Cerebral protection of dexmedetomidine during craniotomy under general anesthesia in patients with craniocerebral injury / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the cerebral protection of dexmedetomidine during craniotomy under general anesthesia in the patients with craniocerebral injury.Methods Sixty patients with craniocerebral injury,aged 30-50 yr,with body mass index of 18-25 kg/m2,of ASA physical status Ⅱ or Ⅲ,with Glasgow Coma Scale score of 6-12,scheduled for elective craniotomy under general anesthesia,were randomized into 2 groups (n =30 each) using a random number tablecontrol group (group C) and dexmedetomidine group (group Dex).Anesthesia was induced with iv midazolam,propofol,cisatracurium and sufentanil.The patients were endotracheally intubated and mechanically ventilated.In group Dex,dexmedetomidine 1 μg/kg was infused intravenously over 10 min before induction of anesthesia,followed by infusion at a rate of 0.5 μg · kg-1 · h-1 until the end of operation.The equal volume of normal saline was given in group C.Immediately before beginning of surgery (T0),at the moment when the duramater was opened (T1),at 2 h after beginning of surgery (T2),at the duramater closing (T3) and at the end of surgery (T4),blood samples were obtained from the radial artery and jugular venous bulb for blood gas analysis,arteriovenous blood O2 difference and cerebral O2 extraction rate were calculated.The serum concentrations of S-100β were measured by ELISA.Results The serum concentrations of S-100β were significantly increased at T2-4 than at T0 in both groups.The serum concentrations of S-100β were significantly decreased at T2-4 in group Dex than in group C.The parameters of cerebral oxygen metabolism were all within the normal range in both groups.Conclusion Dexmedetomidine (1 μg/kg infused intravenously before induction of anesthesia,followed by infusion at a rate of 0.5 μg · kg-1 · h-1 until the end of operation) provides cerebral protection to some extent during craniotomy under general anesthesia in the patients with craniocerebral injury.