Clinical Study Of The Monitoring Of EEG Non-linear Analysis

Part I: The application of EEG non-linear analysisunder anaesthesia of propofol with target-concentrationObjective To study the brain distribution of propofol sedation with target- concentration anesthesia. Methods 40 patients undergoing expected abdomen and limb operations were randomly divided into Propofol 3ug/ml group (A) and 4ug/ml group (B), each group had 20 cases. The combined intravenous anesthesia used propofol with target-concentration. The perioperative EEG non-linear parameter and perioperative EEG non-linear topographic Map of Approximate Entropy were recorded. BP, HR, SpO2 were recorded as usually Results The non-linear parameters were decreased at all brain areas with the propofol sedation. Comparing to pre-operation No significant differences were found between the two groups. Under combined intravenous propofol of target-concentration anaesthesia, the brain area restrain sequence of propofol were from frontal area and parietal area to temporal area and occipital area. The clearance sequence of propofol were from occipital area and temporal area to frontal area and parietal area. Conclusion Under intravenous combined propofol anaesthesia,the brain areas restrain of propofol was different. At inducement, the restrain began from frontal area and parietal area to temporal and occipital area. At anabiosis, the excitation began from occipital area and temporal area to frontal area and parietal area. Within propofol 3ug/ml group and propofol 4ug/ml group , under EEG no-liner analysis, the brain areas restrain of propofol wasn't different notably. Part II: The influmence of changes of carbon dioxidepressure of end-tidal on the EEG no-linear parametersduring the anesthesiaObjective: To study the influmence of changes of carbon dioxide pressure at the end of expiration on the no-linear parameters during the anesthesia. Methods: to choose randomly 15 patients undergoing expected abdomen and limb operations . The combined intravenous anesthesia used propofol with target-concentration. The carbon dioxide pressure of end-tidal of every patient was adjusted to three levels, (25±2)mmHg, (35±2)mmHg and(45±2)mmHg, every level lasted fifteen minutes. The EEG non-linear parameters of Approximate entropy; Correlation Dimension; Complexity were recorded at the every level. BP, HR, SpO2 and PetCO2 were recorded as usually. Results: The cardon dioxide pressure of end-tidal was different significantly, the EEG non-linear parameters of ApEn,D2 changed significantly , but the change of Cx was little. Conclusion: The variation of PetCO2 during the operation between the 25-45 mmHg produce significant changes in qEEG, result in the degree of anaesthsia make significant change in the EEG non-linear parameters.