From the FDA Drug Label
In patients with vasodilatory shock vasopressin in therapeutic doses increases systemic vascular resistance and mean arterial blood pressure and reduces the dose requirements for norepinephrine.
The FDA drug label does not answer the question.
From the Research
The recommended systemic vascular resistance (SVR) range when using vasopressors is typically 800-1200 dynes·sec/cm⁵. When managing patients on vasopressors such as norepinephrine, phenylephrine, vasopressin, or epinephrine, clinicians should target this range to maintain adequate tissue perfusion while avoiding excessive vasoconstriction, as supported by a recent study 1. Starting doses vary by medication: norepinephrine typically begins at 0.01-0.05 mcg/kg/min, phenylephrine at 0.1-0.5 mcg/kg/min, vasopressin at 0.01-0.04 units/min, and epinephrine at 0.01-0.05 mcg/kg/min. Titration should be based on both SVR values and mean arterial pressure (MAP), generally targeting a MAP of 65-75 mmHg.
Some key points to consider when managing SVR in patients on vasopressors include:
- Regular assessment of end-organ perfusion is essential, including monitoring urine output, lactate levels, and mental status.
- SVR values below 800 dynes·sec/cm⁵ may indicate vasodilatory shock requiring increased vasopressor support, while values above 1200 dynes·sec/cm⁵ can lead to excessive afterload, reduced cardiac output, and tissue hypoperfusion despite adequate blood pressure readings, as noted in a study on cardiogenic shock 1.
- The goal is to use the minimum effective dose to maintain adequate perfusion while minimizing potential adverse effects of vasopressors.
- Other studies have explored the use of vasopressin in specific contexts, such as after cardiopulmonary bypass 2 or in comparison with norepinephrine 3, but the key principle of targeting an SVR range of 800-1200 dynes·sec/cm⁵ remains consistent.
Overall, the management of SVR in patients on vasopressors requires careful consideration of the individual patient's hemodynamic status and close monitoring to avoid complications, as highlighted by research on low systemic vascular resistance states 4. Targeting an SVR range of 800-1200 dynes·sec/cm⁵ is crucial for optimizing outcomes in these patients.