Study Of Dexmedetomidine On The Prevention Of HeightenedIntraocular Pressure And Other Complications In Patients With Laparoscopic Gynecological Surgery

Objective: To investigate the effectiveness of dexmedetomidine(DEX) on the prevention of elevated intraocular pressure and other complications in patients undergoing gynecologic laparoscopic surgery.Methods: Seventy five patients(ASAⅠ-Ⅱ) undergoing laparoscopic hysterectomy were randomly divided into three groups, with25cases in each group. Experimental groups included group D1and group D2: Dexmedetomidine was intravenously administrated at a dose of0.5μg/kg at15min intervals before anesthesia induction, followed by a continuous infusion of0.2μg/kg/h in group D1and a continuous infusion of0.4μg/kg/h in group D2; In Control group(group C), the same volum of0.9%normal saline was given as control.All patients were performed intravenous anesthesia with propofol-remifentanil given by TCI. The IOP,MAP,HR,CVP,PETCO2and BIS were measured at5min(T0) after anesthesia induction, at10min(T1) and30min(T2) and60min (T3)after pneumoperitoneum(PP) and changed posture during surgery,and at10min(T4) after revocation of PP. Perioperative adverse reactions such as hypertension, hypotension, bradycardia, tachycardia, postoperative agitation, nausea,vomiting, and shivering were recorded,. VAS were recorded at2h after operation.Results:1. There were no significant differences in patients’ characteristics in the three groups.2. IOP: In each group, the IOP values gradually increased and reached a maximum at T3, and gradually decreased at T4.The IOP in the observational groups were significantly decreased than those of group C at T1.T2and T3(P<0.05). Comparison between group D1and D2, the IOP at each time point were no significant difference (P>0.05).3.Hemodynamic parameters:MAP: After pneumoperitoneum(PP) and changed posture，the MAP of three groups of patients were higher than the MAP of the same group at T0. The MAP of Group C were higher than those of the observational groups at each time point (P <0.05), The MAP in group D1were also higher than that in group D2from T0to T3(P<0.05).HR: Compared with the control group, HR of the observational groups were lower at the same time points (P <0.05); while compared with the group D1,HR in the group D2were lower (P <0.05).CVP: Compared with T0,values of CVP increased after PP in each group(P<0.05). As compared with the control group at T1﹑T2and T3,CVP was significantly decreased in the observational groups. And there was no significant difference between group D1and group D2at the same time point(P>0.05).4. PETCO2: The PETCO2of the three groups at T1﹑T2and T3were significantly increased compared to those at T0in each group (P <0.05), and then falled down to baseline levels after revocation of pneumoperitoneum. At the same time point, there was no statisctical significance among the three groups.(P>0.05).5. BIS:Compared to group C,BIS scores were lower at most time point in the observational groups（P<0.05）. Compared with group D1, BIS scores were lower in group D2at the same time point, but the difference was not statistically significant.(P>0.05).6.Correlation analysis: Changes of CVP and PETCO2of the three groups were positively correlated with the changes of IOP. But MAP had poor correlation with IOP. 7. Adverse reactions statistics: Compared to the other two groups, the incidence of perioperative complications was lower in group D1.Conclusions: The application of appropriate doses of DEX can prevent excessive elevated intraocular pressure in patients undergoing gynecological laparoscopic surgery, decrease the risk of visual acuity damage, and reduce various complications during perioperative period.