An infant is experiencing dyspnea related to patent ductus arteriosus (PDA). The nurse understands dyspnea occurs because blood

A. Shunted past the pulmonary circulation, causing pulmonary hypoxia: This option is not the primary reason for dyspnea in PDA. While there is shunting, it doesn't directly cause pulmonary hypoxia.

B. Circulated through the lungs again, causing pulmonary circulatory congestion: This option is partially correct but does not address the primary reason for dyspnea, which is the bypassing of the left side of the heart.

C. Circulated through the ductus from the pulmonary artery to the aorta, bypassing the left side of the heart.

In patent ductus arteriosus (PDA), a fetal blood vessel called the ductus arteriosus fails to close after birth. This allows oxygenated blood from the left atrium to be shunted directly from the aorta to the pulmonary artery, bypassing the normal route through the left side of the heart and into the systemic circulation. The shunting of oxygenated blood back into the pulmonary circulation can lead to increased pulmonary blood flow and circulatory congestion, causing symptoms such as dyspnea.

D. Shunted past cardiac arteries, causing myocardial hypoxia: PDA primarily affects the pulmonary circulation and left side of the heart, not the coronary arteries. Myocardial hypoxia is not the primary mechanism of dyspnea in PDA.

A. A fontanelle that bulges with crying.

Myelomeningocele is a congenital neural tube defect that involves the spinal cord. It is associated with an increased risk of hydrocephalus, which can lead to increased intracranial pressure (ICP). The fontanelle (soft spot) on an infant's head can provide insight into ICP. When an infant with myelomeningocele has an increase in intracranial pressure, the fontanelle may bulge, especially when the infant cries. This is due to the buildup of cerebrospinal fluid within the skull.

B. Increased respiratory rate: While increased intracranial pressure can affect various body systems, an increased respiratory rate is not a specific sign of ICP associated with myelomeningocele.

C. A high-pitched cry: A high-pitched cry is not typically associated with increased intracranial pressure in the context of myelomeningocele. Signs of ICP in infants may include irritability, lethargy, vomiting, and changes in head circumference.

D. Tachycardia: Tachycardia can be a response to stress or discomfort in an infant, but it is not a specific indicator of increased intracranial pressure related to myelomeningocele.