BACKGROUND INTRODUCTION

Neonatal sepsis is a significant cause of morbidity and mortality in newborn infants. The precise identification of neonatal sepsis still remains a diagnostic conundrum. Neonates with suspected sepsis are treated empirically with antibiotics. This however promotes the unnecessary use of antibiotics which is costly, increases antibiotic resistance, and alters the delicate neonatal gut microbiota.

Enhancing the accuracy of diagnostic tests will aid in the early identification and improve the outcomes for neonates with sepsis and will reduce the indiscriminate administration of antimicrobials in those who don’t. Biomarkers aid in the diagnosis of sepsis, with the most commonly used being C-reactive protein (CRP). CRP however lacks specificity and the response to bacteremia is slower1

Promising evidence supporting the use of procalcitonin (PCT) in neonatal sepsis has been shown to identify sepsis earlier. A PCT rise identifies more severe sepsis2 and has a good diagnostic accuracy3. Hence the addition of PCT to CRP improves antimicrobial stewardship4. Despite the evidence, PCT is not commonly used in the neonatal population.

Aims

To evaluate the use of PCT in all babies older than 72 hours of age, who need to be screened for suspected

Late Onset Neonatal Sepsis (LONS).

Methodology

Babies with clinical signs of LONS were screened and started on antibiotics as per the neonatal unit’s protocol –PCT was added to the investigations.

PCT was requested alongside the 1st and 2nd (24h) CRP and in the same blood bottle to avoid extra blood sampling.

Pdsa Cycles

Cycle 1: We studied the root cause analyses (RCA) of Klebsiella Pneumoniae and Escherichia Coli cases over six years (20152021).

Prematurity, low birth weight (LBW), mechanical ventilation, central lines, parenteral nutrition, multiple antibiotic courses, and abdominal pathology requiring surgery were risk factors for both cohorts.

Cycle 2: The total number of antibiotic courses for suspected LOS over three months were analysed. Results were presented and the temporary introduction of PCT with 1st and 2nd CRPs was decided to review the enzyme response in LOS. Posters were created to raise awareness.

A Klebsiella Pneumoniae outbreak in our neonatal unit triggered a review of the specific risk factors for Gram Negative Blood Stream Infections (GNBSI). Amongst others, multiple courses of antimicrobials in the preterm population significantly contributed to the problem. A collaborative Quality Improvement PCT Group was initiated to review the use of PCT in reducing antibiotic exposure in neonates.

Cycle 3:

After liaising with the local microbiology department, a sevenweek audit (1/11/202218/12/2022) of 43 antibiotic courses was initiated and completed. 10 out of 43 episodes (23%) had no PCT available; either due to insufficient sample or because it was forgotten. Hence 33 cases (77%) were reviewed. PCT results were reviewed (normal value < 0.5 ng/ml).

Results Conclusion

• Neonates who received antibiotics for LOS between OctoberDecember 2021 (46 babies and 75 courses) had ‘true’ positive blood cultures (BC) in 15% of cases (11/75). There was a significant variation on length of treatment with 37% (28/75) of total cases receiving > 36 hours of antibiotics (Fig 1), ranging between 5-14 days.

• The analysis of the PCT audit showed results on 77% of episodes (33/43). 18/33 cases had 2 CRPs < 5 and negative blood cultures. 8/18 had 2 PCTs taken and 10/18 had 1 PCT taken. All PCTs were normal (Fig 2).

• 40% of cases (6/15) had a quicker PCT than CRP response and all six babies had confirmed sepsis with positive BC results (Fig 3).

• 2 neonates with overwhelming sepsis and subsequent death had the highest PCT in the cohort.

Our findings suggest that PCT is a sensitive and specific biomarker of infection. Giving the findings and ongoing concerns with regards to multiple antibiotic regimes, our practice will change and PCT will be requested with the 2nd CRP in cases of suspected LONS, with the aim to stop antibiotics within 24 hours on negative results prior to blood culture results.