Final answer:
To suspect hyperbilirubinemia in a large-for-gestational-age newborn, a nurse should look for signs of jaundice. The condition is caused by an accumulation of bilirubin due to insufficient processing by immature liver enzymes. Prompt phototherapy can effectively treat this potentially dangerous condition.
Step-by-step explanation:
A finding that would lead a nurse to suspect that a large-for-gestational-age newborn is developing hyperbilirubinemia is the observation of jaundice, which is characterized by a yellowish coloration of the skin and mucous membranes. This yellowing occurs when the concentration of bilirubin, a product of erythrocyte breakdown, exceeds the binding capacity of albumin and diffuses into tissues. Since newborns, especially large-for-gestational-age ones, can have increased erythrocyte breakdown and might not yet have a fully functional liver enzymatic system, including deficient UDP glucuronyl transferase activity, they can quickly accumulate excessive levels of unconjugated bilirubin. In severe cases, this can lead to kernicterus, resulting in potential brain damage. Therefore, it is crucial to monitor such infants for signs of hyperbilirubinemia and initiate treatment, such as phototherapy, to prevent these complications.