Serum procalcitonin in diagnosis of bacteremia.

Objective: To (a) determine the diagnostic value of procalcitonin (PCT) in differentiating sepsis with or without bacteremia, (b) evaluate the correlation of PCT levels to severity of sepsis, (c) establish the prognostic value in predicting the outcome of sepsis and (d) evaluate the correlation among different assays.

Material And Method: A prospective study was carried out from August through November 2007. Blood for PCT levels and culture were drawn simultaneously.

Results: Fifty-six patients with clinical suspicious of sepsis were enrolled in the study; bacteremia (n = 30) and non-bacteremia (n = 26). There were good correlations between the PCT levels measured by three assays (p < 0.001). At the threshold of 0.5 ng/mL, PCT had > 90% sensitivity for diagnosis of bacteremia. Of the bacteremic group, median PCT levels measured by Kryptor and VIDAS assays were 12.4 and 16.6 ng/mL respectively. In the non-bacteremic group, median PCT levels measured by Kryptor and VIDAS were 4.2 and 4.9 ng/mL respectively. PCT levels were significantly higher in the bacteremic group (p = 0.04). The optimum thresholds to discriminate between these two groups were found to be 5, 6.5 and 2 ng/mL for Kryptor, VIDAS and PCT-Q, respectively. In addition, correlations of PCT and increasing values of the APACHE II score were observed. PCT levels in the severe sepsis and MOD group were also found to be significantly higher

Conclusion: PCT was highly sensitive in detecting bacteremia, although not very accurate in differentiating bacteremic from non-bacteremic SIRS in adult patients.