Effect Of Dexmedetomidine On Postoperative Recovery In Elderly Patients Undergoing Knee Arthroplasty With Combined Spinal-Epidural Anesthesia Using Ropivacaine

Objective: To investigate the effect of dexmedetomidine on postoperative recovery in elderly patients undergoing knee arthroplasty with combined spinal-epidural anesthesia using ropivacaine.Methods: 80 elderly patients undergoing total knee arthroplasty in our hospital from June 2018 to June 2019 were randomly divided into control group and study group,and40 in each group.Patients in study group received combined spinal-epidural anesthesia using ropivacaine and intravenous dexmedetomidine,while patients in control group received combined spinal-epidural anesthesia using ropivacaine and equal dose of normal saline.Serum levels of superoxide dismutase(SOD),malondialdehyde(MDA),myeloperoxidase(MPO)were measured before tourniquet ligation(T1),5 minutes after tourniquet release(T2)and 30 minutes after tourniquet release(T3).Serum levels of C-reactive protein(CRP),interleukin-6(IL-6),tumor necrosis factors-α(TNF-α)were determined at T1,T2 and T3.Record hemodynamic indexes,revised facial pain score(FPS-R),sedation score,perimeter of suffered limb,functional recovery,knee joint score(KSS)and adverse reactions in perioperative period.Result:1.There were no significant differences in age,sex,BMI and ASA grade between two groups(P>0.05).2.There were no significant differences in hemodynamic parameters between the two groups at T1(P > 0.05).Systolic and diastolic pressure as well as heart rate in study group were lower than those in control group at T2 and T3(P < 0.05).3.There were no significant differences in MDA,MPO and SOD between the two groups at T1(P > 0.05).At T2 and T3 time points,serum levels of MDA and MPO in study group were lower than those in control group,and serum level of SOD in study group was higher than that in control group(P < 0.05).4.There were no significant differences of CRP,IL-6 and TNF – α between the two groups at T1(P > 0.05).Serum levels of CRP,IL-6 and TNF-α in study group were lower than those in the control group(P < 0.05)at T2 and T3.5.There were no significant differences of Ramsay Sedation score and FPS-R score between two groups at T1;FPS-R score in study group was lower than that in control group at T2 and T3(P < 0.05),and Ramsay Sedation score in study group was higher than that in control group at T2 and T3(P < 0.05).6.The perimeter of suffered limb in study group was smaller than that in control group,and the increase rate of perimeter in study group was lower than that in control group(P < 0.05).7.The time of active straight leg raising and active knee flexion to 90 ° in the study group was shorter than those in the control group(P < 0.05).8.There was no significant difference in KSS score between the two groups before operation(P > 0.05).The KSS score in study group was higher than that in control group(P < 0.05).9.There were no significant differences in the incidence of adverse reactions between two groups(P > 0.05).Conclusion: Dexmedetomidine can significantly reduce the oxidative stress response and inflammation in elderly patients undergoing knee arthroplasty with combined spinal-epidural anesthesia using ropivacaine.It relieves pain and enhances sedation,and has little disruption in hemodynamics,and improves postoperative recovery.