Predictive Study On Arteriovenous Fistula Function By The Ratio Of Prepump Arterial Pressure To Blood Pump Speed

BackgroundBy the end of 2019,the number of maintenance hemodialysis(MHD)patients was more than 630,000,and increased year by year.Vascular access is the lifeline of MHD patients.Arteriovenous fistula(AVF)is the preferred type of VA for hemodialysis due to fewer complications and longer lifespan compared with other types of vascular access.Even so,the life of the AVF is limited for various factors with 50.5%of 5-year patency.Close monitoring of AVF functions and timely intervention can prolong the service life of AVF.Prepump arterial pressure(Pa)is a type of pressure monitoring in extracorporeal circuits during hemodialysis treatment,which can be used not only to enhance the safety of treatment but also to reflect the function of vascular access.However,most hemodialysis nurses had low compliance with Pa monitoring.And,it is hard for Pa monitoring to play its role due to the unidentified safety range.The absolute value of the ratio of Pa to blood pump speed(|Pa/Qb|)reflects the resistance of blood pump to draw blood,and it was used to judge or predict the dysfunction of catheter dysfunction.However,there were few studies had focused on the indicating and predictive role of |Pa/Qb| in AVF dysfunction.ObjectiveThe study was conducted to prove the impact of |Pa/Qb| on AVF dysfunction,explore the safe scope of |Pa/Qb| for clinical reference,evaluate the influence of|Pa/Qb| on hemodialysis adequacy and explore the influencing factors of |Pa/Qb|.MethodsOne year’s data of MHD patients in 3 hospitals were collected retrospectively.We evaluated the pattern of the association between |Pa/Qb| and AVF dysfunction during one year using a Cox proportional hazards regression model with restricted cubic splines.Then,according to its results,patients were grouped to compare AVF function and hemodialysis adequacy in different intervals of |Pa/Qb|.Multiple linear regression was used to analysis the influencing factors of |Pa/Qb|.ResultsA total of 490 patients were analyzed,with an age of 55(44,66)years.There were a total of 85 cases of AVF dysfunction.|Pa/Qb|*10(HR:1.74,95%:1.32-2.29),Charlsen Complications Index(HR:1.15,95%CI=1.00-1.31,P=0.046)and hemodialysis≥3 times per week(HR:3.71,95%CI=1.16-11.80,P=0.027)were the risk factors for AVF function by analysis of Cox proportional risk model.There was a U-shaped association between |Pa/Qb| and the risk of AVF dysfunction(pnon-linearity<0.001).|Pa/Qb|<0.30 and>0.52 were potentially risk intervals for AVF dysfunction.The AUC under the ROC curve for the prediction of AVF dysfunction by the above division of |Pa/Qb| was 0.661(95%CI:0.593-0.728),P<0.001.The sensitivity and specificity values were 54.1%and 78.2%,respectively.The positive and negative predictive values were 34.1%and 89.0%.The result of mixed linear model shows that the impact of |Pa/Qb| on hemodialysis adequacy was not significant.Hemodialysis adequacy was positively correlated with women,hemodialysis time,Qb,and negatively correlated with body mass index and mean arterial pressure during hemodialysis(P<0.05).The multiple linear regression analysis of |Pa/Qb| shows a negative correlation between |Pa/Qb| and mean arterial pressure,age,and a positive correlation between|Pa/Qb| and β2 microglobulin,hemoglobin(P<0.05).Conclusions1.|Pa/Qb| between 0.30～0.52 was the safe scope of AVF function maintaining.When |Pa/Qb|<0.30 or>0.52,the risk of AVF dysfunction increased significantly.When |Pa/Qb|>0.52,there may be AVF dysfunction at the inflow of AVF.When|Pa/Qb|<0.30,the dysfunction at the outflow of AVF may occur.Nurses should evaluate AVF function in time.2.The correlation of |Pa/Qb| and hemodialysis adequacy was not significant.It is suggested that when formulating a hemodialysis prescription,medical staffs should not ignore the impact of |Pa/Qb| on AVF in order to pursue adequacy of hemodialysis.3.|Pa/Qb| was influenced by mean arterial pressure,age,β2 microglobulin andhemoglobin concentration.Attention should be paid to related factors in clinical work to reduce the adverse effects of |Pa/Qb| on AVF.4.|Pa/Qb| monitoring can not only help nurses to evaluate the function of AVF,but also judge the rationality of Qb setting,identify adverse events and correct them in time to prolong the service life of the AVF.