In an anesthetic emergency, which drug is most appropriate for increasing heart rate and cardiac output?

• A. Dopamine
• B. Vasopressin
• C. Norepinephrine
• D. Adrenaline (Epinephrine)

Answer: (D)

The main idea is that in an anesthetic emergency you want a drug that directly boosts heart activity and how hard the heart pumps. Epinephrine does this best because it strongly stimulates beta-1 receptors in the heart, which increases both heart rate and the force of contraction, so the cardiac output rises quickly. It also helps maintain blood pressure through its alpha effects at higher doses, supporting perfusion to vital organs.

Dopamine can raise heart rate and output, but its effects are dose-dependent and less predictable, and it can cause unwanted tachyarrhythmias. Norepinephrine mainly increases vascular tone with a strong alpha effect and only modest beta-1 support, which can raise afterload and sometimes reduce output. Vasopressin tightens vessels without increasing heart rate or contractility. So epinephrine provides the most reliable combination of increased heart rate and cardiac output in this setting.