Effects Of Left Ventricular-arterial Coupling On Hemodynamics And Organ Function And Prognosis In Critically Ill Patients

Objective: The study was designed to explore the effects of left ventricular-arterial coupling on hemodynamics and organ function and prognosis by using bedside ultrasound.The influencing factors of left ventricular-arterial coupling were also discussed.Methods: We performed a Clinical observational study from July 2016 to December 2016 involving patients receiving mechanical ventilation admitted to the medical Intensive care unit(ICU)at the Fourth Hospital of Hebei Medical University in China.Patients were identified with the following inclusion criteria: age>18 years;admitted to ICU;received mechanical ventilation.The exclusion criteria included the patients whose age less than18 years;the ICU lenth of stay less than 24 hours;patients who had acute coronary syndrome,acute myocardial infarction,acute decompensated heart failure,acute arrhythmia,myocarditis or pericarditis;known history of dilated cardiomyopathy;and a variety of causes of left ventricular outflow tract obstruction;people who had acute pulmonary embolism and right ventricular outflow tract obstruction,pulmonary valve/tricuspid stenosis,severe pulmonary artery deformity;pregnant and lactating women;patients who abandon active treatment during hospitalization;and could not get a clear ultrasound image.The clinicians determined the ventilator parameters;All patients underwent ultrasonography within 24 hours of enrollment.Ultrasound indicators were as follows: left ventricular ejection fraction(EF),cardiac output(CO),the mitral/ tricuspid annulus plane systolic excursion(MAPSE/TAPSE),the left and right ventricle diastolic early stage E,the left and right ventricle diastolic late stage A,the mitral/ tricuspid annulus ventricular free wall diastolic early /late tissue Doppler peak e ’/ a’,the left/right ventricular E/A,E/e,pulmonary artery systolic pressure(PASP),renal resistance index(RRI).Blood pressure,heart rate,systolic blood pressure,diastolic blood pressure,mean arterial pressure,respiratory rate,central venous pressure and other vital signs were recorded when performing ultrasound examinations.The liquid balance,ventilator parameters and laboratory parameters were also recorded.Evaluating the Acute Physiology and Chronic Health Evaluation II(APACHE II),Sequential Organ Failure Assessment(SOFA)score within 24 hours after admission.Prognostic indicators: mechanical ventilation days,the ICU lenth of stay and 28 days mortality.According to this formula effective arterial elastance(Ea)/ ventricular end elastance(Ees)=(1/EF)-1,the patients were divided into coupled group(Ea/Ees 0.5-1)and uncoupled group(Ea/Ees> 1 or <0.5).To explore the effects of left ventricular-arterial coupling on hemodynamics and organ function and prognosis by using bedside ultrasound.And the influencing factors of left ventricular-arterial coupling were also discussed.Statistical analysis was performed with SPSS software.Results:1 A total of 128 patients were included in the study,63 patients were in the coupled group and 65 patients were in the uncoupled group.The incidence of left ventricular-arterial coupling mismatch in critically ill patients was about50.8%.Significant difference between the two groups was in the APACHE II score,the uncoupled group was higher than that of the coupled group(19(11)VS17(6.25),P=0.017),whereas there was no significant statistical differences in hemodynamics parameters,liquid balance,Ventilator Parameters.2 Hemodynamic parametersThere was no Significant statistical differences in the ventricular size,flow index,right ventricular preload between the two groups(P>0.05).For the right ventricular afterload: PASP,the coupled group was lower than that of the uncoupled group(17.36 mm Hg(15.88 mm Hg)VS 29.22 mm Hg(22.78 mm Hg),P=0.004),there was a significant statistical differences between the two groups.And there were no Significant statistical differences in tissue perfusion parameters between the two groups.3 Comparison of organ function3.1 Comparison of the left ventricular systolic and diastolic functionFor the EF,the coupled group was higher than that of the uncoupled group(56%(7%)VS45%(8%),P<0.01),there was a significant statistical differences between the two groups.significant differences between the two groups was in the left ventricular E/A(0.79(0.38)VS0.91(0.55),P=0.026),while other parameters had no Significant statistical differences.3.2 Comparison of the right ventricular systolic and diastolic functionAll the parameters had no significant statistical differences between the two groups.3.3 Renal,liver function and Myocardial markersSignificant differences between the two groups were in Cardiac troponin I and Brain natriuretic peptide(BNP)(0.01μg/L(0.025μg/L)VS0.04μg/L(0.255μg/L),P<0.01;98.74 pg/ml(122.46 pg/ml)VS133.86 pg/ml(296.8 pg/ml),P=0.05),whereas there was no Significant statistical differences in renal,liver function between the two groups.4 Prognostic indicatorsThere were significant statistical differences between the two groups in mechanical ventilation days(3days(1.5 days)VS4 days(3.5 days),P=0.01).The28-day mortality rates were 12.6%(8/63)and 16.9%(11/65)in the two groups,respectively.But there was no significant difference between them(x2=0.452,P=0.502).5 The possible influencing factors of left ventricular-arterial couplingTo explore the possible influencing factors,we assessed with multivariate regression models using gener,age,APACHE II scores,MAPSE,the left ventricle E,A,e’,TAPSE,the right ventricle E,A,right ventricular afterload PASP.We found they were not the factors of left ventricular-arterial coupling.Conclusions:1 The incidence of left ventricular-arterial coupling mismatch in critically ill patients was higher,about50.8%.2 There was no significant difference in the 28-day mortality between the two groups.Left ventricular-arterial coupling mismatch prolonged mechanical ventilation time.3 Our study failed to find the influencing factors of the left ventriculararterial coulpling.