The nurse initiates a vasopressin drip for the client with gastrointestinal bleeding. What should the nurse consider the priority assessment?

Rationale: A. ST-segment changes on an ECG indicate myocardial ischemia. While ischemia can occur if vasopressin increases cardiac workload, focusing only on ST changes is too narrow. Continuous monitoring for all types of cardiac dysrhythmias is more comprehensive and critical when using vasopressin. B. Vasopressin is a potent vasoconstrictor used to control gastrointestinal bleeding, such as bleeding esophageal varices. Its mechanism of action increases systemic vascular resistance and can raise afterload, thereby increasing myocardial oxygen demand. In clients with underlying cardiac disease (common in adults with GI bleeding), this can precipitate dysrhythmias such as ventricular tachycardia, bradycardia, or heart block. Continuous ECG monitoring allows for early detection and immediate intervention if life-threatening arrhythmias occur. This makes cardiac dysrhythmia assessment the priority safety concern while administering vasopressin. C. Vasopressin does not directly cause bowel obstruction. While general gastrointestinal assessment remains part of comprehensive care, it is not specifically linked to vasopressin therapy or an urgent safety concern. D. Vasopressin generally increases blood pressure due to vasoconstriction. Hypotension is not an expected effect; in fact, monitoring for hypertension or excessive vasoconstriction might be more relevant. Although blood pressure monitoring is important, it is secondary to cardiac monitoring because dysrhythmias can develop even when blood pressure is stable.