['Serum procalcitonin (PCT) is considered to be a sensitive marker for the early recognition of severe infection. The aim of this study was to review the diagnostic accuracy of serum procalcitonin levels to predict the risk of septic shock and mortality in patients with secondary peritonitis.', 'We carried out a retrospective review of patients (November 2010 to November 2012) admitted to the surgical intensive care unit (ICU) with secondary peritonitis classified into localised peritonitis (LP) or diffuse peritonitis (DP) groups. Organ dysfunction was assessed with the SOFA score. Demographic data was collected as well as results for neutrophil count, C- reactive protein, blood lactate, and PCT levels. The primary end-point was ICU mortality.', 'From a total of 222 patients, 123 were allocated to the LP group and 99 to the DP group. Severe sepsis was observed in 41.9% of all patients in the DP group. The PCT levels increased significantly in the DP group, with the development of septic shock in 29 patients. Higher PCT levels were associated with an increased risk for septic shock with a cut-off value of 15.3 ng mL⁻¹ and an increased risk for mortality with a cut-off value 19.6 ng mL⁻¹. A total of 59.1% of those who developed septic shock died.'] Is serum procalcitonin a sensitive marker for septic shock and mortality in secondary peritonitis?