Effect Of Epidural Administration Of Low-dose Dexmedetomidine On Gastrointestinal Function In Patients With Gastric Cancer

AIM:To investigate the effects of epidural administration of low-dose dexmedetomidine on gastrointestinal function in postoperative patients with gastric cancer.METHODS:This trial adopted a randomized,double-blind,and controlled study manner,and included 81 patients aged 40-65 years,BMI 18-30kg/m2,ASAⅠ-Ⅲ,who underwent laparoscopic gastrectomy for the first time.They were randomly divided into three groups:Control group（Group C）:patients received TEA with ropivacaine alone and were intravenously infused with saline;Intravenous group（Group V）:patients received TEA with ropivacaine alone and were intravenously infused with dexmedetomidine;Epidural group（Group E）:patients received TEA with ropivacaine and dexmedetomidine,and were intravenously infused with saline.All patients underwent thoracic epidural puncture and catheterization before general anesthesia.Patients in group C were given 0.375%ropivacaine 6ml epidural.During the operation,0.375%ropivacaine 6ml/h was injected epidural and saline was continuously pumped intravenously.Patients in group V received 0.375%ropivacaine6 ml epidural and 0.5ug/kg dexmetomidine intravenously.During the operation,0.375%ropivacaine 6ml/h was injected continuously epidural,and 0.1μg kg^-1h^-1was injected intravenously.Patients in group E received 6ml epidural administration of0.375%ropivacaine combined with dexmetomidine 0.5ug/kg.During the operation,0.375%ropivacaine combined with dexmetomidine 0.1μg kg^-1h^-1was injected with6ml/h epidural pump and normal saline was injected intravenously.At the end of operation,0.2%ropivacaine were dosed in the epidural space for continuous analgesia（7ml/h were maintenance dosed,PCA dose of 3ml,locking time of 20min）.The primary outcome was the first postoperative exhaust time,and the secondary outcome included the amount of propofol during the operation;mean arterial pressure（MAP）and heart rate（HR）of patients at different time during the operation;the time of the first defecation and the time of intake of solid food after the operation;the degree of abdominal distension and the number of defecation three days after operation;visual analogue scale（VAS）three days after surgery;length of postoperative hospital stay;serum tumor necrosis factor-α（TNF-α）and diamine oxidase（DAO）levels before and three days after operation;and a proportional hazard regression model（COX）was established to analyze the risk factors for prolonging the first exhaust time after operation.RESULTS:Compared with group C and group V,the time of the first postoperative exhaust,defecation and solid food intake in group E was significantly shortened（P<0.01）.The degree of abdominal distension 3 days after operation was different between three groups（P<0.01）.However there was no difference in the frequency of defecation three days after surgery（P>0.05）.Postoperative gastrointestinal function recovery of patients in group E was 8 hours earlier,and the length of hospitalization was 1 day shorter compared with C group.The dosage of propofol used for maintenance anesthesia in group E was lower than group C and group V（P<0.05）.The VAS score of group E was significantly lower than that of group C within 12h after surgery（P<0.05）,and the remedial analgesic dose was also significantly decreased（P<0.01）.Compared with group C,the intraoperative HR of group E decreased significantly（P<0.05）,and MAP was significantly different only in 1min after anesthesia induction（P<0.01）.There were no evident differences in the content of TNF-αand DAO among the three groups（P>0.05）.The COX model assessed the ability of low-dose epidural dexmedetomidine to improve postoperative gastrointestinal function.According to the analysis model,sufentanil and preoperative albumin,also the the length of operation time was found to be the risk factors affecting postoperative gastrointestinal recovery.CONCLUSION:Epidural low-dose of dexmedetomidine can improve postoperative gastrointestinal function in patients with gastric cancer,enhance intraoperative sedation,and play a better analgesic effect within 12 hours.