Poor feeding and feeding intolerance in the neonate — formative SAQs

SAQ 1 (10)

A 12-day-old infant born at 27 weeks' gestation, weighing 920 g, is on advancing expressed breast milk feeds at 120 mL/kg/day. The nurse reports that the pre-feed gastric residual is now larger than the feed volume and is bile-stained, the abdomen looks fuller, and the infant has had three apnoeic spells requiring stimulation. [1] [3]

1. Interpret these findings and state the most likely diagnosis to exclude. (3) [1]
2. Outline your immediate management. (4) [3]
3. Describe the investigation that confirms the diagnosis and the findings you seek. (3) [3]

Model answer

1. These findings are feeding intolerance with systemic signs in an extremely preterm infant — necrotising enterocolitis until proven otherwise. The increasing and bile-stained residual, abdominal distension, and new apnoea are the systemic and gastrointestinal signs of early NEC. A bilious residual also raises a surgical obstruction, but in this preterm the context makes NEC the leading diagnosis to exclude. [1]
2. Stop feeds (nil by mouth), pass a large-bore orogastric or nasogastric tube on free drainage to decompress the gut, establish intravenous access, resuscitate with isotonic crystalloid boluses (10 mL/kg) titrated to perfusion, correct glucose and temperature, and start broad-spectrum empiric antibiotics covering Gram-positive and Gram-negative enteric organisms. Escalate to the neonatal team and, in a rural setting, activate retrieval. [3]
3. A plain abdominal radiograph (anteroposterior, plus a left-lateral-decubitus or cross-table-lateral view) confirms NEC when it shows pneumatosis intestinalis (gas in the bowel wall — the hallmark), portal venous gas, or a persistently dilated loop. Free intra-abdominal gas indicates perforation. The laboratory panel (full blood examination for thrombocytopenia, C-reactive protein, blood gas for metabolic acidosis, glucose, blood cultures) grades the severity. [3]

SAQ 2 (10)

A two-day-old term infant vomits green fluid twice and has fed poorly since birth. The abdomen is soft and non-distended. [3]

1. What is the significance of bilious vomiting in a neonate, and which diagnosis must be excluded as a priority? (3) [3]
2. Outline your immediate assessment and management. (4) [3]
3. Explain the evidence supporting human milk over formula for reducing necrotising enterocolitis risk in preterm infants. (3) [6]

Model answer

1. Bilious (green) vomiting in a neonate means obstruction below the ampulla of Vater and is a surgical emergency until proven otherwise. The priority diagnosis to exclude is malrotation with midgut volvulus, because the cost of delay is loss of the midgut; duodenal or jejunoileal atresia, Hirschsprung disease, and annular pancreas are also in the differential. A soft, non-distended abdomen does not exclude volvulus — the radiograph may look deceptively normal early. [3]
2. Resuscitate: make nil by mouth, decompress the stomach, establish intravenous access, give fluid and empiric antibiotics. Refer urgently to the paediatric surgical team. Investigate with an upper gastrointestinal contrast study (looking for an abnormal position of the duodenojejunal flexure, a 'corkscrew' or 'beak' sign) once the infant is stable enough — but do not delay the surgical referral for the study. [3]
3. The Cochrane review by Quigley and Embleton (2019) found that feeding preterm or low-birth-weight infants formula rather than donor breast milk increases the risk of necrotising enterocolitis. Mother's own milk is first-line because it delivers secretory immunoglobulin A, lactoferrin, growth factors and human milk oligosaccharides that mature the mucosal barrier and shape a protective microbiome; donor milk retains much of this protection. This is the foundation of the 'mother's own milk first, donor milk second, formula last' hierarchy. [6]