Biochemical markers of neonatal sepsis: value of procalcitonin in the emergency setting.

Background: We evaluated procalcitonin (PCT) assay in the emergency diagnosis of neonatal bacterial infection, especially in preterm infants, relative to C-reactive protein (CRP) and fibrinogen.

Methods: One hundred and twenty neonates (32 preterm), of whom 21 were infected, were tested.

Results: Concentrations of PCT, CRP and fibrinogen in uninfected infants were not affected by gestational age at birth. Concentrations of CRP and PCT increased rapidly during the first 24 h of life, while fibrinogen concentrations increased gradually from birth. All marker concentrations were significantly greater in neonates with bacterial infection. Receiver-operating characterstic analysis showed that optimum cut-off values for fibrinogen, CRP and PCT were 3.0 g/L, 7.5 mg/L and 2.5 microg/L respectively, for the diagnosis of sepsis at birth.

Conclusions: Determination of PCT is of value in excluding bacterial infection in neonates since it has a negative predictive value of 93%.