A client presents to the emergency department reporting chest pain. Which order should the nurse complete first?

Choice A rationale Troponin is a specific biomarker released during myocardial cell necrosis, typically peaking between 12 to 24 hours after injury. The normal range for Troponin T is less than 0.01 ng/mL. While essential for diagnosing an infarction, it is a laboratory value that requires time for processing. It does not provide the immediate diagnostic visualization needed to distinguish between ST-elevation myocardial infarction and non-ischemic causes of chest pain in the first minutes of care. Choice B rationale Aspirin acts as an antiplatelet agent by irreversibly inhibiting cyclooxygenase-1, which prevents the synthesis of thromboxane A2. This action inhibits platelet aggregation and reduces the risk of further thrombus formation in the coronary arteries. While administration is a high priority in the acute coronary syndrome protocol, the nurse must first establish the underlying cardiac rhythm and electrical status via an electrocardiogram to guide the overall speed and type of medical intervention required. Choice C rationale Monitoring intake and output is a standard nursing intervention used to evaluate fluid balance and renal perfusion, which can be compromised in heart failure or cardiogenic shock. However, in the hyperacute phase of chest pain, this task is not a life-saving or diagnostic priority. Measuring urine output or fluid intake does not address the immediate need to identify coronary ischemia or prevent further myocardial damage during the initial emergency department assessment. Choice D rationale A 12-lead ECG is the gold standard for immediate assessment of chest pain because it identifies myocardial ischemia or injury within seconds. It allows the clinical team to recognize ST-segment elevation, which necessitates rapid reperfusion therapy like fibrinolysis or percutaneous coronary intervention. According to standard emergency protocols, an ECG should be performed and interpreted within 10 minutes of arrival to minimize the door-to-balloon time and preserve viable myocardial tissue from irreversible necrosis.