In septic shock, what is the hemodynamic effect when norepinephrine is titrated?

• A. Decreases systemic vascular resistance and MAP
• B. Increases systemic vascular resistance and MAP; may decrease venous return at high doses
• C. Significantly increases venous return
• D. No effect on vascular tone

Answer: (B)

In septic shock, norepinephrine works primarily to restore blood pressure by tightening arterial vessels. Its alpha-adrenergic effects raise systemic vascular resistance, which increases mean arterial pressure. It also has some beta-1 effects that can help support cardiac performance, aiding overall perfusion as the dose is adjusted. As you increase the dose, the strong vasoconstriction can also constrict the venous reservoir; at high doses this can reduce venous return to the heart, potentially lowering preload and, paradoxically, limiting forward flow. So the overall expected hemodynamic effect with titration is an increase in systemic vascular resistance and MAP, with venous return possibly decreasing at higher doses.