Multiple Choice
A 28-year-old man is the unrestrained driver in a motor vehicle collision. He is conscious immediately after the collision and refuses transfer to a hospital for detailed evaluation. Two hours later, he is brought to the emergency department due to progressively worsening mental status. Systolic blood pressure is 60 mm Hg, pulse is 130/min, and respirations are 30/min. On examination, the patient is stuporous and responsive only to noxious stimuli. There are bruises over the extremities and upper abdomen. The trachea is midline, neck veins are flat, and abdomen is distended but nontender. Large-bore peripheral intravenous lines are secured to begin fluid resuscitation while the trachea is intubated. Immediately after the patient is placed on mechanical ventilation, the cardiac monitor shows asystole and no pulse is palpable. Which of the following is the most likely underlying mechanism leading to cardiac arrest in this patient?
A) Decreased right ventricular preload
B) Decreased systemic vascular resistance
C) Increased parasympathetic activity
D) Increased pulmonary vascular resistance
E) Reduced myocardial contractility
Correct Answer:

Verified
Correct Answer:
Verified
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