Abstract:

Objective To explore the diagnostic values of stroke volume variation (SVV) and central venous pressure (CVP)   in low circulatory
blood volume by comparing  the correlations between SVV,CVP and low circulatory blood volume.Methods 120 patients undergoing partial hepatectomy were randomly selected.After general anesthesia with endotracheal intubation and the begining of the operation, nitroglycerin was administered to the patients via vein  with three separate stages of the dosage regimen of 1,2,and 3 μg?kg-1?min-1.The hemodynamic variables including  stroke volume variation (SVV),central venous pressure (CVP),mean arterial pressure (MAP),heart rate (HR),stroke volume index (SVI),cardiac index (CI) and systemic vascular resistance index (SVRI) of the patients  were detected at 4 time points:before infusion (T0),15 min after infusion of nitroglycerin 1 μg?kg-1?min-1 (T1),15 min after infusion of  2 μg?kg-1?min-1 nitroglycerin(T2),15 min after infusion of  3 μg?kg-1?min-1 nitroglycerin  (T3).The maximum of sensitivity and  specificity and   the receiver operating characteristic curve (AUC) of SVV and CVP  responding to CI were detected byoperating characteristic (ROC) curve; Pearson rank correlation method was used to analyze  the correlation between SVV, CVP and CI.Results The AUC of SVV and CVP responding to CI were AUCCVP 0.713 (95%CI, 0.623-0.804) and AUCSVV 0.930 (95%CI, 0.883-0.977).When the SVV was 12.5%,the sum of sensitivity and specificity was the biggest with  ensitivity of 81% and  specificity of 95%;when the  CVP was 5.5 mmHg,the sum of sensitivity and specificty was the biggest with   sensitivity of 73% and  specificity of 59
%. The value of AUCSVV was larger than that of AUCCVP (P<0.05).The values of Pearson’s correlation coefficient of SVV,CVP and CI were rSVV-CI=－0.671
（95%CI －0.455－－0.67）and rCVP-CI= 0.551（95%CI 0.744－0.591） and there were no significant difference between rSVV-CI  and rCVP-CI (P>0.05).
Conclusion SVV and CVP are good parameters for diagnosis of low circulatory blood volume variation.The predictability of SVV for low circulatory blood volume is higher than CVP,and SVV is more sensitive and specific.

Key words: stroke volume variation, central venous pressure, low circulatory blood volume, nitroglycerin