The role of propionic acid at diagnosis predicts mortality in patients with septic shock.

PURPOSE: This study aims to assess the diagnostic and prognostic value of propionic acid in patients with septic shock on a medical intensive care unit (ICU).

METHODS: Serum propionic acid and clinical common cytokines levels were measured within 24h after the diagnosis of sepsis, and the Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Sequential Organ Failure Assessment (SOFA) score, and Mortality were recorded in ICU. A 28-day and 90-day follow-up was performed for all patients.

RESULTS: A total of 118 septic patients were enrolled in this study. The propionic acid was higher in patients with septic shock compared with sepsis. Multivariate logistic regression analysis showed that propionic acid was independent predictor of sepsis (odds ratio: 1.279; 95% confidence interval: 1.069-1.530; P=0.007) and septic shock (odds ratio: 1.859; 95% confidence interval: 1.342-2.576; P<0.001) and ICU mortality (odds ratio: 1.331; 95% confidence interval: 1.107-1.600; P=0.002), 28-day mortality (odds ratio: 1.259; 95% confidence interval: 1.046-1.514; P=0.015) and 90-day mortality (odds ratio: 1.304; 95% confidence interval: 1.092-1.558; P=0.003). The receiver operating characteristic curve (AUC) analysis showed the areas under of propionic acid on ICU admission day for predicting sepsis and septic shock were 0.773 and 0.85 respectively, the areas under of propionic acid for predicting ICU mortality, 28-d and 90-d mortality were 0.779, 0.739 and 0.809 respectively. Using a PA cutoff of 0.053 and 0.095 for predicting sepsis and septic shock respectively, the sensitivity was 97.62% and 85.5%, and the specificity was 58% and 83.5%, respectively. Using a PA cutoff of 0.139 for predicting ICU mortality, 28- and 90-day mortality, the sensitivity was 69.39%, 67.44% and 69.09% respectively, and the specificity was 78.26%, 73.33% and 82.54% respectively.

CONCLUSIONS: Propionic acid showed diagnostic capacity to diagnose septic shock and revealed prognostic information for mortality.