High Central Venous Pressure and Right Ventricle Size are Related to Increased Stroke Volume to Negative Fluid Balance in Critically Ill Patients

BackgroundThis study aimed to determine whether a negative fluid balance can increase stroke volume (SV) and the relationship between changes in hemodynamics variables.MethodsThis prospective study included patients with high central venous pressure (CVP) (≥8 mmHg) treated in the Critical Medicine Department of Peking Union Medical College Hospital. Patients were classified into two groups based on their right to left ventricle diastolic dimension (RVD/LVD) ratio using a cutoff value of 0.6. The hemodynamic and echo parameters of the two groups were recorded at baseline and after negative fluid balance. ResultsThis study included 71 patients: 35 in Group 1 (RVD/LVD≥ 0.6) and 36 in Group 2 (RVD/LVD <0.6). Of all patients, 56.3% showed increased SV after negative fluid balance. Cox logistic regression analysis suggested that a high CVP and RVD/LVD ratio were significant independent risk factors for SV increase after negative fluid balance in critically patients without underlying cardiac disease. The AUC of CVP was 0.894. A CVP> 10.5 mmHg provided a sensitivity of 87.5% and a specificity of 77.4%. The AUC of CVP combined with the RVD/LVD ratio was 0.926 ,which provided a sensitivity of 92.6% and a specificity of 80.4%. ConclusionHigh CVP and RVD/LVD ratio were identified as independent risk factors for RV volume overload in critically patients without underlying cardiac disease. A reduced intravascular volume may increase SV for these patients.