What is the preferred first-line vasopressor for septic shock?

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

Answer: (B)

In septic shock, widespread vasodilation lowers mean arterial pressure, so the goal is to restore perfusion by increasing vascular tone with a vasopressor. Norepinephrine is the preferred first-line choice because its strong alpha-adrenergic effects raise systemic vascular resistance and MAP with relatively modest impact on heart rate. It also provides some beta-1 activity to support cardiac output without the pronounced tachycardia and arrhythmias seen with other agents.

Dopamine can cause more irregular heart rhythms and hasn’t shown the same outcome benefits as norepinephrine. Epinephrine can elevate heart rate and myocardial oxygen demand and may raise lactate, which can complicate assessment. Phenylephrine is a pure alpha agonist that can raise blood pressure but often decreases cardiac output and organ perfusion, especially in patients with limited cardiac reserve.

Guidelines generally target a MAP of about 65 mmHg, starting with norepinephrine and escalating as needed, sometimes adding other agents if the response is insufficient.