protection.