Necrotising enterocolitis (NEC) — base rate in extreme prematurity
The prosecution’s claim: Bowel-gas findings on imaging and post-mortem in several indicted infants were treated as evidence of deliberate air injection rather than as evidence of natural disease.
Prosecution claim
Bowel-gas findings on imaging and post-mortem in several indicted infants were treated as evidence of deliberate air injection rather than as evidence of natural disease.
Counter-evidence
Necrotising enterocolitis (NEC) affects approximately 7-10% of infants born under 1500g birthweight and carries 20-30% mortality. NEC is the leading cause of gastrointestinal emergency in preterm neonates and is independently associated with hepatic portal venous gas — the imaging finding the prosecution treated as proof of deliberate air injection. The Crown's mechanism required that bowel gas had been deliberately introduced. Two things answer that without a deliberate act. First, natural disease: the Shoo Lee Panel's finding for Child Q is early NEC or sepsis. Second, the treatment itself: the Panel concluded that the '++ air' aspirated from Child Q's nasogastric tube was most likely introduced by the bag-and-mask ventilation that preceded the aspiration, and that every X-ray showing gaseous distension in Child G was taken after bag-and-mask ventilation had been given. It found no evidence of air injection in either case.
Key point: Hepatic portal venous gas in an extremely preterm infant is the textbook radiological signature of necrotising enterocolitis. And air in a stomach that has just been bagged was put there by the bagging. Reaching for a deliberate-injection mechanism before excluding either inverts the diagnostic hierarchy.
What the jury heard
Bowel-gas findings were presented as corroborative of the prosecution's air-injection mechanism. The NEC base rate, and the fact that bag-and-mask ventilation itself fills the stomach with air, were not given equal weight as competing explanations.
What the Panel says
The Panel identifies early NEC or sepsis as the picture in Child Q, and concludes the air aspirated from Child Q's nasogastric tube was most likely introduced by the bagging that preceded it. It makes the same point about Child G, where every gaseous-distension X-ray was taken after bag-and-mask ventilation. It found no evidence of air injection in either case.
What independent experts add
- Independent paediatric gastroenterologists who have reviewed the prosecution mechanism have noted that NEC must be the differential of first choice for the imaging findings.
- Bag-and-mask ventilation inflates the stomach as well as the lungs; a film or an aspirate taken afterwards will show air that the resuscitation put there.
- Post-mortem gas redistribution as an artefact further confounds the imaging picture in cases where examination is delayed.
- Our /analysis/coagulopathy-dic-differential page covers the related coagulopathy-of-prematurity differential.