Predictive and intelligent control of sevoflurane closed circuit anesthesia
- VernacularTitle:预测控制加智能控制用于七氟醚闭合环路定量麻醉的可行性
- Author:
Fang ZHENG
;
Enyou LI
;
Jun LIU
- Publication Type:Journal Article
- Keywords:
Anesthesia, closed-circuit;
Drug therapy,computer-assisted;
Predictive control;
Sevoflurane
- From:
Chinese Journal of Anesthesiology
1994;0(03):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the efficacy of servo controlled sevoflurane closed-circuit anesthesia and the feasibility of the predictive and intelligent control.Methods One hundred and forty-three ASA Ⅰ-Ⅲ patients (90 males, 53 females) aged between 3-77 yrs undergoing elective surgery were studied. Anesthesia was induced with intravenous fentanyl 2-3 ?g ?kg-1 , midazolam 0.12 mg?kg-1 and vecuronium 0.1 mg?kg-1 . After tracheal intubation the tracheal tube was connected to the servo-controlled closed-circuit system composed of IBM computer, O2 mass flow controller and electrically controlled sevoflurane injection pump and multifunctional monitor. The fresh gas flow of O2 = [body weight (kg)3/4 ? 10 + 20] ml?min-1 . The end-expired sevoflurane concentration was maintained at 1.3 MAC by predictive and intelligent control.Results The average wash-in time to reach the target concentration was (5.2 ?2.4) min. The O2 flow rate was(0.22?0.04) L?min-1 . The cumulative uptake of sevoflurane was 5.16 ml, 7.74ml, 9.17ml, 11.08ml, 12.57ml, 13.00ml, 14.18ml, 15.60ml, 18.56ml and 24.6 ml at 30, 60, 90, 120, 150, 180, 210, 240, 300 and 420 min respectively. The uptake rate of fluid sevoflurane was equivalent to (0.2673e-0.0598t + 0.2269e-0.0597t + 0.1150e-0.002t) ml?min-1 . Conclusion The servo controlled sevoflurane closed-circuit system can effectively control the pre-set end-tidal sevoflurane concentration in spite of the influence of multiple factors and is safe and effective.
