OBJECTIVE: To observe the changes of auditory evoked potentials (AEP) index, mean arterial blood pressure (MAP) and heart rate (HR) undergoing desflurane anesthesia in the elderly and to evaluate the use of AEP index for monitoring the depth of desflurane anesthesia in the elderly. METHODS: Forty patients classified as ASA physical status I-III undergoing general anesthesia were divided into 2 groups with 20 patients in each group: Group elderly (> or =65 years) and Group youth (18-55 years). Anesthesia was induced with propofol and vecuronium. After the endotracheal intubation, the lungs were ventilated with desflurane in oxygen. End-tidal concentration of desflurane was maintained at 0.6 MAC, 1.0 MAC and 1.3 MAC for 20 min, respectively. The changes of MAP, HR and AEP index were recorded simultaneously. RESULTS: During the anesthesia of desflurane, MAP decreased significantly compared with those at preanesthesia in both groups. And HR decreased significantly compared with those at preanesthesia only in Group elderly (P < 0.05). The changes of MAP and HR had no statistical difference with increasing end-tidal desflurane concentration from 0.6 MAC to 1.3 MAC in both groups (P > 0.05). During the anesthesia of desflurane, AEP index decreased significantly compared with those at preanesthesia in both groups (P < 0.05). In the periods of increasing concentration of desflurane, AEP index decreased gradually. In Group elderly, AEP index decreased significantly 1.0 MAC and 1.3 MAC of desflurane compared with those of 0.6 MAC (P < 0.05). In Group youth, the changes of AEP index had no statistical difference with increasing end-tidal desflurane concentration from 0. 6 MAC to 1.3 MAC (P > 0.05). At the same concentration of desflurane, AEP index in the Group elderly were less than those in Group youth (P < 0.05). AEP index correlated with the end-tidal desflurane concentration significantly. The coefficient of product-moment correlation (r) were -0.983 and -0.980, respectively in Group elderly and Group youth (P < 0.05). CONCLUSION AEP index correlates well with the end-tidal desflurane concentration which is valuable for monitoring the depth of desflurane anesthesia in the elderly. AEP index can show the different depth of anesthesia at the same end-tidal desflurane concentration between the elderly and youth.
Aged ; Anesthetics, Inhalation ; Desflurane ; Evoked Potentials, Auditory ; Female ; Humans ; Isoflurane ; analogs & derivatives ; Male ; Monitoring, Intraoperative ; methods

Human ; Aged ; Middle Aged ; Adult ; Young Adult ; ADULT, ANESTHESIA ; ANESTHETICS ; SURGERY ; DESFLURANE ; MIDAZOLAM ; SEVOFLURANE ;

Adult ; Anesthetics, Inhalation ; administration & dosage ; Desflurane ; Electroencephalography ; methods ; Female ; Humans ; Isoflurane ; administration & dosage ; analogs & derivatives ; Male ; Middle Aged ; Monitoring, Intraoperative ; Nitrous Oxide ; administration & dosage

OBJECTIVE: To evaluate the values of bispectral index (BIS) in mornitoring the depth of desflurane anesthesia in the elderly by observing the changes of BIS at various end-tidal desflurane concentrations. METHODS: BIS was used to monitor the depth of desflurane anesthesia in the elderly without surgery stimulation. Forty ASA physical status I approximately III patients undergoing general anesthesia were divided into 2 groups with 20 in each group:Group Elderly ( > or =65 years) and Group Youth ( 18 approximately 55 years). Anesthesia was induced with propofol 2. 0 mg/kg and vecuronium 0. 1 mg/kg including the endotracheal topical anesthesia with 2% lidocaine. After the desflurane in oxygen, each concentration of desflurane was maintained for 20 minutes. The changes of mean arterial blood pressure (MAP), heart rate (HR) and BIS were recorded simultaneously. The timepoints setting for observation were: preanesthesia, 2 minutes after the anesthesia, endotracheal intubation, 2 minutes after the intubation, and end-tidal concentration of desflurane at 0. 6 MAC, 1.0 MAC and 1. 3 MAC. RESULTS: During anesthesia of desflurane, MAP and HR did not change significantly in the 2 groups with increasing end-tidal desflurane concentration from 0. 6 MAC to 1. 3 MAC (P > 0.05). BIS decreased significantly than that at preanesthesia in the 2 groups during anesthesia of desflurane ( P < 0.05 ). The changes of BIS were different in the 2 groups during the whole anesthesia (P < 0.05). As the concentration of desflurane increased, BIS decreased gradually but there were no significant changes on BIS in the 2 groups ( P > 0. 05 ). In general, BIS highly correlated with the end-tidal desflurane concentration. The coefficient of product-moment correlation (r) between BIS and the end-tidal desflurane concentration was -0. 996 and -0. 946 in Group Elderly and Youth (P < 0. 05 ). CONCLUSION BIS highly correlates with the end-tidal desflurane concentration which is used to evaluate the depth of desflurane anesthesia in the elderly and youth. There is different depth of anesthesia by BIS in the elderly or youth at the same end-tidal desflurane concentration.
Age Factors ; Aged ; Anesthetics, Inhalation ; Desflurane ; Dose-Response Relationship, Drug ; Electroencephalography ; drug effects ; methods ; Female ; Humans ; Isoflurane ; analogs & derivatives ; Male ; Monitoring, Intraoperative ; methods