Application Of Low Dose Of Norepinephrine Combined With Goal-directed Fluid Therapy In Patients With Intracranial Tumor

Objective: Patients undergoing intracranial tumor resection were infused with low dose of norepinephrine(NE)during anesthesia.The variation of cerebral oxygen metabolic parameters such as arteriovenous oxygen content difference(Ca-jvO2),cerebral oxygen extraction rate(CERO2),cerebral lactate production rate(LacPR)and other parameters were observed.The concentration of S100 B protein of internal jugular vein bulb blood was determined,and vital signs during surgery were recorded.The aim of the study was to investigate the effect of low dose of NE on patients with intracranial tumor resection receiving goal-directed fluid therapy.Methods: Forty ASAⅡ~Ⅲ adult patients of both sexes undergoing elective intracranial tumor resection were randomly divided into two groups with 20 in each using a random number table: the Group G(goal-directed fluid therapy)and the Group N(goal-directed fluid therapy with infusion of low dose of NE).All informed consents were obtained.The patients were without dysfunction of important organs,arrhythmia,peripheral blood vessel lesion and disturbance of blood coagulation.The Glasgow Coma Scale of each patient was 15.Electrocardiogram,noninvasive blood pressure,pulse blood oxygen saturation and temperature were continuously monitored in all patients.Peripheral venous pathways were established.After puncture of the left radial artery under local anesthesia,the FloTrac/Vigileo system was connected.The induction of anesthesia was conducted with midazolam 0.04mg/kg,propofol 2mg/kg,rocuronium 0.6mg/kg and sufentanil 0.5μg/kg.After endotracheal intubation,mechanical ventilation was performed by anesthesia machine.The tidal volume was set to be 8ml/kg.The end-tidal PCO2 was maintained between 30 mmHg and 40 mmHg.Right femoral vein and retrograde right internal jugular vein puncture were performed.Anesthesia was maintained with propofol at the rate of 3~6mg/(kg·h)and remifentanil at the rate of 0.1~0.3μg/(kg·min).In both groups,when stroke volume variation(SVV)was more than 13% for five minutes,it indicated that there was a lack of effective circulating blood volume and fluid bolus was needed to reduce SVV to below 13%.When SVV was below 13%,the fluid was transfused at a rate of 1~2 ml/(kg·h).In Group N,low dose of NE was infused at a rate of 0.01~0.03μg/(kg·min)after anesthesia induction while maintaining MAP above 65 mmHg.Red blood cells were transfused when the Hb was below 8g/dL.In both groups,arterial blood and internal jugular vein bulb blood were obtained for blood gas analysis after anesthesia induction(T1),when opening the dura mater(T2),1h after opening the dura mater(T3),at the end of surgery(T4),separately.Ca-jvO2,CERO2,LacPR and the ratio of cerebral blood flow to cerebral oxygen metabolic rate(CBF/CMRO2)were calculated.2ml venous blood was taken into a test tube.After standing and centrifuging,the concentration of S100 B protein of the serum was determined by ELISA.Also,the average volume of infused crystalloid and colloid solution,the total volume of transfusion,blood loss and urine volume were recorded and analyzed.Results:1 There were no significant differences between the two groups in sex,age,ASA classification,body mass index(BMI),and anesthesia time(P>0.05).2 At all time points,there were no significant differences of HR between the two groups(P>0.05).At T4 MAP was significantly higher in Group N than that in Group G(P<0.05).In Group G,there were no significant differences within the time points.In Group N,there was a significant increase in MAP at T4 compared with T1,T2 and T3(P<0.05).There was no statistical significance at remaining points.3 There were significant differences of total liquid intake and crystalloid solution intake between the two groups(P<0.05),separately.In Group N,both of them were lower than that in Group G.4 At all time points,there were no significant differences of Ca-jv O2 between the two groups(P>0.05).In Group G,there were significant decreases at T3 and T4 compared with T1(P<0.05).In Group N,there was a significant decrease at T2 compared with T1(P<0.05).There was no statistical significance at remaining points.5 There was a significant decrease of CERO2 in Group G than in Group N at T3 and T4(P<0.05).In Group G,there was a significant decrease at T4 compared with T1 and T2(P<0.05).In Group N,there was a significant increase at T3 compared with T2(P<0.05).There was no statistical significance at remaining points.6 There were no significant differences of LacPR at all time points(P>0.05).7 In Group G,there was a significant increase at T3 compared with T1(P<0.05).In Group N,there was a significant increase at T2 compared with T1(P<0.05).There was no statistical significance at remaining points.8 There were no significant differences of the concentration of S100 B protein between the two groups at all time points(P>0.05).In Group N,there was a significant decrease at T4 compared with T1(P<0.05).Conclusions: In patients with intracranial tumor resection receiving goal-directed fluid therapy,infusing low dose of norepinephrine continuously during anesthesia time can reduce the volume of infused liquid,maintain homeostasis,increase the perfusion of kidneys and increase urine volume.It can also maintain the stability of hemodynamic,improve cerebral blood flow and optimize the relationship of the delivering and using oxygen in the brain.