Prognostic value of C-reactive protein in neonatal sepsis

Abstract

Background: Infection is one of the major problems in neonates. The diagnosis of neonatal septicemia is difficult to establish based on the clinical criteria alone. Empirical treatment should not be delayed because of the high mortality. Blood cultures are considered the gold standard for diagnosis of neonatal sepsis. Creactive protein (CRP) is an acute phase protein found in the blood, the levels of which rise in response to inflammation. During the acute phase response, levels of CRP rapidly increase within 2 hours of acute insult, reaching a peak at 48 hours. Objective: To investigate the diagnostic value of CRP. To show the benefit of doing serial measurement of CRP in neonatal sepsis in providing additional support for the observation and follow up of patient with sepsis. To show the prognostic meaningful of CRP in neonatal sepsis. Methods: A hospital-based cross sectional study design was conducted in Mosul over one year period from the 1 st of Nov. 2010 to the 30 th of Oct. 2011. A total of 198 neonates aged 1-28 days who were admitted to pediatrics wards in Al-Khansaa Teaching Hospital in Mosul during the study period under provisional diagnosis of sepsis and had a positive C-reactive protein level >6 mg/l were included in the study. All patients were sent for blood culture, and the final diagnosis of sepsis depended on the result of blood culture. Results: Male gender constituted 63.5% of patients with sepsis compared to 51% patients without sepsis. Refusal to feed and tachypnea were the most frequent complaints in both groups (sepsis and no sepsis). All patients at admission had high CRP while only 52% had culture-proven sepsis. After 72 hrs of admission, CRP was still high in approximately half of the patients after receiving treatment but only 62% of them had positive blood culture. Higher initial CRP titer constituted 40.4% of the sepsis group compared to only 23.4% of no sepsis group, the difference was significant (p=0.009). CRP levels between 6 mg/L and 12 mg/L were more frequently observed among no sepsis than in sepsis groups (14.4% and 37.2% respectively). In patients with CRP ≥40 mg/L, CRP was significantly higher in patients with blood culture positive than in patients with suspected sepsis but negative blood culture, and after 72 hours of treatment high levels of CRP still constituted 60.6% of cases with proven sepsis compared to 46% among the suspected sepsis group but with negative blood culture. Death rate was 5% and E. coli was the predominant microorganism isolated. Conclusion: Gram-negative microorganisms are a predominant cause of neonatal sepsis in our community. Predictive value of CRP could be enhanced by serial rather than a single measurement. A high cut off value of CRP may be needed to diagnose neonatal sepsis.