The association between plasma N-terminal pro-B-type natriuretic peptide and extravascular lung water index in patients with septic shock / 中国中西医结合急救杂志

ABSTRACT

Objective To study the dynamic change in plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels and its correlation with extravascular lung water index (EVLWI) in patients with septic shock. Methods Sixty-two patients with septic shock admitted to Department of Critical Care Medicine of Beijing Shijitan Hospital were enrolled. The patients were divided into survival group(39 cases)and non-survivors group (23 cases)according to 28-day prognosis. Venous blood was collected after intensive care unit(ICU)admission. The changes in plasma NT-proBNP and hemodynamics indexes levels were analyzed to evaluate their predictive value for clinical outcomes. Results Acute physiology and chronic health evaluation Ⅱ(APACHEⅡ)score(23.2±2.5 vs. 28.1±2.6),sequential organ failure assessment(SOFA score7.74±2.80 vs. 12.43±3.00)and hemodynamics indexes including EVLWI〔ml/kg7.0(6.0,8.0)vs. 9.0(7.0,12.0)〕,blood lactate(mmol/L)3.60±2.30 vs. 10.40±2.70)and NT-proBNP〔ng/L945.0(228.0,1 246.0)vs. 5 471.0(3 308.0,11 174.0)〕in survivors were significantly lower than those in non-survivors,and cardiac index〔CI(L?min-1?m-2)4.23±0.85 vs. 3.31±0.74〕, global ejection fraction(GEF0.205±0.054 vs. 0.149±0.054)were significantly higher than those in non-survivors (P<0.05 or P<0.01). Correlation analysis showed a positive correlation was found between NT-proBNP and EVLWI (r=0.277,P=0.010),and negative correlations were found between NT-proBNP and CI(r=-0.367,P=0.001), GEF(r=-0.259,P=0.017). No correlation was found between NT-proBNP and GEDVI,SVRI. Receiver operating characteristic curve(ROC curve)analysis showed that the area under the ROC curve(AUC)for plasma NT-proBNP predicting the outcome of septic shock patients was 0.869±0.042,95% confidence interval(95%CI)was 0.786-0.952,with the maximum sum of sensitivity and specificity 1.695 to determine NT-proBNP predicting septic shock patient's death cut-off value was 2 071 ng/L,under this cut-off value,the sensitivity was 81.4% and specificity,88.1%. The maximum AUC for EVLWI predicting the outcome of patients with septic shock was 0.690,cut-off value was 7.5 mL/kg,under this cut-off value,the sensitivity was 69.8% and specificity,66.7%. Maximum AUC for CI predicting the outcome of patients with septic shock was 0.785,cut-off value was 3.48 L?min-1?m-2,under this cut-off value,the sensitivity was 69.8%and specificity,66.7%. Maximum AUC for GEF predicting the outcome of septic shock patients was 0.794,cut-off value 0.175,under this cut-off value,the sensitivity was 76.2% and specificity, 81.4%. Multivariate analyses showed CI and NT-proBNP levels were independent predictors of the prognosis〔CIP=0.001,odds ratio(OR)=9.183,95%CI 2.362-35.694;NT-proBNPP=0.024,OR=1.000,95%CI 0.999-1.000〕. Conclusion The plasma NT-proBNP level which is correlated significantly to EVLWI can evaluate the severity of septic shock and can predict the prognosis of such patients.