From the Guidelines
Pressors should typically be started after 2-3 fluid boluses (usually 30 mL/kg total) if the patient remains hypotensive despite adequate fluid resuscitation. This approach is supported by the Surviving Sepsis Campaign guidelines, which recommend initial resuscitation with at least 30 mL/kg of IV crystalloid fluid within the first 3 hours 1. The guidelines also suggest guiding resuscitation to normalize lactate in patients with elevated lactate levels as a marker of tissue hypoperfusion 1.
Key Considerations
- The initial fluid resuscitation should be followed by frequent reassessment of hemodynamic status to determine the need for additional fluids or vasopressors 1.
- Norepinephrine is the first-line vasopressor for septic shock, with a recommended starting dose of 0.05-0.1 mcg/kg/min, titrated to effect 2.
- The target mean arterial pressure (MAP) should be 65 mmHg for most patients 2, 1.
- Ongoing assessment of fluid status remains important even after starting pressors, as some patients may require additional fluid resuscitation.
Vasopressor Selection
- Norepinephrine is the recommended first-choice vasopressor, with epinephrine or vasopressin added as needed to maintain adequate blood pressure 2.
- Dopamine may be used as an alternative vasopressor agent in highly selected patients, such as those with low risk of tachyarrhythmias and absolute or relative bradycardia 2.
- Phenylephrine is not recommended as a first-line vasopressor, but may be used in specific circumstances, such as when norepinephrine is associated with serious arrhythmias or as salvage therapy 2.
From the Research
Fluid Boluses and Pressors
- The optimal number of fluid boluses before starting pressors is not explicitly stated in the provided studies 3, 4, 5, 6, 7.
- However, a study published in JAMA in 2023 4 mentions that among patients with sepsis who received 1 to 2 L of fluid, goal-directed therapy administering fluid boluses to attain a central venous pressure of 8 to 12 mm Hg, vasopressors to attain a mean arterial blood pressure of 65 to 90 mm Hg, and red blood cell transfusions or inotropes to attain a central venous oxygen saturation of at least 70% did not decrease mortality compared with unstructured clinical care.
- Another study published in the same journal 4 reported that among patients with sepsis and hypotension who received 1 L of fluid, favoring vasopressor treatment did not improve mortality compared with further fluid administration.
- A systematic review and meta-analysis published in PloS one in 2015 3 recommends dopamine or norepinephrine as first-line vasopressor agents in septic shock, but does not provide guidance on the number of fluid boluses before starting pressors.
- The decision to start pressors should be based on individual patient factors, such as the severity of sepsis, hemodynamic parameters, and response to fluid therapy, rather than a fixed number of fluid boluses 5, 6.