The Effect Of Using Combined Methods To Prevent Hypotension In Induction Period Of Radical Gastrectomy Patients Under Combined General-epidural Anesthesia

Background and objectiveCombined general-epidural anesthesia used in the chest and abdominal surgery,has a lot of advantages,such as,it can relieve the stress reaction,convenient the management of intraoperative circulation,reduce intraoperative bleeding, reduce the dosage of general anesthetics, avoid delayed recovery,improve the postoperative analgesia and reduce analgesia complication, improve the safety of anesthesia.But,it often experience hypotension in the induction period of combined general-epidural anesthesia.Induction period hypotension can cause delayed recovery, increase the risk of perioperative cerebral infarction, extend the time of postoperative care unit and hospital stay, and even increase postoperative mortality.How to predict and prevent the happening of the induction period hypotension has always been a concern to the anesthesiologist.There are already a lot of literatures report through infusion liquid crystal and colloid before induction, combined general anesthetics with ephedrine, deoxidation adrenaline and methoxamine during induction of general anesthesia to prevent the happening of the induction period hypotension,they have a certain effect, but also have many shortcomings.In order to look forward simple and effective method to prevent of hypotension in general-epidural anesthesia induction period, this research compares the effect on the induction period of hypotension through different methods, raising legs in the induction period, intravenous pump metaraminol in advance,and raising legs as while as pump metaraminol in advance,all of the methods combined with supplement of the blood volume.Materials and MethodsApproved by the hospital ethics committee,from May 2014 to December 2014,a total of 88 ASA grade I-II patients,who were scheduled for elective radical gastrectomy surgery under combined general-epidural anesthesia were enrolled.They were randomly divided into four groups:the control group(group A),the leg-raising group(group B),the metaraminol group (group C),the leg-raising and metaraminol group(group D),22 cases in each group.Regular forbidden diet preoperative,did not give medication before anesthesia.After the patients entering into the operating room, peripheral intravenous cannula were placed,continue to input liquid crystal.All of the patients intravenous fluids were given simultaneously, preload could be maintained。 After 5 minutes of rest,monitor ECG (electrocardiogram),BP(blood pressure) and SpO2(pulse oxygen saturation).They were measured two times before anesthesia and took the average date between them as the base date. Took the right side, selected T8-9 clearance, epidural punctured and catheter upward. According to the height and weight of the patients, give the epidural test quantity 3-5 ml of 1.5% lidocaine,5 min later test the anesthesia plane. If the anesthesia effect is not ideal, left out of this research. Use midazolam 0.04 mg/kg, etomidate 0.2 mg/kg, fentanyl 0.03 mg/kg, rocuronium 0.7 mg/kg for general anesthesia induction.According to gender and weight,place 3 or 4 LMA laryngeal mask,use 1.5% sevoflurane inhalation to maintain anesthesia.According to need to add muscle relaxant.According to the epidural test plane results give an additional 1.5% lidocaine 4-6 ml when isinfect the skin. Start the operation 15 min after the induction. Group B adjusted bed to make patients with lower limb raised 30°after epidural punctured,group C gave metaraminol 0.3 mg at the same time of the induction of general anesthesia,and then continuous pumped metaraminol 2 mg/h,group D adjusted bed to make patients with lower limb raised 30 °after epidural punctured,and then continuous pumped metaraminol 2 mg/h.If the blood pressure is 20% lower than the base value, give metaraminol 0.2-0.3mg; If the heart rate is lower than 45 times/min, inject atropine 0.5 mg.If blood pressure is 20% higher than the base value stop use metaraminol.Recorded the BP、HR of the basic dates,3 min after epidural drug delivery,before the induction of general anesthesia,and 3 min,6 min,9 min,12 min,15 min,20 min,25 min,30 min after induction. Recorded when low blood pressure, high blood pressure, bradycardia occurred,and deal with it timely.Use SPSS 19.0 software to analysis the data statistically, record measurement data with mean±standard deviation (x±S), measurement data comparison with repeated measures analysis of variance, P< 0.05 for the difference was statistically significant, count data were analysis by chi-square test.Results1.Patients participate in the experiment did not happen serious arrhythmia,did not use atropine. The measurement data is normal distribution, and homogeneity of variance.2.Hypotension occurred during induction period:the incidence of low blood pressure during induction period of group A was significantly higher than that of other groups, the difference was statistically significant (P<0.05)3.Hypertension occurred during induction period:there are two cases occurred high blood pressure after induction in group A,B and C,but there are four cases occurred high blood pressure after induction in group D,and all cases blood pressure down to normal gradually after stopped metaraminol, did not use antihypertensive drugs.4. Heart rate:the heart rate of all patients decreased after induction, and each group have the same change trend, there was no statistically significant difference (P> 0.05).5.Blood pressure:the difference between groups was statistically significant (P<0.05).After the induction,the BP of all the groups are lower than the basic dates, but the blood pressure reduction of proup A was significantly greater than the other groups, group D has a more smoothly hemodynamic.ConclusionUsing combined method (Adding the liquid,raising leggs and pumping metaraminol advanced)to prevent hypotension in induction period of radical gastrectomy patients under combined general-epidural anesthesia was a simple and reliable method.