Comparison of the effects of two anesthetic methods on MAC-awake of enflurane in patients undergoing mastectomy
- VernacularTitle:两种麻醉方法对乳腺癌根治术患者清醒时肺泡气安氟醚MAC的影响
- Author:
Li CHEN
;
Ying WANG
;
Fangwu LUO
- Publication Type:Journal Article
- Keywords:
Anesthesia, epidural;
Anesthesia, inhalation;
Breast neoplasms;
Mastectomy, radical;
Pulmonary alveoli;
Enflurane
- From:
Chinese Journal of Anesthesiology
1994;0(04):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To determine the awakening concentration of enflurane and evaluate the emergence from anesthesia in the presence and absence of epidural block. Methods Thirty ASA Ⅰ - Ⅱ female patients aged 35-65 yr undergoing elective radical mastectomy were randomly divided into general anesthesia group (GA, n = 15) and combined general-epidural anesthesia group (CGEA, n = 15) . The patients were premedicated with intramuscular atropine 0.01 mg? kg-1 30 min before operation. In CGEA group epidural block was performed at T3_4 before induction of general anesthesia. A catheter was inserted into the epidural space in a cephalad direction for 3-4 cm. A loading dose of 10-12 ml of 1.5% lidocaine was given after a test dose. During operation 1.5% lidocaine 5-6 ml was given via the catheter every 40-60 min. General anesthesia was induced with propofol 2.5 mg ? kg-1 and succinylcholine 2 mg ? kg-1 . The patients were intubated and mechanically ventilated (FiO2 = 100 % , FGF = 1.5 L ? min , VT = 8-10 ml? kg-1 ), Anesthesia was maintained with similar concentration of enflurane to ensure that the enflurane consumed during maintenance of anesthesia was similar in both groups. At the end of operation enflurane was maintained at 0.5 MAC for 15 min. The enflurane vaporizer was then turned off and enflurane was washed out with FGF 10 L?min-1 . The end-tidal enflurane concentration was recorded every 10 seconds and the patients were continually being asked to open their eyes. The end-tidal enflurane concentration at which the patients opened their eyes on request was recorded as MAC-awake and Steward score was evaluated (0 = deeply anesthetized, 6 = wide awake). Results MAC-awake of enflurane was 0.4% in GA group and 0.24% in CGEA group. Steward score was 4.8 in CGEA group and 4.2 in GA group. Conclusion Epidural block with lidocaine reduces the MAC-awake. Steward score is higher in CGEA group than that in GA group.
