Procalcitonin as prognostic marker in severe sepsis of abdominal origin

Introduction

We evaluated the utility of procalcitonin (PCT) as a marker of outcome in severe sepsis of abdominal origin (SSAO). SSAO is one of the most prevalent pathologies in surgical ICUs (sICUs). Mortality from 19 to 70% has been reported. Biomarkers are basic tools for diagnosis, follow-up and outcome of sepsis. One of the most studied in last decades has been PCT. Its levels and kinetics could be useful to evaluate the outcome of septic patients.

Methods

We studied all patients admitted to a sICU with SSAO, from 2007 to 2008. Data collected were: PCT levels on days 1, 3 and 7, gender, age, APACHE II on admission, positivity of surgical cultures, microorganisms isolated and sepsis origin (community or nosocomial).

Results

Sixty-nine patients were included. Mortality was 23%. Median age was 64.94 years. Median APACHE II was 16.43 points. At day 1, PCT levels were higher in survivors (S) than in exitus (E) (S: 29.22 ng/ ml vs. E: 14.93 ng/ml, P < 0.05). PCT levels were influenced by gender (males: 27.74 ng/ml vs. females: 15.04 ng/ml, P < 0.05), positive cultures (positive: 25.25 ng/ml vs. negative: 13.49 ng/ml, P < 0.05) and isolation of Gram-negative microorganisms (Gram-negative: 27.53 ng/ml vs. Gram-positive: 14.77 ng/ml, P < 0.05). Patients with community-acquired sepsis had higher levels of PCT on admission (37.53 ng/ml vs. 13.29 ng/ml, P < 0.02). None of these factors had an influence on mortality. On day 3 PCT levels where higher in S (S: 20.65 ng/ml vs. E: 16.23 ng/ml, P < 0.05). On day 7 PCT levels were higher in E (S: 3.54 ng/ ml vs. E: 12.88 ng/ml, P < 0.05). PCT kinetics was different depending on outcome. E patients presented persistently higher levels, whereas PCT in S decreased over time (P < 0.05). PCT on day 7 best identified outcome (AUC ROC 0.768). PCT ≥3.5 ng/ml predicted mortality (sensitivity 55%, specificity 73%).

Conclusion

PCT on day 7 and PCT kinetics can be useful to predict outcome in SSAO. PCT is higher in community-acquired sepsis, when surgical cultures are positive, in Gram-negative isolations and in males.