You are on-scene with a patient who you suspect may be experiencing a myocardial infarction. He is conscious and alert, anxious, and has dilated pupils. He complains of substernal chest pain and admits to recent cocaine use. How does the use of cocaine increase the risk of experiencing an acute myocardial infarction?

Correct Answer: D

Rationale: The correct answer is D. Cocaine causes constriction of coronary arteries, leading to decreased blood flow to the heart muscle. This constriction can increase the chance of dislodging a thrombus or plaque, ultimately causing an acute myocardial infarction. Choice A is incorrect as speeding the heart rate to the point of asystole is unlikely with cocaine use. Choice B is incorrect as cocaine-induced clotting in the periphery does not directly lead to clots traveling to the coronary arteries. Choice C is incorrect as cocaine does not numb the heart but rather affects coronary perfusion negatively.

Correct Answer: C

Rationale: The correct answer is C: Administer defibrillation per protocol. The patient is presenting with symptoms indicative of unstable ventricular tachycardia or ventricular fibrillation, which are life-threatening arrhythmias. Defibrillation is the immediate intervention to restore normal rhythm by delivering an electrical shock to the heart. In this scenario, the patient is hemodynamically unstable with a low blood pressure and loss of consciousness, making defibrillation the most appropriate and effective intervention to potentially save the patient's life. Choice A (Administer procainamide) is not the most effective intervention as this patient is in a critical condition that requires immediate action, and procainamide infusion takes time to work. Choice B (Administer adenosine) is typically used for supraventricular tachycardias and is not appropriate for wide complex tachycardias. Choice D (Administer synchronized electrical cardioversion) is indicated for stable wide complex tachycardias

Correct Answer: A

Rationale: The correct answer is A: "Inserting an oropharyngeal airway." In this scenario of a motorcycle crash with noisy respirations, apnea, and a hematoma in the pharynx, the patient is likely experiencing airway obstruction. An oropharyngeal airway helps maintain a patent airway by preventing the collapse of the tongue and soft tissues in the oropharynx. It does not require visualization or manipulation of the upper airway structures, making it the most suitable initial intervention in this emergent situation. Summary of why the other choices are incorrect: B: "Inserting a nasopharyngeal airway" - Nasopharyngeal airways are not recommended in the presence of facial trauma or suspected basilar skull fracture due to the risk of exacerbating the injury. C: "Performing a surgical cricothyroidotomy" - This is an invasive procedure reserved for extreme cases of airway obstruction when other methods fail. D

Correct Answer: D

Rationale: The correct answer is D because an endotracheal tube (ETT) above the carina on a chest x-ray is the most reliable indicator of esophageal intubation. This is because direct visualization of the ETT position relative to the carina is definitive evidence of correct placement. A, B, and C are less reliable signs as they can be misleading in certain circumstances. Symmetrical chest movement can occur even with esophageal intubation due to passive chest rise. End-tidal CO2 presence by colorimetry can be falsely positive in cases of esophageal intubation. Bilateral breath sounds can also be heard in the abdomen with esophageal intubation, leading to a false sense of correct placement.

Correct Answer: B

Rationale: The correct answer is B - Undergo prompt celiotomy. In this scenario, the presence of diffuse abdominal tenderness and free air on abdominal films indicates a high likelihood of intraabdominal injury, likely due to a gastrointestinal perforation. Prompt celiotomy (surgical exploration of the abdomen) is necessary to identify and repair the source of the perforation to prevent sepsis and other complications. Peritoneal lavage (choice A) is not sufficient for definitive diagnosis and treatment. Contrast x-ray (choice C) delays necessary surgical intervention. Simply observing (choice D) can be dangerous as the patient may deteriorate rapidly. Celiotomy allows for immediate intervention and management of the life-threatening condition.