Effect Of Dexmedetomidine On Intestinal Barrier Function In Patients Undergoing Gynecologic Laparotomy

Objective:The intestinal barrier is playing an important role in resisting external pathogens and toxins.The damage of Intestinal barrier function can lead to intestinal toxin and bacterial translocation,endotoxemia and sepsis and increased perioperative complications and mortality.As an a2-adrenergic receptor agonist,dexmedetomidine has the characteristics of regulating stress,anti-inflammatory and anti-apoptosis,and has been widely used in clinical anesthesia and plays a role in multi-organ protection.This study was to evaluate the effect of dexmedetomidine on intestinal barrier function in patients undergoing gynecologic laparotomy.Methods:Forty patients scheduled for Open Myomectomy(OM)and Open Hysterectomy(OH)were randomly divided into two groups(n=20).Patients in group D received dexmedetomidine administeration at a loading dose of 1 ug/kg for 15 minutes before induction,followed by an infusion rate of 0.3 ug·kg-1·h-1 to 30min before the end of surgery.The patients in group C received normal saline instead of dexmedetomidine.All patients were underwent total intravenous anesthesia.Anesthesia induction:fentanyl 3ug/kg iv?propofol 1-3mg/kg iv,vecuronium 0.1mg/kg iv.After tracheal intubation,IPPV mode was used for both group.Ventilation parameter setting:tidal volume 8-10ml/kg?ventilation frequency 10-14 bpm,suction ratio:1:2,oxygen flow rate:2L/min.Intraoperative maintenance of airway peak pressure<20mmHg,end-tidal carbon dioxide 30-40mmHg.Intraoperative maintenance:continuous pumping of propofol 4-8mg·kg-1·h-1,remifentanil 0.2ug·kg-1·min-1,intermittent injection of vecuronium to maintain satisfactory muscle relaxation.The same perioperative fluid regimen was used in both groups:supplemented compensatory expansion capacity,amount of physiological demand,intraoperative blood losses,cumulative losses and the third space losses;the compensatory expansion capacity was 5 ml/kg?and the infusion was completed before induction;cumulative losses=amount of physiological demand X fasting time;amount of physiological demand:the first 10kg infusion dose is 4ml/kg,the second 10kg infusion dose plus 2ml/kg?20kg or more per kg infusion dose plus lml/kg.Half of the amount is replenished in the first hour,and the remaining liquid was infused at followed 2 hours.The third space losses is infused by 4ml·kg-1·h-1.Intraoperative infusion was comprised with electrolyte and hydroxyethyl starch.The crystal-colloid ratio was 2:1.The intraoperative blood pressure was maintained at±20%of preoperative,HR:60-80 bpm.Postoperative analgesia was performed 1 hour before the end of the operation with dezocine 0.1 mg/kg+parecoxib 40 mg iv.The same intravenous analgesia was used in both groups after surgery.The heart rate(HR)and mean arterial pressure(MAP)were observed before dexmedetomidine infusion(T0),10 minutes after intubation(T1),10 minutes after the start of surgery(T2),l hour after laparotomy(T3),2 hour after laparotomy(T4).The intraoperative hypotension(MAP<60 mmHg)and bradycardia(HR<50bpm)of each group were recorded.The serum concentrations of diamine oxidase(DAO)and endotoxin were detected at TO,T4 and T6(24 hours after surgery).Results:1.There was no significant difference in preoperative conditions between the two groups(P>0.05).2.The infusion and fluid loss of operation were no significant difference between the two groups(P>0.05).The incidence of bradycardia and hypotension in group D was significantly higher than that in group C(P<0.05).3.Compared with T0,the concentration of serum endotoxin and diamine oxidase in group D and group C were both increased at T4,the difference was statistically significant(P<0.05).At T4,the concentration of serum endotoxin and diamine oxidase in group C were higher than group D,the difference was statistically significant(P<0.05).At T6,the concentration of serum DAO in group D was significantly lower than that in group C,and the difference was statistically significant(P<0.05).4.Compared with group C,in group D,the number of patients who needed additional analgesic drugs after operation was significantly reduced,and the difference was statistically significant(P<0.05).5.Compared with group C,the time of gastrointestinal motility recovery in group D was significantly shorter,and the difference was statistically significant(P<0.05).Conclusion(s):We have found that gynecologic laparotomy can cause intestinal barrier function damage and an increase in serum concentration of DAO and endotoxin,while dexmedetomidine can reduce this damage.The application of dexmedetomidine may cause hypotension and bradycardia,but the side effects were easy to correct and there were no perioperative complications.After all dexmedetomidine can be safely used clinically and has a protective effect on intestinal barrier function.