You are on-scene with an apneic adult who collapsed one to two minutes prior to your arrival, according to bystanders. Which of the following endotracheal tube size ranges would be most appropriate for an average adult respiratory arrest patient who shows no signs of airway trauma or obstruction?

Correct Answer: C

Rationale: The correct answer is C: 7.5-8.5 ET tube. For an adult with no signs of airway trauma or obstruction who is in respiratory arrest, this size range is appropriate. Here's the rationale: 1. Adult size: The range is suitable for an average adult. 2. Apneic adult: The patient is not breathing, requiring intubation for airway management. 3. Timeframe: With a recent collapse, the airway is likely still patent, so a smaller tube is sufficient. 4. No trauma or obstruction: There are no indications for a larger tube. Other choices are incorrect: A: 6.5-8.5 ET tube - This is too broad, and a specific size range is more appropriate. B: 9.0-10.0 ET tube - Larger sizes are not necessary if there are no airway issues. D: 4.5-6.5 ET tube - This size is too small

Correct Answer: A

Rationale: The correct answer is A: Obtain a chest x-ray. When a patient with a closed head injury experiences a decrease in oxygen saturation, it is crucial to rule out potential causes such as a pneumothorax or lung contusion, which can compromise ventilation and oxygenation. A chest x-ray will help identify any underlying pulmonary issues. Decreasing tidal volume (B) or PEEP (C) may not address the specific cause of decreased oxygen saturation in this case. Increasing the rate of assisted ventilations (D) without addressing the underlying issue may not be effective and could potentially worsen the patient's condition.

Correct Answer: C

Rationale: The correct answer is C: Upper airway protection. The highest priority should be given to ensuring the patient's airway is clear and protected, as facial edema and crepitus indicate potential airway compromise. This is crucial to prevent respiratory distress or failure. Assessing the carotid pulse or determining associated injuries can wait until the airway is secured. A lateral c-spine x-ray may be necessary later but is not the immediate priority.

Correct Answer: D

Rationale: Rationale for Correct Answer (D): Widened symphysis pubis is normal in pregnancy due to hormonal changes softening the ligaments, allowing for increased flexibility during childbirth. This physiological adaptation helps in the delivery process. Summary of Incorrect Choices: A: "Increased residual lung volume" is not normal in pregnancy. Respiratory changes include increased tidal volume and minute ventilation, but residual lung volume does not significantly change. B: Decreased plasma volume is not normal in pregnancy. Plasma volume increases to support the growing fetus and maternal circulation. C: Decreased total RBC mass is not normal in pregnancy. Total RBC mass increases to support increased oxygen demands for the mother and fetus.

Correct Answer: A

Rationale: The correct answer is A: "10 min". The brain can be anoxic, or deprived of oxygen, for about 10 minutes before irreversible damage occurs. During oxygen deprivation, brain cells begin to die within minutes, leading to permanent brain damage. Oxygen is essential for brain function and prolonged anoxia can result in cognitive impairment, disability, or even death. Choice B (5 min), C (2 min), and D (20 min) are incorrect because they do not align with the typical timeframe for irreversible brain damage due to oxygen deprivation.