Correlation Analysis Of CVP NT-ProBNP With Bedside Ultrasound Evaluation Of Internal Jugular Vein Collapse Point In Patients With Heart Failure

Background and purposeHeart failure patients suffer from decompensation of normal cardiac function and then hospitalization and repeated treatment,which brings great economic pressure to families and patients.Systemic circulation and pulmonary circulation congestion caused by excessive volume load are the main reasons for the continuous deterioration of patients’condition.Controlling patients’fluid load in hospital is the key to the treatment of heart failure;however,it is correct in clinical work.Evaluating the volume of blood vessels is very difficult,and the current use of several capacity monitoring tools in clinical practice is very limited.Although the value of central venous pressure（CVP）in assessing the volume of blood vessels has been greatly questioned,it is still the most important tool clinicians use to evaluate volume status and cardiac preload.Central venous catheterization is a common parameter;however,central venous catheterization for monitoring central venous pressure（CVP）is an invasive procedure with the risk of infection and bleeding,and conventional central venous catheterization for monitoring CVP is almost impossible in general wards;therefore,the purpose of this study is to evaluate the changes of internal jugular vein collapse points in patients with different types of heart failure through a non-invasive method,i.e.,bedside ultrasound.CVP was estimated and its correlation with NT-Pro BNP was evaluated.Volume load and cardiac function were assessed to guide fluid therapy in patients with heart failure.Case Collection and Methods1 Case CollectionFrom January 2018 to March 2019,EICU,Affiliated Hospital of Taishan Medical College was selected.The patients ranged in age from 62 to 80 years old,with an average age of 70.24 years old.The age of all subjects was>18 years old.Among them,there were24 cases of coronary heart disease,15 cases of hypertension,14 cases of hypertension complicated with coronary heart disease,3 cases of rheumatic heart disease and 4 cases of expansionary heart disease.All the subjects could successfully perform central venous catheterization.Exclusion criteria:the right internal jugular vein showed badly,the patients with severe infections such as pericardial tamponade,renal insufficiency and sepsis were all informed and consented to the experiment.2 Experimental methodsAccording to the European Guidelines for Diagnosis and Treatment of Heart Failure2016,according to left ventricular ejection fraction（LVEF）,patients were divided into three groups:HFr EF group（EF<40%）,HFp EF group（EF<50%）and HFmr HF heart failure group（EF 40%～49%）.There were 20 patients in each group,and basic clinical data such as age,weight,blood pressure,creatinine and basic diseases were recorded.All patients were recorded and examined by bedside ultrasound.CVPni and left ventricular ejection fraction（LVEF）were measured at the vertical height of internal jugular vein collapse point and xiphoid process.Cardiac central venous catheterization was performed in all patients.CVP parameters were continuously monitored as the gold standard CVPi.NT-Pro BNP was also measured at the same time of CVPni.2.1 A method for invasive measurement of central venous pressureThe patient was placed in a supine position.The physician in the intensive care unit performed routine central venous puncture.The right subclavian vein was selected for puncture.After successful central venous puncture,the monitor was connected to record the central venous pressure of five consecutive cardiac cycles.The average value of the central venous pressure was taken and recorded.2.2 Non-invasive monitoring of central venous pressure by bedside ultrasoundThe right internal jugular vein was scanned with a linear probe in a 45 degree semi-recumbent position.The transverse and longitudinal images of the right internal jugular vein were obtained.The vertex of the collapsed segment of the right internal jugular vein was clearly identified and marked on the body surface.Because the wall of the venous tube is less elastic,smaller pressure may lead to its deformation.Keep the position unchanged,take the sternal angle of the patient as the projection point of the right atrium center on the body surface,and measure the vertical distance between the above two points with two rulers.The height represents CVPni,in units of cm H₂O.2.3 Immunochemiluminescence detection of NT-Pro BNPStar child product reagent,chemiluminescence immunoassay was used to detect the concentration of NT-Pro BNP.3 Statistical analysisSPSS 22.0 software was used for statistical analysis.Pearson correlation analysis and paired t test were used between CVPi and CVPni;P<0.01 was statistically significant,CVPi was the gold standard,CVPi（>12cm H2O）was used as high pressure state,ROC curve was drawn;Pearson correlation analysis of CVPni and NT-Pro BNP was carried out,P<0.01 was statistically significant.4 RESULTS AND CONCLUSION4.1 EF reserved type（HFp EF）heart failure groupPaired t-test was performed on 20 patients with EF normal heart failure using two methods.The CVPni value was 8.275±2.37.The CVPi value was 10.67±5.70,P=0.011.Pearson correlation coefficient:CVPni vs CVPi:r=0.868,P<0.001.With CVPi as the gold standard and CVPi>12mm Hg as the CVP increase,the ROC curve was constructed for the CVPni measured in 20 patients,and the area under the ROC curve was 0.929.When CVPni was 9.8cm,the sensitivity and specificity of the increased CVPi were 0.83 and 0.93,respectively.Pearson correlation coefficient between CVPni and NT-Pro BNP,CVPni vs NT-Pro BNP:r=0.555,P<0.01.4.2 EF intermediate（HFmr EF）heart failure groupPaired t-test was performed on 20 EF intermediate heart failure patients with CVPni:8.19±1.65.The CVPi value was 10.96±3.67,P<0.001.Pearson correlation coefficient:CVPni vs CVPi:r=0.899,P<0.001.With CVPi as the gold standard and CVPi>12mm Hg as the central static pressure,the ROC curve was constructed for the CVPni measured in 20patients,and the area under the ROC curve was 0.958.When CVPni:8.4cm was the diagnostic threshold,the increased sensitivity and specificity of the diagnostic CVP were1.00 and 0.92 respectively.Pearson correlation coefficient between CVPi and NT-Pro BNP,CVPni vs NT-Pro BNP:r=0.312,P=0.18.4.3 EF reduced（HFmr EF）heart failure groupPaired t-test was performed on 20 patients with ef-reduced heart failure using two methods:CVPni:8.67±3.84;CVPi:13.4±6.28,P=0.006;Pearson correlation coefficient:CVPni vs CVPi:r=0.731,P<0.001;Using CVPni gold standard and CVPi>12mm Hg as the central venous pressure,the ROC curve of CVPni obtained from 20 patients was established,and the area under the ROC curve was 0.952.When CVPni was 8.2cm,as the diagnostic threshold,the increased sensitivity and specificity of diagnostic CVP were 0.93and 1.00 respectively.Pearson correlation coefficient between CVPni and NT-Pro BNP,CVPni vs NT-Pro BNP:r=0.376,P=0.102.5 conclusionThere is a significant correlation between noninvasive CVP measured by bedside ultrasound at the collapse point of internal jugular vein and invasive central venous catheter monitoring CVP.This noninvasive assessment method can replace invasive central venous catheter pressure measurement in the future,which is convenient for clinicians to timely and conveniently assess the volume status of patients with heart failure and improve the prognosis of patients.In addition,there was a moderate correlation between CVPni and NT-Pro BNP in EF reserved heart failure group,but no correlation between EF reduced heart failure group and EF intermediate heart failure group.This conclusion needs further clinical study.In this study,the application of bedside ultrasound to evaluate the correlation between internal jugular vein collapse point and CVP,NT-Pro BNP provides a new direction for noninvasive assessment of heart pressure and heart function.