The nurse is assessing a child with a cardiac problem. The child's extremities are cool with thready pulses, and urinary output is diminished. This is most suggestive of which of the following?

Hypercyanotic spells, also known as "Tet spells," can occur in infants with congenital heart defects, particularly tetralogy of Fallot. During these spells, there is a sudden decrease in oxygen saturation, leading to cyanosis (blueness) of the infant's skin and lips, as well as respiratory distress and possible loss of consciousness.
The knee-chest position is a specific technique used to manage hypercyanotic spells. Placing the child in this position helps improve oxygenation by increasing systemic vascular resistance and reducing the degree of right-to-left shunting of blood in the heart. It also increases venous return to the heart, which can help improve cardiac output.

Now, let's discuss why the other options are incorrect:
A. Prepare family for imminent death: This is not the priority action. While hypercyanotic spells can be life-threatening, the immediate focus should be on managing the spell to improve oxygenation and prevent further deterioration. Preparing the family for death should only be considered if resuscitation measures fail, which is not the first-line intervention.
C. Assess for neurologic defects: Assessing for neurologic defects is important but not the immediate priority during a hypercyanotic spell. The primary concern at this moment is addressing cyanosis and respiratory distress to ensure the infant receives adequate oxygen.
D. Begin cardiopulmonary resuscitation: Initiating CPR is not the initial priority during a hypercyanotic spell. CPR would be indicated if the infant's condition deteriorates to the point of cardiac arrest, but it should not be the first step. Placing the child in the knee-chest position is a non-invasive intervention that should be attempted before considering CPR.

When obtaining the history of a child with suspected rheumatic fever, the nurse should consider the following information to be most significant:

B. A recent episode of pharyngitis.

Explanation:

Rheumatic fever often follows an untreated or inadequately treated streptococcal pharyngitis (strep throat) infection caused by Group A Streptococcus bacteria. Therefore, a recent episode of pharyngitis is a key piece of information in the context of rheumatic fever. It is important to assess whether the child had a sore throat, fever, and other symptoms of streptococcal infection that may have triggered the development of rheumatic fever.

While the other symptoms (vomiting, lack of interest in food, fever) may be important for the overall assessment and management of the child, they are not as directly associated with the development of rheumatic fever as a recent episode of pharyngitis caused by Group A Streptococcus. Rheumatic fever is an autoimmune response to untreated streptococcal infection, and its diagnosis is often linked to the presence of preceding streptococcal pharyngitis.