The feasibility of using dexmedetomidine instead of propofol in anesthesia during adolescent scoliosis surgery

Objective To investigate the effect of dexmedetomidine instead of propofol on depth of anesthesia,wake-up test,anesthesia recovery and side effects during adolescent scoliosis surgery.Methods Sixty ASA Ⅰ or Ⅱ patients aged 10 y-25 y weighing 25 kg-64 kg scheduled for posterior spinal fusion surgery were randomly divided into two groups with 30 patients in each group:In group Ⅰ (dexmedetomidine group) dexmedetomidine was infused with loading dose of 1 μg/kg over 10 min followed by an infusion of 2.5 μg·kg-1·h-1,while in group Ⅱ (propofol group) propofol was started at 100 μg·kg1-min-1,and they are both adjusted to maintain a constant depth of anesthesia as measured by BIS of 40～50.In both groups cisatraurium infusion was started at 1 μg·kg-1·min-1 and titrated to maintain TOF at 50％; remifentanil was infused at 0.4 μg ·kg-1 ·min-1.MAP,CVP,HR,SpO2,PETCO2 and rectal temperature were continuously monitored during operation.Controlled hypotension was induced with nitroglycerin at 0.1 μg· kg-1· min-1～2 μg ·kg-1 ·min-1 and MAP was maintained at 60 mm Hg-70 mm Hg (1 mm Hg=0.133 kPa).After dissection through muscles cisatracurium infusion was stopped.Wake-up test was began after spinal correction.Wake-up time and extubation time were recorded.Ramsay scores and Riker scores during wake-up test and anesthesia recovery were also recorded.The consumption of dexmedetomidine,incidence of intraoperative awareness,vomiting and shivering were investigated.Results The Riker scores during wake-up test and anesthesia recovery in group Ⅰ [4.00(0.25) and 4.00(1.00)] was significantly lower than that of group Ⅱ[4.50 (1.00) and 4.00 (1.25)] (P＜0.05).There were no significant differences in Ramsay scores,wake-up time,extubation time,incidence of vomiting and shivering between the two groups.Dexmedetomidine consumption in group Ⅰ was (2.4±0.5) μg· kg-1· h-1,propofol consumption in group Ⅱ was (86±12) μg ·kg-1 ·min-1.No cases of intraoperative awareness was observed.Conclusions Instead of propofol,administering dexmedetomidine in conjunction with remifentanil and nitroglycerin in total intravenous anesthesia monitored by BIS during adolescent scoliosis surgery might provide sufficient sedative effect,raise the quality of wake-up test and anesthesia recovery,and has no adverse effects. Key words: Dexmedetomidine;  Propofol;  Scoliosis;  Wake-up test