Effect Of Swing Arm Exercise With Dumbbell Load On Arteriovenous Fistula In Hemodialysis Patients:A Randomized Controlled Trial

BackgroundHemodialysis is the main method of renal replacement therapy for patients with end-stage renal failure.Autologous arteriovenous fistula(AVF)is the preferred vascular access for maintenance hemodialysis patients.It is estimated that the proportion of AVF in the permanent vascular access of hemodialysis patients in China is 85-90%.However,the life of the AVF is limited,and is associated with dialysis vintage,underlying disease,exercise and other factors.And the reported primary patency rates of AVF in maintenance hemodialysis patients are 60%at 1 year and 51%at 2 years.More importantly,functional exercise is the key to AVF function maintenance.The handgrip exercise is the regular exercise.However,these exercises present some deficiencies,such as inability to grasp grip strength and poor compliance.Although the patients are required to follow the handgrip exercise postoperatively,the patient's exercise effect is often difficult to guarantee.Furthermore,the 2006 KDOQI guidelines pointed out that carrying heavy objects draped over the fistula arm is avoided.As a result,patients overprotect their fistula arm,which is prone to induce disuse muscular atrophy and reduce the quality of life of patients in the long term.Therefore,starting from the point of "no lifting heavy objects with the fistula limb",dumbbell was selected as the exercise tool,and the effect of swing arm exercise with dumbbell load on AVF function maintenance was explored through a randomized controlled trial.By evaluating the safety and effectiveness of 6-pound load exercises,it provides evidence for further improving the point of view in KDOQI guidelines that "avoid carrying heavy items draped over the access arm".ObjectivesIn this study,6-pound dumbbells were used as exercise tools to explore the effect of swing arm exercise with dumbbell load on arteriovenous fistula in patients undergoing maintenance hemodialysis,and further evaluate the routine of "no lifting heavy objects with the fistula limb".MethodsThis study was a randomized controlled trial.This study was carried out between June 2018 and December 2018 in the blood purification center of a third-level first-class hospital.Patients with maintenance hemodialysis who used an AVF as a permanent vascular access were enrolled.Participants were randomized into the dumbbell group and handgrip group.Both groups underwent the exercises for 20 minutes a day for up to 3 months on non-dialysis days.The dumbbell group held 6-pound dumbbells,while the handgrip group squeezed rubber balls.Baseline data,including demographic data,clinical data,information on the vascular access,AVF hemodynamic index measured by Doppler ultrasound,and dialysis records were collected at the enrollment.AVF hemodynamic index measured by Doppler ultrasound and dialysis records were collected at 1,2 and 3 months after intervention.The primary outcome was blood flow of AVF draining vein(DV).The secondary outcomes were blood flow of AVF proximal arterial(PA),blood flow of AVF brachial artery(BA),DV diameter,and incidence of adverse events.Results1.The significant interaction effect was noted in DV blood flow(F=7.514,P<0.001).There was a statistically significant difference in DV blood flow between the two groups(F=5.335,P=0.024)and the main effect of time was statistically significant(F=21.679,P<0.001).The effect of time on blood flow in the dumbbell group was statistically significant(F=20.474,P<0.001).The DV blood flow in the dumbbell group increased by 121.10(-109.29,251.36),136.00(-193.93,324.15),172.93(-90.49,282.65)ml/min at the 1st month,2nd month,3rd month,respectively.The effect of time factor on DV blood flow in the was not statistically significant in the handgrip group(F=2.78,P=0.060).At 2nd and 3rd month after intervention,there was a statistical difference in DV blood flow between the dumbbell group and the handgrip group(P<0.05).After the intervention,the interaction effect and group effect of PA blood flow,BA blood flow and DV diameter were not statistically significant(P>0.05),but the difference between different time points was statistically significant(P<0.05).PA blood flow,BA blood flow and DV diameter of the both groups showed an increasing trend with the extension of exercise time.2.During the 3-month follow-up period,there was 1 case of thrombosis detected in the dumbbell group.There were 2 participants with high-flow fistulas in the dumbbell group,and there were 3 in the handgrip group.There was no significant difference in the high-flow fistula rate between the two groups(5.3%vs 7.5%).The participants had no clinical symptoms of high-output cardiac failure.In both groups,there were no other adverse events reported.Conclusions1.Arm exercises in hemodialysis patients can improve the blood flow of the AVF and the diameter of the DV.Swing arm exercise with dumbbell load is an economical,safe,effective intervention to maintain AVF function.2.Hemodialysis patients can safely use their fistula arm to lift 6-pound objects,suggesting that patients with AVF dysfunction can use 6-pound dumbbells for fistula exercise.3.It is recommended that the relevant clinical practice guidelines supplement the view that the fistula cannot lift heavy objects,so as to prevent the fistula arm from being used.However,as the study duration was only three months,the safety range of lifting heavy objects with the fistula arm remains to be further explored.