Abstract: Objective To investigate the correlation between procalcitonin (PCT) levels and the infection site/pathogenic microorganisms. Method 120 patients aged 20 to 85 years who were admitted to the surgery intensive care unit (SICU) from August 2012 to August 2014, who had a procalcitonin drawn were evaluated. PCT blood specimens were collected at morning in SICU; blood cultures data, sputum culture data, urine culture data were studied to determine the causative organism. Result 120 patient records were reviewed. Patients without a known infection/source of sepsis had a mean procalcitonin of 3.79. Those with pneumonia had a procalcitonin of 24.87 (p=0.038). Those with a UTI had a mean procalcitonin of 52.19（P=0.0009）. Patients with a bloodstream infection had a mean procalcitonin of 27.73(p=0.0052). Those with Gram-positive sepsis had a procalcitonin of 25.87 (p=0.0161) and those with Gram-negative sepsis at 45.13 (p= 0.0203). Those with fungal in-fections had a procalcitonin of 45.13 (p=0.0017). Conclusion PCT levels were significantly different in different types of infections and pathogenic microorganisms so that procalcitoninmay play a role in guiding treatment for Pyemiaby indicating causative organism and infection type.

Key words: procalcitonin, Pyemia, infection, marker