Correct Answer: A

Rationale: The most effective way to prevent cardiopulmonary arrest in a newborn is to ensure effective oxygenation and ventilation. This is crucial in maintaining adequate oxygen supply and preventing respiratory distress or failure, which are significant factors leading to cardiopulmonary arrest. Providing appropriate ventilation support and oxygenation can help sustain the newborn's vital functions and reduce the risk of cardiopulmonary compromise.

Correct Answer: D

Rationale: For a responsive 4-year-old child with a mild airway obstruction, respiratory distress, a strong cough, and normal skin color, the appropriate treatment includes providing supplemental oxygen and arranging for transport to a healthcare facility. Oxygen helps alleviate the respiratory distress, and transport ensures the child receives further evaluation and care by healthcare professionals. Back slaps and subdiaphragmatic thrusts are not recommended for a child with a mild airway obstruction and normal skin color, as these interventions are typically reserved for more severe cases of airway obstruction.

Correct Answer: C

Rationale: In a pediatric patient with respiratory distress, a non-rebreathing mask with a flow rate set at 6 to 8 L/min is the most effective way to deliver oxygen. This method ensures a high concentration of oxygen is delivered to the child, aiding in improving oxygen saturation levels. In this scenario, the mother can assist in holding the mask to maintain comfort and cooperation in the child while ensuring proper oxygen delivery.

Correct Answer: D

Rationale: In this scenario, the 4-year-old boy with a tracheostomy tube is showing signs of respiratory distress, including intercostal retractions, a low heart rate, and decreased oxygen saturation. The gurgling sound indicates a possible airway obstruction. Correctly, the immediate action should be to carefully suction the tracheostomy tube. Suctioning can help clear any secretions or obstructions, thus improving the child's ability to breathe effectively. Ventilating through the tube, placing an oxygen mask over it, or removing and cleaning the tube would not address the potential obstruction and could worsen the respiratory distress.

Correct Answer: B

Rationale: In a 3-year-old child with a sudden onset of respiratory distress and no recent illnesses or fever, the likely cause is a foreign body airway obstruction. Foreign body obstruction can lead to sudden respiratory distress without other preceding symptoms. It is crucial to consider this possibility and act promptly to clear the airway in such cases to prevent serious complications.