[The influence of left ventricular-arterial coupling on the prognosis of elderly patients with septic shock].

OBJECTIVE: To investigate the influence of left ventricular-arterial coupling(VAC) on clinical prognosis of elderly patients with septic shock. METHODS: A total of 56 elderly septic shock patients were enrolled in this study, all of whom were admitted to Department of Intensive Care Unit in Zhejiang Hospital from August 2014 to October 2015.The patients were divided into two groups according to the status of left ventricular-arterial coupling when septic shock was diagnosed, which were left ventricular-arterial uncoupling group(UC group) and left ventricular-arterial coupling group(C group). Various parameters were recorded, including blood lactate level, central venous oxygen saturation(ScvO2), serum level of N-terminal pro-brain natriuretic peptide(NT-proBNP) and cardiac troponin Ⅰ(cTNⅠ), dose of vasoactive drugs, the total fluid volume and urine volume per hour within 24 hours. The 28-day survival rate was a key index of prognosis. Multivariate logistic regression was taken to analyze risk factors related to death within 28 day. RESULTS: Compared with C group, UC group had lower values of left ventricular ejection fraction[(42.43±4.76)% vs (53.17±3.01)%; P<0.01] and cardiac index[(2.36±0.68) L·min(-1)·m(-2) vs (2.93±0.45)L·min(-1)·m(-2); P<0.01]. Yet serum levels of NT-proBNP[lg NT-proBNP 3.93±0.53 vs 3.40±0.63; P=0.004] and cTNⅠ [lg cTNⅠ-0.16±0.68 vs-1.03±0.69; P<0.001] in UC group were higher than those in C group. Moreover, the total fluid volume within 24 hours [(3 806.3±831.4) ml vs (3 142.0±770.0) ml; P=0.016], blood lactate level[(5.61±2.68) mmol/L vs (3.93±1.59) mmol/L; P=0.043] and dose of norepinephrine[(0.630±0.300)μg·kg(-1)·min(-1) vs (0.292±0.234)μg·kg(-1)·min(-1;) P=0.001] in UC group were greater than those in C group, while ScvO2[(60.75±2.91)% vs (64.42±2.19)%; P<0.001] and urine volume per hour[(0.518±0.358)ml vs (0.926±0.678)ml; P=0.007] were less than those in C group. Compared with C group, UC group had a lower 28-day survival rate[43.2%(19/44) vs 9/12; P=0.049]. Ea/Ees ratio was negatively correlated with LVEF, ScvO2(r=-0.686, P<0.001; r=-0.411, P=0.002), positively correlated with NT-proBNP, cTNⅠ(r=0.294, P=0.028; r=0.363, P=0.006), yet no obvious correlation was noticed with blood lactate level(r=0.170, P=0.21). Multiple logistic regression analysis showed that VAC(OR=11.187, 95%CI 2.489-50.285; P=0.002), lactate level (OR=1.727, 95%CI 1.164-2.563; P=0.007) and lg cTNⅠ(OR=0.247, 95%CI 0.079-0.779; P=0.017) were independent risk factors affecting 28-day mortality. Conclutions: In elderly patients with septic shock, left ventricular-arterial uncoupling indicates a lower 28-day survival rate, worse cardiac function and tissue perfusion. Ea/Ees ratio might sever as a predictive indicator of 28-day mortality.