Which agent is specifically mixed into a 250 ml bag of IV fluid for hypotension management?

• A. Phenylephrine
• B. Ephedrine
• C. Epinephrine
• D. Norepinephrine

Answer: (A)

The main idea is using a titratable vasopressor infusion to treat hypotension, commonly prepared by diluting the drug in an IV fluid bag for controlled administration. Phenylephrine is a pure alpha-1 agonist, so it causes vasoconstriction that raises systemic vascular resistance and blood pressure with minimal effect on heart rate. This makes it ideal for managing neuraxial anesthesia–related hypotension, where you want to steadily maintain blood pressure without stimulating the heart. Clinicians often mix phenylephrine into a 250 mL bag of saline to create a ready-to-titrate infusion.

Ephedrine has both alpha and beta effects and is more likely to increase heart rate, which can be undesirable in this setting. Epinephrine and norepinephrine are powerful vasopressors with broader cardiac effects and are less commonly used as routine bag infusions for hypotension in this context.