Effect Of Continuous Infusion Of Remimazolam Tosilate On Short-term Postoperative Delirium In Older Patients Undergoing Total Hip/knee Arthroplasty

Background and objectivePostoperative delirium(POD)is a common postoperative complication and is associated with many adverse outcomes.POD is the result of multiple factors,among which old age and bone and joint surgery are predisposing factors for POD.Previous studies have identified benzodiazepinoids as a predisposing factor that can increase the risk of delirium,but the effect of remimazolam tosilate(hereinafter referred to as remimazolam),a new ultra-short-acting benzodiazepine,on POD in older patients undergoing total hip/knee arthroplast has not been known.This study aims to compare the effect of remimazolam and sevoflurane on the incidence of POD in older patients undergoing unilateral total hip/knee arthroplasty,so as to provide reference for clinical application.MethodsA total of 256 older patients aged≥65 years with American Society of Anesthesiologists(ASA)grade I to III who were scheduled for elective total hip/knee arthroplasty under general anesthesia in Qilu Hospital of Shandong University from February 2022 to December 2022 were selected.Simple and complete randomization was carried out by random number table method.According to the ratio of 1:1,the patients were divided into 2 groups:sevoflurane group(group S)and remimazolam group(group R),and the grouping was hidden.128 patients were included in each group.Anesthesia induction:etomidate 0.2mg/kg,sufentanil 0.4ug/kg and rocuronium 0.6mg/kg were administered intravenously and ultrasonuse-guided nerve block was performed in both groups.Anesthesia maintenance:Patients in group R were continuously infused intravenously with remimazolam 0.3-1.5mg/kg/h and remifentanil 0.1-0.2ug/kg/min;Patients in group S were inhaled with sevoflurane with 0.7-1.5 minimum alveolar effective concentration(MAC)and continuously infused intravenously with remifentanil 0.1-0.2ug/kg/min.This was a prospective,double-blind,randomized controlled trial:neither the patients nor the anesthesiologists who collected and analyzed the data were aware of the group assignments.The primary outcome was the incidence of delirium in the first 3 days after surgery assessed by the Chinese version of 3-minute diagnostic confusion assessment method(3D-CAM)].Secondary outcome measures included intraoperative dosage of remifentanil,time to recovery after withdrawal,systolic blood pressure(SBP),diastolic blood pressure(DBP)and heart rate(HR)before anesthesia(T1),after induction(T2),30min after surgery(T3),at the end of surgery(T4),and immediately after laryngeal mask withdrawal(T5),white blood cell(WBC)and C-reactive protein(CRP)levels,the incidence of intraoperative adverse events and postoperative adverse reactions,the degree of pain assessed by visual analogue scale(VAS),and the cognitive function of the first 3 days after surgery assessed by Mini-mental State Examination(MMSE).Results1.There was no significant difference in general data between the two groups(P>0.05),which was comparable.2.The incidence of POD in group R was 9.38%,and that in group S was 14.06%.There was no significant difference in the incidence of POD in the first 3 days after operation between the two groups(P>0.05).There was no significant difference in MMSE score between the two groups the first day before operation and the first three days after operation(P>0.05).3.Compared with group S,SBP,DBP and HR in group R were higher at T3(P<0.05),and there was no significant difference in SBP,DBP and HR between the two groups at T1,T2,T4 and T5(P>0.05);The incidence of intraoperative hypotension and bradycardia in group R was lower(P<0.05),and the incidence of nausea and vomiting on the first day after operation was also lower(P<0.05).There was no significant difference in adverse reactions between the two groups on the second and third days after operation(P>0.05).4.Compared with group S,the recovery time in group R was shorter(P<0.05),and the levels of WBC and CRP in group R were lower one day after operation(P<0.05).There was no significant difference in the intraoperative dosage of remifentanil and rocuronium,infusion volume,blood loss,hemoglobin(Hb)at the end of operation,anesthesia time,and operation time between the two groups(P>0.05).5.There was no significant difference in VAS scores of rest and activity between the two groups the first day before operation and the first three days after operation(P>0.05).ConclusionFor patients aged 65 years and older undergoing total hip/knee arthroplasty surgery,compared with sevoflurane,continuous use of remimazolam tosilate as a general anesthetic did not increase the risk of POD in the first three days after surgery,and had less impact on intraoperative hemodynamics,shorter recovery time,lower incidence of postoperative nausea and vomiting,and improved surgical efficiency and anesthesia quality,and reduced complications,and facilitated postoperative rehabilitation of older patients.