Effects of esmolol combined with remifentanil on *MAC of isoflurane in patients undergoing upper-abdominal operation
- VernacularTitle:艾司洛尔复合瑞芬太尼对上腹部手术患者异氟醚MAC的影响
- Author:
Yanling ZHANG
;
Yanping CHEN
;
Dequan CAO
- Publication Type:Journal Article
- Keywords:
Propanolamines;
Piperidines;
Isoflurane;
Dose-response relationship,drug
- From:
Chinese Journal of Anesthesiology
2008;28(8):701-703
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the effects of esmolol and remifentanil on minimum alveolar concentration (MAC) of isoflurane in patients undergoing upper abdominal surgery. Methods One hundred ASAⅠorⅡpatients aged 18-60 yr undergoing upper abdominal surgery under general anesthesia were randomly divided into 5 groups (n=20 each):group A isoflurane alone; group B isoflurane + large dose esmolol; group C isoflurane + remifentanil; group D isoflurane + remifentanil + small dose esmolol and group E isoflurane + remifentanil + large dose esmolol. In group B and E esmolol was infused at 250 μg·kg-1·min-1 after a loading dose of 1 mg/kg (large dose esmolol). In group D esmolol was infused at 50 μg'kg-1·min-1 after a loading dose of 0.5 mg/kg (small dose esmolol). In group C, D and E remifentanil was infused at 0.05 μg·kg-1·min-1 after a loading dose of 0.25 μg/kg. As soon as the patients lost consciousness, tracheal intubation was facilitated with succinyl choline 1.5 mg/kg. The patients were mechanically ventilated (VT=8 ml/kg, RR 12 bpm, FiO2= 100% ). PET CO2 was maintained at 32-38 mm Hg and naso-pharyngeal temperature above 35.5℃. End-tidal isoflurane concentration was continuously monitored. If the patient moved his/her hand, foot, head or body within 60 seconds after skin incision was made the end-tidal isoflurane concentration was increased by 10% in the next patient; if the patient did not respond to skin incision the end-tidal concentration of isoflurane was decreased by 10% in the next patient. The initial end-tidal isoflurane concentration was 1.24% in group A and B, 0.78% in group C, D and E. Results The MAC of isoflurane was 1.24% ± O.14%, 1.22%±0.09%, 0.77%± 0.05%, 0.75% ±0.06%, 0.60%±0.05% in group A, B, C, D, E respectively. Remifentanil significantly reduced MAC of isoflurane in group C, D and E as compared with group A. The MAC of isoflurane was significantly lower in group E than in group C. Conclusion Remifentanil infusion at 0.05 μg·kg-1·min-1 combined with large dose esmolol can reduce MAC of isdlurane by 52% in patients undergoing upper abdominal surgery.
