The nurse is conducting an admission assessment of an infant with heart failure who is scheduled for repair of restenosis of coarctation of the aorta that was repaired 4 days after birth. Findings include blood pressure higher in the arms than the lower extremities, pounding brachial pulses, and slightly palpable femoral pulses. Which pathophysiologic mechanism supports these findings?

Choice A reason: Encouraging the parent to come to the clinic if the child develops a fever is not the best response that the nurse can give. This is because a fever may indicate a serious infection, such as Lyme disease, that requires prompt treatment. The nurse should not wait for the child to develop a fever before advising the parent to seek medical attention.

Choice B reason: Instructing the parent to apply an antihistamine ointment for one week is not the best response that the nurse can give. This is because an antihistamine ointment may not be effective for a fungal infection, such as ringworm, or a bacterial infection, such as Lyme disease, that may cause a circular rash. The nurse should not recommend any OTC product without knowing the exact cause of the rash.

Choice C reason: Offering reassurance that OTC corticosteroid creams are safe and effective is not the best response that the nurse can give. This is because corticosteroid creams may worsen a fungal infection, such as ringworm, or mask the symptoms of a bacterial infection, such as Lyme disease, that may cause a circular rash. The nurse should not recommend any OTC product without knowing the exact cause of the rash.

Choice D reason: Explaining the need for the child to have an immediate medical evaluation is the best response that the nurse can give. This is because a circular rash can be a sign of a serious condition, such as Lyme disease, that requires urgent diagnosis and treatment. The nurse should inform the parent that the rash may not be ringworm, as many people assume, and that it may be caused by a tick bite or another factor. The nurse should also advise the parent to avoid touching or scratching the rash and to keep it clean and dry until the child sees a doctor.

Choice A reason: Chest pain is a sign of acute chest syndrome, which is a life-threatening complication of sickle cell crisis. It occurs when the sickle-shaped red blood cells block the blood vessels in the lungs, causing inflammation, infection, and low oxygen levels. Chest pain may be accompanied by fever, cough, shortness of breath, and wheezes. The nurse should report chest pain to the health care provider immediately and monitor the child's vital signs, oxygen saturation, and respiratory status.

Choice B reason: Jaundice is a common finding in children with sickle cell disease, but it is not an urgent sign of sickle cell crisis. Jaundice occurs when the red blood cells break down faster than the liver can process them, resulting in a buildup of bilirubin in the blood and skin. Jaundice may cause yellowing of the skin, eyes, and mucous membranes, as well as itching and dark urine. The nurse should assess the child's liver function and hydration status, but jaundice does not require immediate intervention.

Choice C reason: Ulcers on the legs are a chronic complication of sickle cell disease, but they are not an acute sign of sickle cell crisis. Ulcers on the legs occur when the blood flow to the skin is impaired by the sickle-shaped red blood cells, causing tissue damage and infection. Ulcers on the legs may cause pain, swelling, and drainage, and they may take a long time to heal. The nurse should clean and dress the ulcers, apply topical antibiotics, and elevate the legs, but ulcers do not require immediate intervention.

Choice D reason: Swelling in the hands or feet is a common finding in children with sickle cell disease, especially in infants and toddlers, but it is not a critical sign of sickle cell crisis. Swelling in the hands or feet occurs when the sickle-shaped red blood cells block the blood vessels in the extremities, causing inflammation and fluid retention. Swelling in the hands or feet may cause pain, stiffness, and difficulty moving the joints. The nurse should apply warm compresses, massage the affected areas, and encourage the child to exercise the joints, but swelling does not require immediate intervention.