The Influence Of Different Blood Flow Settings On The Measurement Accuracy Of Central Venous Pressure During Continuous Blood Purification Therapy

Objective: Volume management is basic and important in continuous blood purification(CBP).Central venous pressure(CVP)is an important indicator of volume management in CBP.Whether different blood velocity settings affect the measurement accuracy of CVP during CBP treatment has not been determined yet.If CBP was suspended in order to accurately measure CVP,there might be a risk of pipeline coagulation.In this study,we studied the effect of different blood flow on the accuracy of CVP measurements during the process of CBP.The aim of our study is to testify if we could measure CVP accurately and without suspending CBP.Methods: Patients admitted to the Department of Critical Care Medicine,Dalian Municipal Central Hospital from August 1,2017 to November 30,2018 for CBP treatment were selected as the study subjects.According to the blood purification catheter and CVP monitoring catheter position,in accordance with the random number table,patients were divided into three groups: group A was the same three-lumen catheter with both blood purification catheter and CVP monitoring catheter located in superior vena cava;group B1 was two different catheters with blood purification catheter and CVP monitoring catheter located in superior vena cava;group B2 was the blood purification catheter located in femoral vein,and CVP monitoring catheter located in superior vena cava.According to the purpose of the study,case tables were designed to collect basic information of patients and clinical data.CVP measurements at different blood flow velocities(0 m L/min,50 m L/min,100 m L/min,150 m L/min,200 m L/min,250 m L/min,300 m L/min)were monitored and recorded in the Statistical Table of Clinical Information of Patients.SPSS23.0 software was used for data analysis.Results:1.A total of 61 patients met the inclusion criteria.There were 21 cases in group A,20 cases in group B1,and 20 cases in group B2.2.No matter all patients or groups A,B1 or B2,different blood flow Settings(0m L/min,50 m L/min,100 m L/min,150 m L/min,200 m L/min,250 m L/min,300 m L/min)had no effect on the CVP measurement values.3.No matter the direct or reverse connection,different blood flow Settings(0m L/min,50 m L/min,100 m L/min,150 m L/min,200 m L/min,250 m L/min,300 m L/min)had no effect on the CVP measurement values.4.There was a strong negative correlation between blood flow and arterial pressure(p<0.01),that is,the higher the blood flow was(0~300m L/min),the lower the arterial pressure was.There was a strong positive correlation between blood flow and veins(p<0.01),that is,the higher the blood flow(0~300m L/min),the higher the venous pressure.5.Regression analysis showed that there was no correlation between arterial pressure,venous pressure and CVPConclusions:1.There is no influence on the accuracy of central venous pressure measurement by different blood flow settings during continuous blood purification therapy.This conclusion is also valid in the direct connection,the reverse connection and the different position of the catheter.It can provide some reference for accurate measurement of CVP without pausing CBP in clinical practice.2.The blood flow of continuous blood purification was negatively correlated with arterial pressure and positively correlated with venous pressure.3.There is no correlation between arterial pressure,venous pressure and CVP in continuous blood purification...