Biomarkers of sepsis in burn patients

Introduction

Sepsis is still the major cause of death in the late post-traumatic period in patients with major burns. Diagnosis of sepsis remains difficult in these patients where signs of sepsis may be present in the absence of real infection. This study attempted to assess whether the plasma procalcitonin (PCT) level was related to sepsis in burned patients.

Methods

PCT was measured over the entire course of stay in patients with predictive signs of sepsis according to Burn French Society Criteria (SFETB) for the presence of infection. The patients were assigned to two groups depending on the clinical course and outcome: A = no septic patients, B = septic patients. Optimum sensitivity, predictive values, and area under the receiver operating characteristic (ROC) curve were evaluated.

Results

Over a 6-month period starting from 1 July 2008 to 31 December 2008, 157 patients were admitted. Sixty-two were investigated, 40 in group A and 22 in group B. Procalcitonin was significantly higher in the septic group (7.26 ± 7 ng/ml) compared with the no septic group (0.25 ± 0.32 ng/ml). Area under the curve was 0.94 on the day of sepsis diagnosis. A PCT cut-off value of 0.75 ng/ml was associated with the optimal combination of sensitivity (85%), specificity (87%), positive predictive value (91%), and negative predictive value (73%). In surviving septic patients the PCT value was significantly lower than in deceased septic patients (3.5 ± 0.87 ng/ml vs 10.18 ± 9.6 ng/ml). The PCT cut-off value for optimum prediction of outcome in septic patients was 3.66 ng/ml with sensitivity (91%), specificity (75%), positive predictive value (78%), and negative predictive value (90%).

Conclusions

Procalcitonin appears to be a powerful marker of sepsis in burn patients. It is sensitive, specific, reliable and easy to measure. A high PCT concentration (>3.66 ng/ml) would indicate poor outcome in septic patients.