Procalcitonin as a Marker for Early Diagnosis of Sepsis

Sepsis is a critical condition often caused by bacterial infection and associated with death and mortality. The prognosis of this disease depends on early diagnosis and proper treatment. Definite diagnosis of sepsis is positive blood culture and this test needs a long time to perform, so other biochemical parameters such as procalcitonin serum level has been introduced. To determine sensitivity, specificity, positive and negative predictive value of procalcitonin serum level at first time and 72 h after admission and to compare it with blood culture test for diagnosis of sepsis. Blood sample for blood culture, prepheral blood smear at first time and procalcitonin serum level measuring by semi quantitative method at first and 72 h after admission were sampled. Nine patients had positive blood cultures. Peripheral blood smear was positive in 38 patients, (29 patients: gram stain positive, 6 patients: gram stain negative and 3 patients: both gram positive and gram negative). At first time 76.8% had positive procalcitonin (>0.5 ng mL) and after 72 h 65% of patients had positive procalcitonin. Sensitivity, specificity, positive and negative predictive value of procalcitonin at the first time were 100, 16,16 and 100% and for procalcitonin after 72 h respectively were 75, 35, 15 and 90%. This study showed that sensitivity of procalcitonin serum level can be used for diagnosis of sepsis. Procalcitonin increased as severity of sepsis and this study suggests high serum level of procalcitonin after 72 h might indicate poor outcome.