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 index (SVRI) range for patients on vasopressors is typically 1700-2400 dyne·sec·cm⁻⁵·m², as indicated by a resistive index (RI) of 0.97 and 1.1, respectively, which corresponds to the lower and upper limits of normal SVRI 1. When managing patients on vasopressors such as norepinephrine, phenylephrine, vasopressin, or epinephrine, clinicians should titrate to achieve this SVRI target while maintaining adequate mean arterial pressure (typically 65-75 mmHg). Some key points to consider when using vasopressors include:
- Monitoring for signs of excessive vasoconstriction, including decreased peripheral perfusion, worsening acidosis, or rising lactate levels
- Individualizing the SVRI target based on the patient's underlying condition, with lower targets potentially appropriate for septic shock and higher targets for cardiogenic shock
- Regular reassessment of hemodynamic parameters, as vasopressor requirements typically change throughout the course of critical illness
- Considering the use of non-invasive methods, such as Doppler-derived resistive index, to evaluate peripheral vascular resistance in septic patients, as it is highly correlated with SVRI 1
- Being aware of the potential benefits and limitations of different vasopressor agents, as suggested by studies such as the systematic review and meta-analysis of norepinephrine in septic shock 2 and the network meta-analysis of vasopressors in septic shock 3.