P38 An audit of antibiotic use in the treatment of neonatal necrotising enterocolitis (NEC): what do we use and how long for?
Authors: Morris Stephen , Mak Kimberly , Lisseter Rebecca 
Published: August 2020

Introduction

Necrotising enterocolitis (NEC) is a serious condition in premature infants involving inflammation, and potentially necrosis, of the bowel. Several contributory factors have been identified; including prematurity, infection and reduced gut perfusion. 1 It has previously been reported that there is widespread variation in the treatment of NEC 2, including the use of antibiotics. 3 This is due to a lack of evidence evaluating which treatment option is most effective.

Optimising the use of antibiotics for treating NEC is an opportunity to support the wider, global initiative of antimicrobial stewardship.4 Ensuring we use only the necessary course of antibiotics will reduce the spread of resistance and lower risks of potential adverse effects. Our local NEC treatment guideline states that the first line antibiotic regimen should be amoxicillin, gentamicin and metronidazole for up to 10 days treatment.

Aim

The aim of our audit was to identify the type of antibiotics and the duration of therapy used to treat NEC within a single UK tertiary children’s hospital providing neonatal intensive care and neonatal surgery.

Methods

A retrospective audit was conducted over a five month period between August and December 2018. The neonatal database (Badger®) was used to identify patients with a confirmed diagnosed of NEC. Our electronic prescribing software (MedChart®) along with patient medical notes was then used to determine the antibiotics used and the prescribed length of treatment. A re-audit was also conducted over a 5 month period between January and May 2019.

Results

We identified seven patients with confirmed diagnosis of NEC. The median gestational age was 30+6 weeks (range 29+4 to 36+1 weeks) and the median birth weight was 1530 grams (range 780 to 2100 grams). Four patients required surgery that involved laparotomies and bowel resections. No patients had allergies to penicillins.

The most frequently prescribed antibiotic regimen was ceftazidime, vancomycin and metronidazole (n=4). Other regimens included meropenem and vancomycin (n=2), and amoxicillin, gentamicin and metronidazole (n=1). The median course length was 10 days (range 2 to 16 days). These results were presented to a neonatal surgery quality improvement meeting in January 2019.

During the re-audit period, five infants were identified. The median gestation was 28+3 weeks (26+1 to 37+0 weeks) and median birth weight of 1310 grams (range 620–2090 grams). 3 patients had laparotomies and none had allergies to penicillins. In this cohort, the most popular regimen was amoxicillin, gentamicin and metronidazole (n=4), followed by ceftazidime, vancomycin, and metronidazole (n=1). The median course length was 11 days (range 5 to 12 days).

Conclusion

Our initial audit confirmed that considerable variation still exists in the antibiotic regimen used and the duration of treatment. We also found that patients were frequently not treated according to the local guideline. The initial audit results were used to highlight the issue to our surgical and neonatal teams. After the re-audit, it is clear that this approach improved the compliance with the guideline in terms of which antibiotics were used. However, we also found that the duration of treatment still varied considerably.

References

Neu, J. and Walker, W.A. Necrotizing Enterocolitis. New England Journal of Medicine. 2011;364:255–264.

Zani A, Eaton S, Puri P, et al. International Survey on the Management of Necrotizing Enterocolitis. Eur J Pediatr Surg. 2015;25:27–33.

Blackwood, B.P., Hunter, C.J. and Grabowski, J. Variability in Antibiotic Regimens for Surgical Necrotizing Enterocolitis Highlights the Need for New Guidelines.Surgical Infections 18:215–220

World Health Organisation. Global action plan on antimicrobial resistance. [Online]. 2015. [Accessed 24th June 2019]. Available from: http://www.who.int/antimicrobial-resistance/global-action-plan