Value of procalcitonin combined with Infection Probability Score in predicting infection in patients with liver failure

Objective To investigate the value of procalcitonin ( PCT) combined with Infection Probability Score ( IPS) in predicting the possibility of infection in patients with liver failure. Methods A retrospective analysis was performed for the clinical data of patients with liver failure who were admitted to The First Hospital Affiliated to Soochow University from January 2015 to June 2018. According to the clinical diagnosis, the patients were divided into infection group and non-infection group, and the two groups were compared in terms of clinical features, common laboratory markers, IPS score, and sequential organ failure assessment ( SOFA) score. The t-test and the Wilcoxon rank-sum test were used for comparison of continuous data between two groups, and the chi-square test was used for comparison of categorical data between two groups. A multivariate logistic regression analysis was performed to analyze the influencing factors for infection and establish a diagnostic model of PCT combined with IPS score. The receiver operating characteristic ( ROC) curve was used to assess the predictive efficiency of PCT combined with IPS score in infection. Results A total of 179 patients with liver failure were enrolled, among whom 123 ( 68. 72%) experienced infection. Among the 123 patients with infection, 99 ( 80. 49%) had pulmonary infection, 49 ( 39. 84%) had abdominal infection, and 40 ( 32. 52%) had infections at 2 or more sites. The multivariate logistic regression analysis showed that PCT ( odds ratio [OR]= 3. 822, 95% confidence interval [CI]: 1. 714-8. 523, P = 0. 001) and IPS score ( OR = 1. 125, 95% CI: 1. 030-1. 230, P = 0. 009) were independent predictive factors for liver failure with infection. The ROC curve analysis showed that PCT combined with IPS score had the strongest predictive efficiency in liver failure with infection with an area under the ROC curve ( AUC) of 0. 857 ( 95% CI:79. 7-90. 5) , with a significantly higher predictive efficiency than IPS alone and PCT alone ( 0. 857 vs 0. 803/0. 802, both P < 0. 05) , and PCT combined with IPS score had a positive likelihood ratio as high as 3. 40 and a negative likelihood ratio as low as 0. 28. Conclusion Both PCT and IPS score can predict infection in patients with liver failure with similar predictive efficiency, while a combination of PCT and IPS score has a better predictive value.