Comparison Of Renal Function Impairment Induced By Inhalation Of Sevoflurane With Different Fresh Gas Flow

Objective:To investigate the effects of inhalation of sevoflurane under different gas flow on renal function impairment.Methods:This study was performed after receiving approval from the local ethics committee in our hospital and written informed consent from patients.From March2017 to June 2017,sixty patients who were scheduled for elective surgery（excepting urologic surgical procedures）were included in this prospective randomized study.Patients were randomly put into two equal groups as low-flow sevoflurane（L group）and high-flow sevoflurane anesthesia（H group）.No premedication was given to the patients.The patients taken into operation were monitored with elecrocardiogram,pulse oximetry,capnography,BIS,invasive blood pressure and central venous pressure measurement.Peripheral venous cannula was inserted and Lactated Ringer’s solution infusion was initiated.After 5-minute pre-oxygenation,the induction of anesthesia was performed with 0.04⁰.08mg/kg midazolam,0.4ug/kg sufentanil citrate,propofol 2².5mg/kg and 15⁰.3mg/kg cisatracurium.the patients inhaled 100%oxygen via a facial mask for 2 minutes and then intubated.After intubation,anesthesia was maintained with 3%Vol sevoflurane in the 100%oxygen of 4-5 L/min.After 10-15minutes,fresh gas flow was decreased to 0.5 L/min for low-flow group and 2 L/min for high-flow group,computerized infusion pump with remifentanil 0.1-0.2ug/kg/min、cisatracurium 0.1mg/kg/h and the expired concentrations of sevoflurane 1.3±0.1MAC were given for maintenance of anesthesia.Hemodynamic fluctuation without exceeding the baseline value of±20%was maintained by intermittently using small doses of propofol as needed.Ventilation variables were adjusted based on the tidal volume of8¹0ml/kg,and maintaining the end-tidal CO₂ value of 35⁴5mmHg.Sofnolime（coumpound:3%NaOH、12¹9%H₂O、>75%Ca（OH）₂）was used as CO₂ absorbent,and with new absorbent for each patient.Inhalation of sevoflurane was stopped 15²0min before the end of surgery.Venous blood samples were taken at the following time points respectively:immediately before anesthesia（T0）,1 hour after anesthesia（T1）,2 hours after anesthesia（T2）,3 hours after anesthesia（T3）,4 hours after anesthesia（T4）,the end of surgery（T5）and the 24^th（T6）,48^th（T7）and 72^th hour（T8）post operation.Sera of blood samples from time points of T0,T1,T2,T3,T4,T5 and T6 were taken for measurement of fluoride（F^-）,and from time points of T0,T5,T6,T7 and T8were taken for measurements of creatinine（Cr）,blood urea nitrogen（BUN）,cystatin C（Cys C）andβ2-microglobulin（β2-MG）concentration.Urine samples were taken at the time points of T0,T5,T6,T7 and T8 or measurements of urineβ2-MG concentrations.The comparisons of the serum fluoride,creatinine,urea nitrogen,cystatin C andβ2-microglobulin concentrations and urineβ2-microglobulin concentrations between L group and H group at the respectively different time points mentioned above,and among the several time points within L group or H group were performed.Results:No significant difference were found in gender,age,height,weight,ASA classification,operation site,operation time,anesthesia time,intraoperative urine output,intraoperative fluid infusion and vasoactive drug use between the two groups.There were no significant differences in serum F-between two groups at time point T0（P>0.05）;The serum F-in L group were significantly higher than those in H group at time points T1^T6（P<0.05）.In H group,there were no significant difference among time points of T5^T8 and T0 for serum Cr,BUN（P>0.05）;serum Cys C at time point T5was significantly higher than that of T0（P<0.05）;The levels of blood and urineβ2-MG at time points of T5 and T6 were significantly higher than those of T0（P<0.05）.In L group,the levels of serum Cr,BUN,blood and urineβ2-MG at time points T5 and T6 were significantly higher than those of T0（P<0.05）;The serum Cys C at time points T5^T7 were significantly higher than those of T0（P<0.05）.There was no significant difference between the two groups in serum Cr、BUN、Cys C、blood and urineβ2-MG at time point T0（P>0.05）.Serum Cr、BUN in L group were higher than those in H group at time point T5（P<0.05）;and there were no significant difference between the two groups at time points T6^T8（P>0.05）.Serum Cys C in L group at time points T5^T7 were significantly higher than those in H group（P<0.05）,there were no significant difference between two groups at time point T8（P>0.05）.The bloodβ2-MG in L group was significantly higher than that in H group at time point T5（P<0.05）;and there were no significant difference between two groups at time points T6^T8（P>0.05）.The urineβ2-MG in L group were significantly higher than those in H group at time pints T5^T6（P<0.05）;and there were no significant difference between the two groups at time points T7^T8（P>0.05）.Conclusion:Serum fluoride concentration increased as the prolongation of inhalation of sevoflurane,and the concentration in low-flow group was higher than that in high-flow group at all of the time points measured.There is no significance clinically renal function after inhalation anesthesia with sevoflurane.