Presented at the Neonatal Society 2012 Spring Meeting.

Babarao S, Miall L, Newell S

Leeds Teaching Hospitals NHS Trust

Background: Clinical diagnosis of bacterial infection and sepsis in the neonatal population has always been a challenging task for neonatologists because of vague symptoms and signs and limitations of diagnostic tests currently available. Recent studies have suggested that Interleukin-6 assays can be useful in diagnosis of sepsis alongside other routine biochemical tests like CRP. Point-of-care Interleukin-6 assays (1) have been used in Leeds Teaching Hospitals (since Jan 2010) to enhance the rapid diagnosis of neonatal sepsis. 

Methods: A prospective web-based questionnaire survey of junior doctors (neonatal trainees) was carried out, followed by focus group discussion with experts (Consultants) working in neonatal medicine. Both the groups were administered 20 different hypothetical clinical scenarios of neonatal sepsis along with IL-6 and CRP results. The differences in diagnostic certainty of sepsis on the basis of clinical history alone were compared with that of addition of CRP and IL-6 results, within and between both the trainee and expert groups. (Expert group consensus responses were considered as gold-standard).

Results: 31 trainees (78%) responded to the online survey. 5 consultants took part in the focus group discussion.
Experts: Based on clinical history, CRP and IL-6 results, experts agreed to the possibility of sepsis in only 25% of the clinical situations. 11 scenarios were decided as equivocal even after the availability of history and test results. Antibiotic usage by experts subsequent to sepsis categorisation was reduced with the availability of CRP results. (55% after IL-6 vs. 30% after CRP results)
Trainees: When compared to IL-6 results, CRP results were shown to be statistically significant in changing decisions of sepsis in majority of clinical situations. Trainees favoured a greater likelihood of sepsis when IL-6 results were available prior to CRP results. But, CRP was more influential in changing the decisions of trainees irrespective of IL-6 results.
Using the focus group consensus as gold standard for sepsis categorisation, it was found that IL-6 results were used by trainees for confirming sepsis irrespective of whether they were available prior to or after CRP results. 

Conclusion: Both point-of-care IL-6 test results and CRP results helped doctors in confirming a diagnosis of sepsis. IL-6 was not useful in ruling out sepsis. CRP still seems to be interpreted by doctors with more confidence when compared to newer tests. Diagnosis of neonatal sepsis continues to be a challenging task for neonatologists. Interleukin-6 assays have to be used judiciously especially in ruling out sepsis in newborn infants.

Corresponding author: samik.hiran@gmail.com

References
1. Rees J. C-reactive protein or interleukin-6? Early diagnosis of neonatal sepsis. 2007; Available from: www.jrbiomedical.com.