You are treating a 50-year-old male with a cardiac history currently complaining of chest pain. He is breathing at 20 times a minute, has an irregular heart rate of 136 beats per minute, and a blood pressure of 120/60. His twelve-lead-tracing indicates the presence of an ST-elevation myocardial infarction (STEMI). What makes the ST-elevation infarction treatment different from a non-STEMI patient's treatment?

Correct Answer: B

Rationale: The correct answer is B because in ST-elevation myocardial infarction (STEMI), immediate reperfusion therapy is crucial to restore blood flow to the affected area and prevent irreversible damage to the heart muscle. Fibrinolytics can be used to achieve this goal, but the time from symptom onset to treatment initiation is critical. Time is muscle in STEMI, so early recognition, prompt activation of the cath lab, and rapid transfer to a PCI-capable hospital are essential. In contrast, non-ST elevation infarctions may not require immediate reperfusion therapy and may respond to medical management initially. Choice A is incorrect because the urgency of treatment is not as time-sensitive in non-STEMI. Choice C is incorrect because fluid bolus is not a standard treatment for STEMI, and choice D is incorrect because the management differs between STEMI and non-STEMI.

Correct Answer: C

Rationale: Rationale: In the absence of amiodarone, lidocaine is the preferred alternative for ventricular fibrillation. Lidocaine is a Class Ib antiarrhythmic agent that can be used to stabilize cardiac rhythms in cardiac arrest situations. It works by blocking sodium channels in the heart, helping to restore a normal heart rhythm. Epinephrine (A) is primarily used for its effects on increasing heart rate and blood pressure during cardiac arrest. Cardizem (B) is a calcium channel blocker and not typically used for ventricular fibrillation. Procainamide (D) is a Class Ia antiarrhythmic drug that is less commonly used for ventricular arrhythmias and is not the preferred alternative in this scenario.

Correct Answer: A

Rationale: Correct Answer: A - Transcutaneous pacing (TCP) Rationale: 1. Atropine blocks parasympathetic response, so lack of heart rate increase indicates a severe bradycardia. 2. TCP provides immediate pacing to increase heart rate and cardiac output. 3. It is the most appropriate action when medications like atropine fail. 4. Synchronized cardioversion (choice B) is used for unstable tachyarrhythmias, not bradycardia. 5. Repeating atropine (choice C) may not be effective if the initial dose failed. 6. Epinephrine (choice D) is used in cardiac arrest, not as the first-line treatment for symptomatic bradycardia.

Correct Answer: D

Rationale: The correct answer is D: Perform endotracheal intubation and ventilation. This step is crucial in ensuring adequate oxygenation and ventilation in a trauma patient with potential airway compromise. By securing the airway and providing ventilation, we can prevent hypoxia and further injury. Obtaining a lateral cervical spine x-ray (A) is important in evaluating for potential spinal cord injury but should not delay airway management. Inserting a central venous pressure line (B) is not a priority in the initial management of a trauma patient. Administering crystalloid solution (C) may be necessary later, but airway management takes precedence in this critical situation.

Correct Answer: C

Rationale: The Rule of Nines is used to estimate the percentage of body surface area burned. In infants, the head is proportionally larger compared to adults, making it a key area to assess accurately. This is crucial for determining the extent of burns and guiding treatment. Choice C is correct because it highlights the specific anatomical difference in infants. Choices A, B, and D are incorrect as they do not address the unique proportionality of the infant head compared to adults, which is essential in burn assessment for this age group.