**2. Sepsis in emergency department**

Sepsis is a complex clinical syndrome that still represents a major challenge for today's medicine. In fact, despite the current possibilities of treatment, sepsis remains burdened by a high prevalence in the population and above all by a severe prognosis, representing one of the pathologies with the highest rate of morbidity and mortality. It is responsible for about onethird of all hospital admissions, and about 50% of ICU admissions. Mortality would reach 40%, of which 25% of deaths would occur within 48 h of entry into ICU [8].

**4. Clinical scores**

assess the risk of mortality [12].

discrimination and calibration [13].

tings, primarily in emergency medicine.

sion already on arrival in the emergency room [16].

Since 2004, worldwide, the "Surviving Sepsis Campaign", consisting of a multidisciplinary team of specialists, periodically deals with the preparation and updating of documents on the general management of the septic patient and some specific aspects, such as timing and the optimal choice of antibiotic therapy, blood pressure support, glycemic control and oxygenation. In particular, at the last revision, the bundle of measures are implemented within the

Biomarkers Utility for Sepsis Patients Management http://dx.doi.org/10.5772/intechopen.76107 61

At the same time, over the years, the need arose, especially in an intensivist environment, to identify those factors capable of predicting clinical severity and, in particular, the risk of death; for this purpose, many patient severity scores have been proposed and validated, useful from the moment of diagnosis to stratify the patient's clinical severity and, indirectly, to

The ideal prognostic score should have high sensitivity and high predictive value, be able to predict early mortality or clinical evolution, be rapidly usable, available everywhere, economic, objective and non-observer-dependent. Currently, no clinical score has all these characteristics. In particular, the two basic requirements of a prognostic system are the power of

There are several works that have evaluated in the emergency medicine settings, the applicability of different gravity scores. In particular, simpler models to be calculated than those commonly used in Intensive Care Unit (ICU) have been proposed [11]. In 2003, Shapiro et al. have proposed the adoption of a new prognostic model, called Mortality in Emergency Department Sepsis (MEDS), as a method for stratifying patients afferent in emergency medicine with suspected sepsis [14]. Sankoff et al. resumed the MEDS score and carried out a multi-center prospective study to verify its reproducibility and validity [15]. The MEDS is the only score designed to be used in the septic patient in settings different from ICU. Numerous prognostic models born to be used in ICU were subsequently applied in different care set-

In one of the best known studies, Jones et al. have proposed the adoption of the Sequential Organ Failure Assessment (SOFA) score as a tool to predict the outcome of patients with severe sepsis with signs of hypoperfusion or septic shock. The authors considered all patients over the age of 18 with sepsis and evidence of hypoperfusion (systolic BP <90 mmHg or lactate levels>4 mmol/L); calculated the SOFA score at time zero and after 72 h (delta SOFA). The outcome of the study was to evaluate in-hospital mortality, the possible correlation between the difference in SOFA between admission and after 72 h, and finally mortality. The authors have shown a good correlation between the SOFA score at the entrance and the delta SOFA with the risk of in-hospital mortality. The limit of the work, similar to the studies on the MEDS score, is that it is an experience conducted only in a single center, which should be validated and extended to several centers to obtain a useful risk assessment tool [16, 17]. Alan E Jones et al. also demonstrated the usefulness of SOFA as a predictive prognosis score in patients with sepsis, and in particular in patients with severe sepsis with signs of hypoperfu-

first hours after admission of the patient to reduce mortality was well defined [11].

In this complex scenario, the emergency doctor plays a key role. In fact, it depends on early diagnosis and treatment, the two factors that are recognized today as fundamental in the correct management of the septic patient as it is able to improve the prognosis. The enigmatic and often heterogeneous nature of sepsis, the absence of specific clinical and laboratory elements causes the lack of valid diagnostic tools, strongly influencing early intervention [9].

The recent literature has therefore placed great attention in the search for all clinical and laboratory factors, which can help in the rapid identification of sepsis and in the stratification of the risk of such patients, in order to make the treatment as aggressive as possible in terms of timeliness and effectiveness. More than two decades ago, sepsis was defined by the combination of an SIRS and an infection. This criterion, therefore useful for the correct diagnosis of sepsis, is also endowed with prognostic capacity, proving to be effective for the gravity stratification of patients with suspected infection due to the linking of these criteria with the presence of organ damage. However, the role of SIRS has been recently revised because although it has high prognostic power, it has little specificity being involved in a wide variety of pathologies regardless the presence of infection, in which the differential diagnosis often becomes difficult. Furthermore, it has been calculated that a certain number of patients with sepsis may not present SIRS criteria (about 1 in 8) [10]. The "Third International Consensus Definitions for Sepsis and Septic Shock" (Sepsis-3) [7] has therefore decided to go beyond the concept of SIRS, emphasizing rather the role of the organism's response to infection and organ damage (identified by a SOFA value ≥2) in the pathogenesis of sepsis.
