Outcome of CSF Analysis in Babies with Elevated CRPs but Clinically Well Dr Charlotte Davidson, Dr David Deekollu Prince Charles Hospital, Cwm Taf University Health Board

Background Early-onset neonatal bacterial infection (infection with onset within 72 hours of birth) is a significant cause of mortality and morbidity in newborn babies. In industrialised countries, the incidence of bacterial meningitis is approximately 0.3 per 1000 live births

NICE Guidelines Regarding CRP Monitoring: Measure the C-reactive protein (CRP) concentration at presentation when starting antibiotic treatment in babies with risk factors for infection or clinical indicators of possible infection. In babies given antibiotics because of risk factors for infection or clinical indicators of possible infection, measure the CRP concentration 18–24 hours after presentation. Regarding Lumbar Punctures: Consider performing a lumbar puncture (LP) to obtain a cerebrospinal fluid sample in a baby who is receiving antibiotics, if it is thought safe to do so and if the baby: has a CRP concentration of 10 mg/litre or greater, or has a positive blood culture, or does not respond satisfactorily to antibiotic treatment

Aim Investigate the outcome of LPs in clinically well newborn babies with CRP level of 10mg/l or greater. Assess need to review the threshold for LP in this group of clinically well babies.

Method Retrospective case notes review of newborn babies who had significant risk factors for sepsis, were screened with CRP and blood culture and received prophylactic antibiotics. This study included only those babies who were clinically well and had elevated CRP levels above 10mg/l.

Data Collection Initially I collated data of all newborn babies with a CRP 10mg/l or greater over this period. I then reviewed the indication for the CRP check and reviewed if a lumbar puncture was carried out - in accordance with the guidelines and the laboratory results. 66 newborn babies had a CRP 10mg/l or greater from December 2013 to January were discarded due to incomplete medical records, so 59 were included in the study.

Results: Indications for CRP Out of the 59 subjects results were separated into clinically well and clinically unwell. 27 (46%) were clinically well when the initial CRP was taken.

Results: CSF Results Out of the 59 newborn babies with a CRP >10, 42 lumbar punctures were performed. In 8 cases lumbar puncture was not attempted and 9 failed to obtain a sample. Of the 42 lumbar punctures 7 samples were unsuitable for analysis (17%). From the 16 clinically well babies who had LP: Normal CSF result and no organisms were grown in all cases

Conclusions Clinically well newborn babies with CRP elevated above 10 mg/l had normal CSF results. No organisms were grown in any of the CSF samples for the LPs taken during this period. In newborn babies with a CRP >10 71% had an LP. We recommend further review of the CRP threshold for the routine lumbar puncture for clinically well newborn babies.

Acknowledgements Dr David Deekollu, Consultant Paediatrician, Prince Charles Hospital - Project supervisor Professor John Geen - Consultant Clinical Biochemist for supplying the CRP results of all newborn babies with a CRP >10 Lauren Dyton - Clinical Audit Officer, Prince Charles Hospital Paediatric Department at Prince Charles Hospital

References Davies PA, Rudd PT. Incidence; The Developing Brain. Neonatal Meningitis. Cambridge, England: Cambridge University Press; Ch 1 NICE Guidelines: CG149: Antibiotics for early-onset neonatal infection: Antibiotics for the prevention and treatment of early- onset neonatal infection

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