Evaluation of Procalcitonin Accuracy for the Distinction Between Gram-Negative and Gram-Positive Bacterial Sepsis in Burn Patients

Abstract

Sepsis is the main cause of death in burns. Early institution of antimicrobial therapy is crucial to optimize outcomes but superfluous therapy increases adverse events, microbial resistance, and costs. Blood cultures are the gold standard for diagnosis but can take 48 to 72 hours. Biomarkers are used to help sepsis diagnosis and distinction between Gram-negative and Gram-positive bacterial cause. The aim of this work is to evaluate procalcitonin (PCT) accuracy for this distinction in burn patients. Retrospective observational study of adult septic burn patients with ≥15% total burn surface area admitted from January 2011 to December 2014 at a Burn Unit in Portugal. A statistical analysis was done, evaluating the correlation between PCT levels on the day of the first positive blood culture and microbiological data for Gram-negative and Grand-positive bacteria. Patients with mixed bacterial and/or fungal blood cultures were excluded. Data were summarized by quartiles statistics. Blood cultures were positive in 189 patients: 75 (39.7%) showed growth for Gram-negative and 114 (60.3%) for Gram-positive bacteria. Patients with Gram-negative bacteria have significantly higher PCT levels. Receiver operating characteristic curve analysis showed accuracy for Gram-negative discrimination with area under the curve = 0.687. Most elevated levels were related to nonfermentative Gram-negative bacteria and by Klebsiella pneumoniae and other Enterobacteriaceae. PCT levels were significantly higher in burn patients with Gram-negative sepsis comparing to patients with Gram-positive sepsis and controls. The determination of PCT levels may help the choice of empirical antimicrobial therapy while microbiological culture results are not available, despite not fully ensuring the desirable degree of precision. An early and adequate antimicrobial therapy is the main step for the management of septic patients. 1 Unfortunately, differential diagnosis between sepsis and the systemic inflammatory response triggered by trauma is difficult, particularly in burn patients where the usual clinical signs of sepsis are frequently present even in the absence of microbial infection. 2 For instance, burn injuries leading to upregulation of the hypothalamic thermal center, physiologic release of catecholamines and cytokines, shift of fluids and the consequent cardiovascular changes, can produce hyperthermia, tachycardia, hypotension, etc., that are transitory and do not reflect any microbial invasion but just a tentative of adjustment of human body systems to the changes in the homeostatic equilibrium.

Serum IL-6 and procalcitonin are two promising novel biomarkers for evaluating the severity of COVID-19 patients

“…Hence, use of a PCT assay may be helpful in controlling bacterial infection secondary to the pneumonia caused by SARS-CoV-2. In addition, several studies have shown that PCT can be used to distinguish Gram-negative from Gram-positive bacteria and fungal bloodstream infections [18–20] . This would allow the choice of antimicrobial agents empirically when microbiological results are not available, despite the lack of desirable precision.…”

“…In addition, several studies have shown that PCT can be used to distinguish Gram-negative from Gram-positive bacteria and fungal bloodstream infections. [18][19][20] This would allow the choice of antimicrobial agents empirically when microbiological results are not available, despite the lack of desirable precision. It may be taken as an additive diagnostic value of PCT when used for the evaluation of patients with COVID-19.…”

Red cell distribution width as a predictor of late‐onset Gram‐negative sepsis

“…In this study, it was observed that RDW significantly increased in preterm infants with LOGNS and that an RDW value of >19.50% was a significant marker in predicting LOGNS. It is of utmost importance to initiate timely antimicrobial therapy during a sepsis episode and prevent an unnecessary exposure of broad‐spectrum antibiotics to the patient . We speculate that the increased inflammatory response owing to Gram‐negative sepsis results in dysregulation of erythropoiesis, which in turn leads to increase in the RDW levels; these increased levels might help the clinician in selecting an empiric antibiotic therapy.…”

Comparing outcomes between culture-positive and culture-negative septic shock in a PICU: A retrospective cohort study

“…In our study, PCT in the CPSS group was significantly higher than that in the CNSS group. Several studies have indicated that PCT levels are significantly higher in adult patients with gram-negative sepsis than in adult patients with gram-positive sepsis ( 25 – 28 ). However, in this study, subgroup analysis showed that there was no significant difference in PCT levels between gram-positive and gram-negative septic shock in children.…”