Correct Answer: C

Rationale: When assisting ventilations in a 4-year-old child with a bag-valve mask, the EMT should block the pop-off valve if needed to achieve adequate chest rise. This action helps ensure effective ventilation and adequate oxygenation in the child. Blocking the pop-off valve allows for better control over the volume of air delivered and can help maintain positive pressure in the airway, assisting in improving oxygenation and ventilation in the child. Choices A, B, and D are incorrect because delivering each breath over 2 to 3 seconds is a general guideline but may need adjustment based on patient response, ensuring the appropriate mask size is important but not the primary concern in this scenario, and reassessing the pulse rate is not directly related to the ventilation technique being discussed.

Correct Answer: C

Rationale: During resuscitation of an apneic infant, the appropriate ventilation rate is 12 to 20 breaths per minute. This rate helps provide adequate oxygenation and ventilation without causing harm to the infant. Choice A (8 to 10 breaths/min) is too low and may not provide sufficient ventilation. Choice B (10 to 12 breaths/min) is slightly below the recommended range, which may not be optimal for effective resuscitation. Choice D (20 to 30 breaths/min) is too high and may lead to overventilation and potential harm to the infant by causing hypocapnia.

Correct Answer: D

Rationale: Allowing the chest to fully recoil between compressions is crucial during CPR to ensure proper blood flow. This action allows the heart to refill with blood, enhancing the effectiveness of compressions and circulation. Hyperventilating the patient can lead to decreased cardiac output and is not recommended. Attaching AED pads should be done as soon as possible in a pediatric cardiac arrest situation, ideally within 2 minutes. The correct compression-to-ventilation ratio for pediatric CPR is 30:2, focusing on high-quality compressions to provide adequate perfusion to vital organs.

Correct Answer: A

Rationale: When ventilating an apneic child, the most important action is to avoid hyperventilation and ensure adequate chest rise. Hyperventilation can lead to decreased cardiac output and increased intracranial pressure. Adequate chest rise confirms effective ventilation and minimizes the risk of complications. Choice B is incorrect because using both hands to squeeze the bag may not ensure proper ventilation and can lead to complications. Choice C is incorrect as inserting an oropharyngeal airway is not the initial action in ventilating an apneic child with a bag-valve mask. Choice D is incorrect as providing ventilations every 3 to 5 seconds may not be appropriate for effective ventilation in a pediatric patient.

Correct Answer: C

Rationale: In a breech presentation, where the baby's buttocks or feet present first, there is an increased risk of the umbilical cord slipping down alongside or below the presenting part, leading to a prolapsed umbilical cord. This is a serious complication that can compromise fetal blood flow and oxygenation, necessitating prompt intervention to prevent adverse outcomes. Choices A, B, and D are less likely to occur in conjunction with a breech presentation. Vertex presentation is the normal head-first presentation, maternal hypertension is a separate condition that may not be directly related to fetal presentation, and premature rupture of the amniotic sac can happen independently of the baby's presentation.