A nurse is caring for a preterm newborn who has hypoglycemia due to inadequate gluconeogenesis.

The nurse should understand that this condition occurs because preterm newborns have limited stores of which of the following substances?

The correct answer is choice B. Check if there is any cross-sensitivity between erythromycin and penicillin.Erythromycin is a macrolide antibiotic that can be used to treat bacterial eye infections in newborns and adults.

Penicillin is a beta-lactam antibiotic that can cause allergic reactions in some people.

Cross-sensitivity means that a person who is allergic to one type of antibiotic may also be allergic to another type of antibiotic that has a similar structure or mechanism of action.Erythromycin and penicillin have different structures and mechanisms of action, but there is still a small chance of cross-sensitivity between them.

Therefore, the nurse should check if the newborn has any history of allergic reaction to penicillin before applying the erythromycin eye ointment.

Choice A is wrong because asking the mother if she has any allergies to antibiotics is not enough to determine if the newborn is at risk of an allergic reaction to erythromycin.

The newborn may have inherited or developed an allergy to penicillin or erythromycin that the mother does not have.

Choice C is wrong because applying a small amount of ointment on the skin to test for allergic reaction is not a reliable method to diagnose an allergy.Skin testing can cause false positive or false negative results, and it may also trigger a severe allergic reaction in some cases.

Choice D is wrong because administering an antihistamine to prevent anaphylaxis is not appropriate for a newborn who has not been exposed to the allergen yet.

An antihistamine is a medication that blocks the effects of histamine, a chemical that causes allergic symptoms.

Anaphylaxis is a life-threatening allergic reaction that involves multiple organ systems and requires immediate medical attention.An antihistamine cannot prevent anaphylaxis, and it may also cause side effects such as drowsiness, dry mouth, or low blood pressure in a newborn.

The correct answer is choice A. Glycogen.Preterm newborns have limited stores of glycogen, which is a substance made from glucose that is stored in the liver and muscle cells to be used later for energy.When blood glucose levels are low, the hormone glucagon signals the cells to convert glycogen back into glucose and release it into the bloodstream.However, preterm newborns have a reduced ability to produce glucagon and to use gluconeogenesis, which is the process of making new glucose from other sources.Therefore, they are at risk of hypoglycemia, which is a condition where blood glucose levels are too low to support normal brain function.

Choice B is wrong because glucose is the sugar that travels through the blood to fuel the cells, not a substance that is stored for later use.

Choice C is wrong because insulin is a hormone that helps cells absorb glucose from the blood, not a substance that is stored for later use.

Choice D is wrong because glucagon is a hormone that triggers the release of glucose from the liver and muscle cells, not a substance that is stored for later use.