Diagnosing sepsis – The role of laboratory medicine

Abstract

Sepsis is the host response to microbial pathogens resulting in significant morbidity and mortality. An accurate and timely diagnosis of sepsis allows prompt and appropriate treatment. This review discusses laboratory testing for sepsis because differentiating systemic inflammation from infection is challenging. Procalcitonin (PCT) is currently an FDA approved test to aid in the diagnosis of sepsis but with questionable efficacy. However, studies support the use of PCT for antibiotic de-escalation. Serial lactate measurements have been recommended for monitoring treatment efficacy as part of sepsis bundles. The 2016 sepsis consensus definitions include lactate concentrations greater than 2 mmol/L (>18 mg/dL) as part of the definition of septic shock. Also included in the 2016 definitions are measuring bilirubin and creatinine to determine progression of organ failure indicating worse prognosis. Hematologic parameters, including a simple white blood cell count and differential, are frequently part of the initial sepsis diagnostic protocols. Several new biomarkers have been proposed to diagnose sepsis or to predict mortality, but they currently lack sufficient sensitivity and specificity to be considered as stand-alone testing. If sepsis is suspected, new technologies and microbiologic assays allow rapid and specific identification of pathogens. In 2016 there is no single laboratory test that accurately diagnoses sepsis.

Elevated Levels of Interleukin-27 in Early Life Compromise Protective Immunity in a Mouse Model of Gram-Negative Neonatal Sepsis

“…7B). IL-6 levels are increased in patients with infectious complications and are used clinically to provide a quantitative assessment of sepsis severity (42)(43)(44). Additionally, IL-6 levels correlate with the mortality rate in septic patients (45).…”

Role of leucocytes cell population data in the early detection of sepsis

“…Given the limitations of the above-mentioned biochemical markers, a wide variety of new markers related to microbiological products or the host’s inflammatory immune response have been proposed over the last few years 17. However, none of these markers can be recommended as a unique criterion for the diagnosis of sepsis, and experts recommend to use a combination of parameters, that is, infection score.…”

Epidemiology and Outcome Among Severe Sepsis and Septic Shock Patients in a South Indian Tertiary Care Hospital

“…The increased life expectancy of individuals (including those who are immune-compromised) and the surge seen with the utilization of invasive medical interventions are all important contributors to the high incidence of sepsis and its complications. International guidelines highlight the need for early identification of the condition and prompt implementation of the treatment, including antibiotics to reduce the serious consequences [8][9][10][11][12][13]. It has been observed that prompt administration of antibiotics and improve outcomes in patients with sepsis.…”