Procalcitonin and MR-proAdrenomedullin combination in the etiological diagnosis and prognosis of sepsis and septic shock

Procalcitonin and Mid-regional pro Adrenomedullin have been proposed for sepsis diagnosis, antibiotic therapy guidance and prognosis. A retrospective analysis of PCT and MR-proADM on 571 consecutive patients with sepsis diagnosis was performed. Median values were compared using the non-parametric Mann-Whitney's test. Receiver operating characteristic analysis was performed to define cutoff points for sepsis diagnosis. Pretest odds, posttest odds, and posttest probability have been calculated. Data were analyzed using Med-Calc 11.6.1.0 software. PCT resulted excellent in gram-negative, but less performant in gram-positive and fungal etiologies. MR-proADM values resulted homogenously distributed within the different microbial classes and increased significantly in septic shock. PCT highest PPV value was found to distinguish gram-negative from fungal sepsis and septic shock (>3. 57 ng/mL, PPV 0.96 and > 8.77 ng/mL, PPV 0.96, respectively). Good diagnostic accuracy was evidenced to discriminate gram-negative from gram-positive septic shock (>3.88 ng/mL PPV 0.89). Lower diagnostic accuracy was evidenced to discriminate gram-negative and gram-positive sepsis (>0.80 ng/mL, PPV 0.78) and gram-positive from fungal septic shock (>1.74 ng/mL PPV 0.75). The lowest PCT PPV (0.28) was found in gram-positive and fungal sepsis distinction. MR-proADM discriminating cut-offs were homogeneously distributed in Gram-negative and Gram-positive sepsis and were higher in septic shock, but not influenced by pathogen etiologies. MR-proADM cut-off values > 3.39 nmol/L in sepsis and >4.33 nmol/L in septic shock were associated with significant higher risk of 90-days mortality. In conclusion, PCT and MR-proADM combination represents an advantage for sepsis diagnosis and for 90-days mortality risk stratification.