White Blood Cells and Platelets Indices as a Prognostic Factor in Neonatal Sepsis

"Suspected sepsis" is one of the most frequently encountered diagnosis in neonatology because: a) a large number of newborns are evaluated for early or late sepsis based on risk factors and for fear of missing a correct diagnosis and a prompt treatment ; b) in neonates, the clinical signs of infection are not specific, late, and the differential diagnosis with neonatal respiratory distress syndrome, aspiration syndromes or neonatal maladaptation to extra-uterine life is difficult ; c) blood culture - the golden standard in neonatal sepsis diagnosis - provides late information, has a poor accuracy, and is not universally available; and d) up to date, there is no an ideal diagnostic tool for neonatal infection . Therefore, diagnosis of neonatal sepsis is still a challenge for neonatal medicine.

Antibiotic therapy is often initiated based upon clinical suspicion and/or the presence of risk factors, leading to excessive antibiotic therapy. Very often the diagnosis criteria for neonatal sepsis consists in documenting an infection in a newborn with severe systemic disease in which all possible noninfectious explanations for the patient's altered physiological status are either ruled out or unlikely.

The "gold standard", definitive test for neonatal sepsis is the isolation of the pathogen from blood. However, its accuracy is influenced by multiple factors a) contamination during sampling; b) sampling after antibiotic therapy was started; c) insufficient sampling volume; d) low colony count bacteremia. Accuracy of the blood culture varies between8 and 73% in various studies .

Despite hundreds of published studies, there is still no consensus regarding the best screening test or panel of tests for rapid detection of neonatal sepsis. Recently, new acute phase proteins, cytokines, cell surface antigens, and bacterial genome are used to improve the neonatal sepsis diagnosis but data are still under evaluation and most of these tests are either not clinically available or they are expensive .

Accumulating evidence indicates that the CBC is an effective predictor of prognosis and mortality in many disease states, including hematological disease, neoplasms, and severe infections. Therefore, non- specific changes in the CBC in critically ill neonates could be considered a key prognostic factor in the evaluation of survival prediction in these patients .