Interval between clinical presentation of necrotizing enterocolitis and bowel perforation in neonates.

Objective: To define the interval between clinical presentation of necrotizing enterocolitis (NEC) and bowel perforation in neonates.

Methods: Charts of neonates with discharge diagnosis of NEC (n = 124) from our NICU during 2004-2008 were retrospectively reviewed. Demographic data were collected. Acute episode of NEC was defined as the interval between clinical presentations to resumption of enteral feeds. Neonates are followed, as a standard of care, clinically and radiologically until resumption of enteral feeds at the discretion of the attending clinician. Abdominal radiograph results were reviewed serially to determine the interval between clinical presentation and bowel perforation using pneumoperitoneum as the surrogate radiological marker. Histological report of resected bowel specimens was reviewed for coagulative necrosis as evidence of NEC and to exclude spontaneous intestinal perforation (SIP). Neonates with stage 1 NEC and SIP were excluded from the results.

Results: 105 neonates with stage 2 NEC were included in the study. Forty-six needed surgical treatment (group 2) and 59 did not need surgery (group 1). Twenty-six (26/46, 56%) group 2 neonates had bowel perforation and hence required surgery. Pneumoperitoneum was noted at a median interval of 1 day after presentation of symptoms. Twenty neonates in group 2 needed surgery for clinical indications including worsening clinical examination, thrombocytopenia or persistent metabolic acidosis. Fifty-nine neonates (group 1) were treated with bowel rest, antibiotics and parenteral nutrition. Group 2 neonates were significantly more premature, weighed less and had less radiographs than group 1 neonates. Mortality was significantly higher in group 2 compared to group 1.

Conclusion: Bowel perforation occurs at a median interval of 1 day after clinical presentation of NEC. Neonates not needing surgery for their disease are exposed to significantly more radiographs than those needing surgery. Radiological evaluation can be safely minimized or eliminated after 2 days of presentation.