A nurse is caring for an infant who is receiving phototherapy. Which of the following findings requires intervention by the nurse?

Choice A reason: Physiological jaundice is not the correct answer, as it is a normal and benign condition that occurs in about 60% of term newborns, and usually appears after the first 24 hours of life. Physiological jaundice is caused by the breakdown of fetal hemoglobin and the immature liver function, and resolves within a few days.

Choice B reason: Maternal cocaine abuse is not the correct answer, as it is a maternal risk factor that can cause various complications in the newborn, such as low birth weight, prematurity, intrauterine growth restriction, or congenital anomalies. Maternal cocaine abuse does not cause jaundice in the newborn, unless it leads to hepatic or renal dysfunction.

Choice C reason: Maternal/newborn blood group incompatibility is the correct answer, as it is a maternal-fetal condition that can cause hemolytic disease of the newborn, which is a severe form of jaundice that can appear within the first 24 hours of life. Maternal/newborn blood group incompatibility occurs when the mother's blood type is Rh negative and the newborn's blood type is Rh positive, or when the mother's blood type is O and the newborn's blood type is A or B. The maternal antibodies cross the placenta and attack the newborn's red blood cells, causing hemolysis, anemia, and hyperbilirubinemia.

Choice D reason: Absence of vitamin K is not the correct answer, as it is a nutritional deficiency that can cause hemorrhagic disease of the newborn, which is a bleeding disorder that can occur within the first week of life. Absence of vitamin K is due to the lack of intestinal flora and the low vitamin K content in breast milk, and can cause bleeding in the skin, mucous membranes, or internal organs. Absence of vitamin K does not cause jaundice in the newborn, unless it leads to hepatic or biliary dysfunction.

Choice A reason: Providing a dark, quiet environment is an appropriate action for the nurse to implement, because it can help reduce the client's blood pressure and prevent seizures.

Choice B reason: Evaluating neurologic status every 12 hr is not an appropriate action for the nurse to implement, because it is not frequent enough. The nurse should assess the client's neurologic status every 2 to 4 hr, or more often if indicated, to detect signs of cerebral edema or eclampsia.

Choice C reason: Assessing respiratory status every 8 hr is not an appropriate action for the nurse to implement, because it is not frequent enough. The nurse should monitor the client's respiratory status every 1 to 2 hr, or more often if indicated, to detect signs of pulmonary edema or respiratory depression.

Choice D reason: Ensuring that calcium gluconate is readily available is an appropriate action for the nurse to implement, because it is the antidote for magnesium sulfate toxicity. The nurse should have calcium gluconate on hand and know how to administer it in case of an emergency.

Choice E reason: Administering magnesium sulfate IV is an appropriate action for the nurse to implement, because it is the drug of choice for preventing and treating seizures in clients with severe gestational hypertension. The nurse should follow the protocol for magnesium sulfate administration and monitor the client's vital signs, urine output, reflexes, and serum magnesium levels.