Procalcitonin kinetics as a prognostic marker in severe sepsis/septic shock

Abstract

Background and aims: To evaluate the prognostic value of change (fall) in serum procalcitonin level (PCT) in critically ill adults with severe sepsis/septic shock. Methods: This was a prospective observational study in a general purpose Intensive Care Unit of a teaching Institute. PCT was measured at admission (D0) and after 72-96 h (D4) by electrochemi-luminescence immunoassay (BRAHMS PCT kit) in adults (<18 years) admitted with severe sepsis or septic shock. Change in procalcitonin values from D0 to D4 was correlated with the primary outcome, that is, 28 days mortality. All results are reported as median (interquartile range). Results: A total of 171 (100 males) of 181 patients were included. The median age was 46 years (range 19-79). 137 patients were in septic shock and 34 in severe sepsis. The sequential organ failure assessment (SOFA) score in all patients was 11 (9-14).91 (53.2%) patients survived at 28 days (survivors). The baseline procalcitonin was similar in two groups (3.48 [1.04-15.85] vs. 5.27 [1.81-23.57] ng/ml in survivors and nonsurvivors [NS] respectively). The procalcitonin change was 1.58 (0.20-8.52) in survivors and 0.28 (-1.38-6.17) in NS (P = 0.01). The C-statistic of percentage change in procalcitonin from D0 to D4 to predict survival was 0.73 (95% confidence interval [CI]: 0.65-0.82) when compared to 0.78 (95% CI: 0.71-0.86) for change of SOFA score. For an absolute fall in procalcitonin of <1 ng/ml, a 70% fall predicted survival with 75% sensitivity and 64% specificity. Conclusions: In critically ill-patients with severe sepsis/septic shock, change (fall) in procalcitonin is associated with good outcome.