Necrotizing Enterocolitis – Top USMLE Diseases

In the pediatric population, imaging often plays a critical diagnostic role, especially in diagnosing congenital anomalies. In children, CT scans are avoided if at all possible due to the high risk of radiation exposure. In addition, both CT and (especially) MRI require children to hold still for significant periods of time and often require sedation to complete the study. For these reasons, plain radiography (often with contrast), fluoroscopy, and ultrasound are the imaging modalities of choice for most suspected cases involving GI pathology. Some conditions that can be diagnosed using imaging include hypertrophic pyloric stenosis, necrotizing enterocolitis, midgut malrotation with or without volvulus, intestinal atresia intussusception, appendicitis, Hirschsprung disease, mesenteric lymphadenitis, and obstructions of the biliary tree.

Respiratory distress syndrome (RDS), also known as hyaline membrane disease, is caused by the lack of adequate pulmonary surfactant production in an immature lung. The syndrome is most commonly seen in preterm infants. The incidence is inversely related to gestational age, with the highest risk in neonates born at less than 28 weeks. Prenatal assessment of lung maturity and steroid administration can improve outcome if an early delivery cannot be prevented. Diagnosis is clinical. Affected newborns show signs of respiratory distress at birth, or soon thereafter, with nasal flaring, grunting respirations, and retractions. Treatment includes antenatal steroids, exogenous surfactant, and respiratory support. Neonatal RDS is associated with high morbidity and mortality in preterm infants.

Necrotizing enterocolitis (NEC) is an intestinal inflammatory process that can lead to mucosal injury and necrosis. The condition is multifactorial, with underlying risk factors that include prematurity and formula feeding. The clinical presentation varies in severity from feeding intolerance, acute findings on abdominal exam, and systemic symptoms. The diagnosis is based on a clinical suspicion, abnormal abdominal radiographs, and supporting abnormal laboratory results. Management consists of supportive medical care for milder stages and bowel rest and surgical intervention for more advanced stages. Necrotizing enterocolitis and its complications carry a high risk of morbidity and mortality.