Which of the following is a common cause of cardiac arrest in children?

Respiratory failure or apnea is indeed a common cause of cardiac arrest in children. In pediatric patients, the initial cause of cardiac arrest often stems from respiratory issues rather than cardiac problems, which is more typical in adults. Children have smaller airways, and any obstruction or failure to breathe effectively can quickly lead to hypoxia (insufficient oxygen in the body). If this hypoxia is not corrected, it can result in respiratory failure, followed by decreased perfusion to vital organs. As a result, the heart can then become compromised, leading to arrest.

When assessing pediatric cases, it is crucial to recognize that early recognition and treatment of respiratory distress or failure can help prevent cardiac arrest. Therefore, ensuring adequate ventilation and oxygenation is key in managing emergencies in children, emphasizing the importance of addressing respiratory issues promptly.

The other options, while they can contribute to emergencies, do not primarily lead to cardiac arrest in children as commonly as respiratory failure or apnea. Severe allergic reactions can lead to rapid decline but typically cause respiratory compromise. Hypotension usually occurs as a consequence rather than a primary cause. Bradycardia can result from various issues but is not a direct primary cause of cardiac arrest in pediatric patients.