BCEN CEN Prep Online

Aortic dissection involving the arch classically presents with abrupt, severe “tearing” chest pain radiating to the back, and it can produce pulse or blood pressure differentials between arms due to involvement of major branch vessels. Neurologic deficits (such as sudden unilateral weakness) can occur when the dissection compromises cerebral perfusion, which is more consistent with arch involvement. Acute myocardial infarction can cause chest pain but typically does not cause a large inter-arm blood pressure difference or focal neurologic deficits from branch-vessel compromise. Pulmonary embolism may cause pleuritic chest pain and dyspnea but does not usually produce inter-arm blood pressure differences or focal unilateral weakness. Ischemic stroke explains sudden unilateral weakness but does not explain the tearing chest pain radiating to the back with inter-arm blood pressure discrepancy.

A splash of a strong cleaning chemical into the eye requires immediate, copious irrigation because the injury can continue to worsen as long as the chemical remains in contact with ocular tissues. Rapid flushing with water or normal saline (while removing contact lenses and checking ocular pH when available) helps dilute and remove the agent, limiting penetration and preventing permanent corneal damage and vision loss. Thermal injuries from hot water or steam and UV-related photokeratitis can be painful and require evaluation, but they do not typically involve the same ongoing chemical reaction that must be stopped immediately by decontamination.

In acute methamphetamine (sympathomimetic) intoxication with severe agitation, the safest and most effective initial pharmacologic step is sedation with benzodiazepines to reduce agitation and adrenergic excess (e.g., tachycardia, hypertension, hyperthermia risk). This supports de-escalation and helps protect both the patient and staff. The choice that starts with “antipsychotics as first-line therapy” is generally not preferred initially because benzodiazepines are first-line for stimulant intoxication; antipsychotics may be considered as adjuncts in selected cases but are not the initial step. The choice describing “physical restraints immediately” is inappropriate as a first intervention because restraints can worsen agitation and hyperthermia and should be reserved for situations where the patient remains unsafe despite verbal de-escalation and appropriate sedation. The choice that “starts an intravenous fluid infusion as the first intervention” can be helpful for dehydration or rhabdomyolysis risk, but it does not address the immediate priority of controlling severe agitation and sympathetic overactivity.