A patient has experienced a myocardial infarction. On which primary blood vessel will the nurse focus care to reduce ischemia?

Correct Answer: C

Rationale: Myocardial infarction results from reduced coronary artery blood flow, causing ischemia. The nurse focuses on the coronary artery to restore oxygenation to the heart muscle, not the vena cava, pulmonary artery, or carotid artery.

Correct Answer: B

Rationale: Accessory muscle use (e.g., neck, shoulders) suggests respiratory distress, as the patient struggles to breathe, not normal breathing, improved oxygenation, or mere fatigue.

Correct Answer: A

Rationale: Anemia reduces hemoglobin, the oxygen-carrying component of blood, directly impairing oxygenation, unlike blood pressure, airway issues, or fluid overload.

Correct Answer: A

Rationale: Carbon monoxide poisoning causes cherry-red lips due to carboxyhemoglobin formation, impairing oxygen delivery. This is a specific, priority sign over fever, tachycardia, or hypotension.

Correct Answer: A

Rationale: Respiratory infections can cause mucus plugging and airway obstruction, leading to atelectasis (lung collapse), more than hypertension, bradycardia, or hyperglycemia.