The neuroprotective effect of dexmedetomidine during periopererative period in patients with meningioma

Abstract

Objective To evaluate the neuroprotective effect of dexmedetomidine (DEX) during perioperative period in patients with meningioma.Methods This was a prospective,double-blind,and placebo controlled study.Forty-five ASA Ⅱ-Ⅲ patients with meningioma aged 45 y-65 y weighing 55 kg-65 kg scheduled for elective intracranial tumor recection were enrolled and randomly divided into 3 groups(n=15):control group(group C);low-dose DEX group(group D1); high dose DEX group (group D2).DEX 1 μg/kg was infused i.v.10 min before anesthesia induction,and then was infused at a rate of 0.2 μg·kg1·h1(group D1)and 0.5 μg·kg-1 ·h-1 (group D2) until 30 min before the end of the operation.Group C received the equal volume of normal saline.Bispectral index (BIS) was maintained at 40-49.Venous blood samples were taken before intuction (T1),while the tumor was reresected (T2),extubation(T3),and 24 h after operation(T4) for determination of serum concentrations of S100β and neuron-specific enolase(NSE).Blood samples were also collected from radial artery and jugular venous bulb for blood gas analysis to calculate the cerebral extraction of O2 (CEO2).The changes of BP,HR during perioperative period were recorded.Results Compared with T1,the concentration of S100β and NSE in serum and CEO2 were significantly increased at T2-T4 in the three groups (P＜0.05).There was significant difference between group C and group D2 in the concentration of S100β and NSE in serum at T2-T4(P＜0.05).The numerical values of NSE in serum in group C were [(20.1±1.7),(26.5±2.9),(36.1±2.5) μg/L],while that of group D2 were [(13.9±2.3),(16.4±2.4),(20.0±2.9) μg/L],respectively at T2-T4.The numerical values of S100β in serum in group C were [(0.73±0.08),(0.86±0.08),(1.17±0.20) μg/L],while that of group D2 were [(0.65±0.05),(0.73±0.06),(0.896±0.051) μg/L],respectively at T2-T4.There was no significant difference in the indexes mentioned above between group C and group D1.There was significant diference in the three groups at T1-T3(P＜0.05).The numerical values of CEO2 in serum in group C were[(0.36±0.03),(0.34±0.03)],while that of group D1 were [(0.33±0.04),(0.30±0.04)],and group D2 were [(0.32±0.04),(0.26±0.04)],respectively at T2-T3.Conclusions Continuous infusing DEX intraoperative could decrease CEO2 and increase perioperative haemodynamic stability in patients undergoing meningioma surgery,exert neuroprotective effect.The protective mechanism may be related to the decline of the concentration of S100β,NSE in serum. Key words: Dexmedetomidine; Neuroprotection; Meningioma; Cerebral extraction of O2