Correlation between shock index and severity of septic shock and its prognostic value / 中华危重病急救医学

ABSTRACT

Objective To discuss the correlation between shock index (SI) and severity and the values to forecast the prognosis in patients with septic shock. Methods 127 patients with septic shock admitted to intensive care unit (ICU) of Zhejiang Provincial People's Hospital from January 1st, 2016 to October 31st, 2017 were enrolled, and they were divided into survival group and death group according to the outcomes after 28-day hospitalized. The vital signs, laboratory indexes, acute physiology and chronic health evaluation Ⅱ(APACHEⅡ), sequential organ failure assessment (SOFA), lactate clearance rate (LCR) of 3 hours after fluid resuscitation, and shock index on admission (SI1) and shock index of 3 hours after fluid resuscitation (SI2) were compared between the two groups. The correlation among SI and APACHE Ⅱ, SOFA, LCR was analyzed. The receiver operating characteristic curve (ROC) was drawn to evaluate the prognostic value of SI in patients with septic shock. Results A total of 127 patients were included, 52 in survival group (40.9%) and 75 in death group (59.1%). The SI1, SI2, APACHE Ⅱ and SOFA in the death group were significantly higher than those in the survival group (SI1 1.62±0.46 vs. 1.35±0.32, SI2 1.36±0.24 vs. 0.93±0.15, APACHEⅡ17.5±4.0 vs. 13.6±3.5,SOFA 9.5±2.3 vs. 6.3±1.5), and LCR was significantly lower than that in the survival group [(14.4±5.2)% vs. (28.6±8.6)%], with statistically significant differences (all P < 0.01). The correlation analysis showed that SI1was significantly positively correlated with APACHEⅡ (r = 0.458, P = 0.000) and SOFA (r = 0.535, P = 0.000), SI2was also significantly positively correlated with APACHEⅡ (r = 0.624, P = 0.000) and SOFA (r = 0.656, P = 0.000), while SI1and SI2were significantly negatively correlated with LCR (r values were -0.348, -0.435, both P = 0.000), and the SI2were more remarkable. ROC curve analysis showed that the area under ROC curve (AUC) of SI1for predicting the prognosis of septic shock was 0.720 [95% confidence interval (95%CI) = 0.620-0.831, P < 0.05]; when SI1= 1.68, the sensitivity, specificity, Yoden index, positive predictive value and negative predictive value were 79.5%, 65.6%, 0.451, 0.759 and 0.636, respectively. The AUC of the SI2to predict prognosis of septic shock was 0.826 (95%CI =0.739-0.826, P < 0.05); when SI2= 1.37, the sensitivity, specificity, Yoden index, positive predictive value and negative predictive value were 85.7%, 87.6%, 0.733, 0.893 and 0.902, respectively. Conclusion Compared with SI1, SI2was more correlated with the severity in patients with septic shock and it had more values to predict prognosis.