Introduction:
Purulent complications worsen the prognosis in patients with acute necrotizing pancreatitis (ANP). Recently procalcitonin (PCT) was proposed as a diagnostic criterion of bacterial contamination of pancreatic necrotic tissue.

Aim of the research:
To evaluate the efficacy of PCT for the early diagnosis of infectious complications of ANP.

Material and methods:
We performed a prospective cohort study of 151 patients with ANP. Before interventional treatment, plasma samples were collected for PCT determination. According to microbiological assay, they were categorized into 4 groups: SIRS without infection, local infection, and sepsis and septic shock. The utility of PCT for diagnosis of infectious complications of ANP was determined by ROC-analysis.

Results:
Infected ANP was diagnosed in 89 (55.6%) patients. Local purulent complications were established at 27 cases, sepsis in 33, and septic shock in 29 patients. In 62 patients with sterile ANP the PCT concentration was higher than in healthy individuals and reached 1.34 ±0.19 ng/ml (p = 0.045). The development of infected ANP was accompanied by an increase of PCT concentration in patients with sepsis to 5.03 ±1.38 ng/ml (p = 0.001) and septic shock – up to 7.21 ±1.91 ng/ml (p = 0.001), while in persons with localized form it was 2.03 ±0.48 ng/ml (p = 0.072). Procalcitonin level above 4.0 ng/ml was prognostically unfavourable for the survival of patients.

Conclusions:
Serum PCT level is an effective tool for the diagnosis of generalized infectious complications of ANP. Its level over 4.0 ng/ml indicates an unfavourable prognosis for patients’ survival.