Preventive strategies and factors associated with surgically treated necrotising enterocolitis in extremely preterm infants: an international unit survey linked with retrospective cohort data analysis

Abstract

Objectives: To compare necrotising enterocolitis (NEC) prevention practices and NEC associated factors between units from eight countries of the International Network for Evaluation of Outcomes of Neonates, and to assess their association with surgical NEC rates.

Design: Prospective unit-level survey combined with retrospective cohort study.

Setting: Neonatal intensive care units in Australia/New Zealand, Canada, Finland, Israel, Spain, Sweden, Switzerland and Tuscany (Italy).

Patients: Extremely preterm infants born between 24⁰ to 28⁶ weeks' gestation, with birth weights<1500 g, and admitted between 2014-2015.

Exposures: NEC prevention practices (probiotics, feeding, donor milk) using responses of an on-line pre-piloted questionnaire containing 10 questions and factors associated with NEC in literature (antenatal steroids, c-section, indomethacin treated patent ductus arteriosus and sepsis) using cohort data.

Outcome measures: Surgical NEC rates and death following NEC using cohort data.

Results: The survey response rate was 91% (153 units). Both probiotic provision and donor milk availability varied between 0%-100% among networks whereas feeding initiation and advancement rates were similar in most networks. The 9792 infants included in the cohort study to link survey results and cohort outcomes, revealed similar baseline characteristics but considerable differences in factors associated with NEC between networks. 397 (4.1%) neonates underwent NEC surgery, ranging from 2.4%-8.4% between networks. Standardised ratios for surgical NEC were lower for Australia/New Zealand, higher for Spain, and comparable for the remaining six networks.

Conclusions: The variation in implementation of NEC prevention practices and in factors associated with NEC in literature could not be associated with the variation in surgical NEC incidence. This corroborates the current lack of consensus surrounding the use of preventive strategies for NEC and emphasises the need for research.

Keywords: neonatology; paediatric gastroenterology; paediatrics; perinatology.

Figure 1

Routine start of enteral feeding for extremely preterm infants. Bubble chart displaying routine start of enteral feeding for network infants<26 weeks’ gestation and 26–28 weeks’ gestation. Circle size corresponds to proportion of units per network with routine start of enteral feeding at any given day. ANZNN, Australian and New Zealand neonatal network; CNN, Canadian Neonatal Network; FinMBR, Finnish medical birth register; GA, gestational age; INN, Israel Neonatal Network; PD, physician dependent; SEN1500, Spanish neonatal network; SNQ, Swedish Neonatal Quality Register; SwissNeoNet, Swiss neonatal network; TuscanNN, Tuscan neonatal network.

Figure 2

Necrotising enterocolitis surgery prevalence rate and 95% CI by network for 2014–2015. ANZNN, Australian and New Zealand neonatal network; CNN, Canadian Neonatal Network; FinMBR, Finnish medical birth register; INN, Israel Neonatal Network; NEC, necrotising enterocolitis; SEN1500, Spanish neonatal network; SNQ, Swedish Neonatal Quality Register; SwissNeoNet, Swiss neonatal network; TuscanNN, Tuscan neonatal network.

Figure 3

Standardised ratios for surgically treated necrotising enterocolitis from 2014 to 2015. Standardised ratios were adjusted for: gestational age, male sex, multiple birth and birth-weight z-score. abbreviations: ANZNN, Australian and New Zealand neonatal network; CNN, Canadian Neonatal Network; FinMBR, Finnish medical birth register; INN, Israel Neonatal Network; SEN1500, Spanish neonatal network; SNQ, Swedish Neonatal Quality Register; SwissNeoNet, Swiss neonatal network; SR, standardised ratio; TuscanNN, Tuscan neonatal network.