Paediatric Surgery Essentials
When a tiny preterm baby in our neonatal intensive care unit (NICU) has an intestinal perforation, it is always necrotizing enterocolitis (NEC), right? Not so fast, my friend. Many of these preterm infants who perforate have free air from spontaneous intestinal perforation (SIP) and not NEC. As it turns out, not all free air in the NICU is NEC. How can you tell the difference and does it matter?
It can be challenging to tell the difference, but SIP tends to occur earlier in life, often within the first week, whereas NEC usually occurs slightly later. One analysis of a large data set showed the median age of onset of SIP was seven days after birth versus 15 days for NEC (1). SIP often occurs in babies who have never been fed or have only had trophic feeds, while many babies who develop NEC have had significant amounts of enteral nutrition or are on full feeds. SIP often presents with a relatively sudden onset of abdominal distention, not uncommonly with associated hypotension. NEC patients are more likely to have feeding intolerance or bloody stools noted before progressing to intestinal perforation.
Holtrop P, Khandar P, Novotny N. Not all free air in the NICU is necrotizing enterocolitis. Paediatric Surgery Essentials, 2020.