In general, the signs and symptoms of illness are vague and nonspecific in neonates making the identification of specific diagnoses challenging. The survival of premature infants has produced a population of children whose corrected gestational age (chronological age since birth in weeks minus the number of weeks of prematurity) makes them, in many ways, similar to neonates. Neonates present to the emergency department (ED) with conditions ranging from normal to critical.
WEIGHT GAIN, FEEDING, AND STOOLING
Bottle-fed infants generally take 6 to 9 feedings (2 to 4 oz) in a 24-hour period, with a relatively stable pattern developing by the end of the first month of life. Breast-fed infants generally prefer feedings every 1 to 3 hours. Infants may lose up to 12% of their birth weight during the first 3 to 7 days of life. After this time, infants are expected to gain about 1 oz/d (20 to 30 g/d) during the first 3 months of life. Parental perception that an infant's food intake is inadequate may prompt an ED visit. If the patient's weight gain is adequate and the infant appears satisfied after feeding, parental reassurance is appropriate.
Regurgitation occurs when gastric contents are effortlessly expelled, typically within 30 minutes of feeding, and, though potentially large in volume, are never projectile or bilious. Regurgitation is typically a self-limited condition and if an infant is thriving and gaining weight appropriately, reassurance is appropriate.
Vomiting is differentiated from regurgitation by forceful contraction of the diaphragm and abdominal muscles. Vomiting has a variety of causes and is rarely an isolated symptom. Etiologies are diverse and include increased intracranial pressure (e.g., nonaccidental trauma), infections (e.g., urinary tract infections, sepsis, or gastroenteritis), hepatobiliary disease (usually accompanied by jaundice), and inborn errors of metabolism (usually accompanied by hypoglycemia and metabolic acidosis). Bilious vomiting in a neonate or infant should be considered a surgical emergency with particular concern for malrotation with midgut volvulus.
The number, color, and consistency of stool in the same infant changes from day to day and differs among infants. Normal breast-fed infants may go 5 to 7 days without stooling or have six to seven stools per day. Color has no significance unless blood is present, or the stool is acholic (i.e., white).
Infants without normal stooling in the first 2 days of life may have anatomic anomalies (e.g., intestinal stenosis or atresias), cystic fibrosis, Hirschsprung disease, or meconium ileus or plug. Constipation that develops later in the first month of life suggests Hirschsprung disease, hypothyroidism, anal stenosis, or anterior anus. Although bacterial infection may cause bloody diarrhea, this is rare in neonates. The most common cause of blood in the stool in neonates is anal fissures. Breast-fed infants may have heme-positive stool from swallowed maternal blood due to bleeding nipples. Necrotizing enterocolitis may present as bloody diarrhea and usually presents with other signs ...