Effect of different doses of dexmedetomidine on sevoflurane consumption in patients undergoing laparoscopic oophorocystectomy

Objective To investigate the effect of different doses of dexmedetomidine(Dex)on sevoflurane consumption in patients undergoing laparoscopic oophorocystectomy.Methods Eighty ASA Ⅰ or Ⅱ patients aged 25-50 yr with body mass index 18-25 kg/m2 undergoing laparoscopic oophorocystectomy were randomly divided into 4 groups (n =20): control group (group C),low dose Dex group(group DL),medium dose Dex group(group DM) and high dose Dex group(group DH).Normal saline 20 ml and Dex 0.3,0.6,0.9μg/kg was infused iv over 10 min at 10 min before skin incision in groups C,DL,DM and DH,respectively.End-tidal sevoflurane concentration (ETsev) was recorded before Dex administration(T1 ),skin incision(T2 ),immediately after pneumoperitoneum (T3 ),10 min of pneumoperitoneum(T4 ) and the end of surgery (T5 ).Duration of anesthesia,consumption of sevoflurane,emergence time,extubation time were recorded and restlessness at 10 min after extubation was also recorded.The concentrations of blood glucose and corticosteroid were measured by quickly by glucose analyzer and radio-immunity gefore anethesia induction (T0) and at T3,T4,T5 respectively.Results The consumption of sevoflurane per hour,ETsev at T2-5,concentrations of blood glucose and corticosteroid at T3-5 were decreased gradually in groups C,DL,DM and DH ( P ＜ 0.05).The emergence time and extubation time were shorter and the incidence of restlessness was lower in groups DL,DM and DH than in group C ( P ＜ 0.05 ).Conclusion Dexmedetomidine can reduce the consumption of sevoflurane in a dose-dependent manner in patients undergoing laparoscopic oophorocystectomy. Key words: Dexmedetomidine ;  Anesthetics, inhalation ;  Ovarian cysts ;  Laparoscopy