Correct Answer: D

Rationale: The most common treatment for Hirschsprung disease is the surgical removal of the affected section of the bowel. This procedure entails excising the part of the colon that lacks nerve cells crucial for normal bowel function. Daily enemas (Choice A) can offer temporary relief for constipation but do not address the root cause of the condition, which is the absence of nerve cells. A low-fiber diet (Choice B) is not a primary therapy for Hirschsprung disease and may not effectively manage the disorder. A permanent colostomy (Choice C) is typically considered in severe cases where other interventions have failed and is not the standard management approach for Hirschsprung disease.

Correct Answer: D

Rationale: When caring for a child with acute laryngotracheobronchitis, the priority action should be to continually assess the respiratory status. This is crucial to detect early signs of respiratory distress, such as worsening stridor or increased work of breathing. Prompt intervention can prevent further deterioration of the child's condition. Initiating measures to reduce fever (Choice A) may be necessary but is not the priority in this situation. Ensuring delivery of humidified oxygen (Choice B) is important for maintaining oxygenation but should follow the assessment of respiratory status. Providing support to reduce apprehension (Choice C) is also important for the child's comfort but is not the priority over assessing and managing respiratory distress.

Correct Answer: D

Rationale: The major characteristic of a cardiac malformation associated with left-to-right shunting is increased blood flow to the lungs. This increased flow can lead to pulmonary hypertension and heart failure if left untreated. Elevated hematocrit (Choice A) is not a typical characteristic of this condition. Severe growth retardation (Choice B) is not directly associated with left-to-right shunting. Clubbing of the fingers and toes (Choice C) is more commonly seen in conditions involving chronic hypoxia.

Correct Answer: D

Rationale: The correct answer is D. Mouth breathing due to a cleft lip can dry the mucous membranes, making them more susceptible to infection. Choice A is incorrect because waste products do not accumulate along the defect to predispose the infant to infection. Choice B is incorrect as there is no evidence of inadequate circulation being a primary factor in infection predisposition in cleft lip cases. Choice C is incorrect because although ineffective feeding may lead to other issues, it is not the main reason for infection predisposition in infants with a cleft lip.

Correct Answer: A

Rationale: Infection is the leading cause of shock in infants and children due to their heightened vulnerability to sepsis. Infants and children possess developing immune systems, rendering them more susceptible to infections that can progress to septic shock. While cardiac failure is a severe condition, it is not as commonly the primary cause of shock in this age group. Accidental poisoning, though a potential shock inducer, is less prevalent in infants and children compared to infections. Severe allergic reactions, though significant, are not as frequent as infections in precipitating shock in infants and children.