| The object of this study is to use Narcotrend(NT)as the feedback index of target-controlled infusion of propofol,to optimize the closed-loop system to achieve NT-guided propofol automatic closed-loop target-controlled infusion,and to verify its feasibility,safety and reliability.There were 160 patients,97 males and 63 females,aged 18-70 years,ASA?~?,which were randomly divided into closed-loop target-controlled infusion(CLTCI group,n=78)and open-loop target-controlled infusion(OLTCI group,n=77).In the CLTCI group,anesthesiologists set up target Narcotrend index(NTI)value before the anesthesia induction,TCI pump according to the fluctuations of NTI automatically adjust the plasma target concentration of propofol to maintain NTI between 28 to 38 during anesthesia induction and maintenance.In the OLTCI group,anesthesia induction and maintenance used NT as a reference index,the propofol initial plasma target concentration was 5.5ug/ml,anesthesiologists according to their own clinical experience manually adjust the plasma target concentration of propofol to maintain NTI between 28 to 38.At the beginning of anesthesia induction,propofol target-controlled pathway was initiated in two groups.When the consciousness disappears,TOF mode was used to stimulate the ulnar nerve to calibrate the muscle and closed-loop infusion of cisatracurium was set up.Sufentanil 0.3~0.5ug/kg intravenous injection.Tracheal intubation was performed when NTI?46 and muscle monitoring T1 disappeared.The patients were mechanical ventilated after intubation(VT 8ml/kg,RR 10~16bpm/min,I:E 1:2).While monitoring PETCO2,according to arterial blood gas and PETCO2 to adjust the respiratory parameters,to maintain PaCO2 in 35~45mmHg.Both groups were with propofol and remifentanil target-controlled infusion during anesthesia maintenance.The target concentration of remifentanil was adjusted manually according to the clinical experience of anesthesiologist.The adjustment range was 4~8ng/ml.The feedback condition of closed-loop muscle relaxant injection system was counted 2,the maintenance rate was 0.02mg·kg-1·h-1 and the drug speed was 0.5mg·kg-1·h-1.Two groups of anesthesia were treated with total intravenous anesthesia.The induction period was defined as the time from the start of propofol to NTI?46 for 15 seconds and complete endotracheal intubation and the maintenance period from this point to the end of propofol and remifentanil administration.All the patients monitored BP,HR,ECG,PETCO2,Narcotrend,CVP,ABP and arterial blood gas.NTI,Mean arterial pressure(MAP)and heart rate(HR)were recorded at quiet time before anesthesia(t0),unconsciousness(t1),endotracheal intubation(t2),1 minute after intubation(t3),1 minute before skin incision(t4),skin incision(t5),intraoperative exploration(t6)and time of close peritoneum(t7).Monitoring arterial blood gas at t0,t4~t6.While the radial arterial blood was collected for 3ml.After centrifugation at room temperature,the plasma was placed in an EP tube and stored at-20?.The plasma concentration of propofol was determined by high performance liquid chromatography.Record the anesthesia time,opening eyes time,extubation time and calculated the use of propofol,remifentanil and vasoactive drugs.Postoperative follow-up records the incidence rate of adverse events such as nausea,vomiting,shivering and intraoperative awareness.Detailed data on TCI pump infusion after surgery and statistics on the adjusted frequency of TCI,the evaluation system indexes and the percentage of adequate anesthesia(NTI between 20 and 46),overshoot(NTI<20)and undershoot(NTI>46)periods.The evaluation system indexes included Global score(GS),Wobble,the median absolute performance error(MDAPE).Experimental results:1.Comparison of changes in MAP,HR:Comparison within the group: Compared with t0,the MAP of two groups was lower at t1 ~ t7(P <0.05).Compared with t0,the HR of two groups was lower at t1,t2,t4 ~ t7(P<0.05).There was no significant difference obsreved in HR between t0 and t3(P>0.05).Comparison between groups: Compared with CLTCI group,the MAP of t3,t6 in OLTCI group was significantly higher(P<0.05),and was lower in the t4 time(P<0.05).The HR of t2 and t3 in OLTCI group was significantly higher than that in CLTCI group(P<0.05).There was no significant difference between the two groups at the other time points(P>0.05).2.Comparison of changes in NTI:2.1 Comparison between groups: The NTI at t2 and t3 in OLTCI group was significantly higher than that in CLTCI group(P<0.05),and the NTI of t4 and t5 was lower than that in CLTCI group(P<0.05).There was no significant difference between the two groups at the other time points(P>0.05).2.2 Comparison of anesthesia depth during anesthesia induction and maintenance:Anesthesia induction period:There was no significant difference in the induction time and the duration of NTI<20 within 3 minutes after the induction between the two groups during the anesthesia induction period(P>0.05).The duration of NTI>46 within 3 minutes after the induction in the CLTCI group was significantly lower than that in the OLTCI group(P<0.05).Anesthesia maintenance period: the percentage of adequate anesthesia in CLTCI group was higher than that in OLTCI group(P<0.05).The percentages of overshoot and undershoot periods in CLTCI group were lower than those in OLTCI group(P<0.05).3.Comparison of the evaluation system indexes:GS score,Wobble and MDAPE in CLTCI group were lower than those in OLTCI group(P<0.05).TCI performance in both groups were within the acceptable range(MDPE <15%,MDAPE <30%)?4.Comparison of propofol plasma concentration:Comparison within the group: There was no significant difference between Cm and Cp of propofol in two groups(P>0.05),Cm> Cp.Comparison between groups: The difference of the Cm value in CLTCI group and OLTCI group at t1 ~ t5 time point was statistically significant(P<0.05).5.Comparison of propofol and remifentanil:There was no significant difference in mean velocity,target concentration and frequency of remifentanil between the two groups(P>0.05).The mean velocity,target concentration of propofol was no significant difference between the two groups(P>0.05).The frequency of propofol in CLTCI group was significantly higher than that in OLTCI group(P<0.05).6.Comparison of PaO2,PaCO2 and the use of vasoactive drugs :There was no significant difference in PaO2,PaCO2 and the use of atropine,ephedrine,esmolol,urapidil and nitroglycerin between the two groups(P>0.05).7.Comparison of opening eyes time,extubation time and the incidence of anesthesia complications:The opening eyes time,extubation time in CLTCI group was significantly shorter than that in the OLTCI group(P<0.05).There was no significant difference between the two groups in intraoperative awareness,physical response and postoperative shivering and nausea and vomiting.Conclusion:NT-guided closed-loop target-controlled infusion of propofol in the induction and maintenance of the depth of anesthesia is more stable than the open-loop target control infusion.It can reduce the fluctuation range of NTI and keep the cycle stable.The patients with postoperative anesthesia awake is more faster and extubation time is shorter.It indicates that the optimized closed-loop system is safe and feasible in gastrointestinal tumor surgery. |
PDF Full Text Request