From the Guidelines
Norepinephrine is the first-line vasopressor for treating hypotension in shock. It is typically administered as a continuous intravenous infusion, starting at 0.01-0.03 mcg/kg/min and titrated up to 0.5-1 mcg/kg/min as needed to achieve a target mean arterial pressure (MAP) of at least 65 mmHg 1. Norepinephrine should be administered through a central venous catheter whenever possible, though peripheral administration can be used temporarily while central access is being established. Norepinephrine is preferred because it provides potent vasoconstriction through alpha-1 adrenergic effects while also offering modest beta-1 adrenergic activity that supports cardiac output. This balanced profile helps restore adequate tissue perfusion without the excessive tachycardia or decreased splanchnic perfusion seen with other vasopressors. In septic shock specifically, norepinephrine helps counteract pathologic vasodilation while maintaining cardiac function. If hypotension persists despite escalating doses of norepinephrine, second-line agents such as vasopressin, epinephrine, or phenylephrine may be added based on the specific clinical scenario and underlying cause of shock.
Some key points to consider when using norepinephrine include:
- Starting dose: 0.01-0.03 mcg/kg/min
- Target MAP: at least 65 mmHg
- Administration route: central venous catheter preferred, peripheral administration temporary
- Titration: up to 0.5-1 mcg/kg/min as needed
- Monitoring: close monitoring of blood pressure, cardiac output, and tissue perfusion
It's also important to note that norepinephrine is recommended as the first-line vasopressor by multiple guidelines, including the Surviving Sepsis Campaign 1 and the World Journal of Emergency Surgery 1. Additionally, a global perspective on vasoactive agents in shock also supports the use of norepinephrine as the first-line therapy 1.
From the FDA Drug Label
Vasopressin injection is indicated to increase blood pressure in adults with vasodilatory shock who remain hypotensive despite fluids and catecholamines.
Post-cardiotomy shock: 0.03 to 0.1 units/minute Septic shock: 0.01 to 0. 07 units/minute
The first-line vasopressor for treating hypotension in shock is not explicitly stated in the provided drug labels. However, vasopressin is indicated for increasing blood pressure in adults with vasodilatory shock who remain hypotensive despite fluids and catecholamines 2, 2.
- Key points:
- Vasopressin is used for vasodilatory shock.
- The dosage varies depending on the type of shock (post-cardiotomy or septic). It is essential to consult the full prescribing information and consider the specific clinical context to determine the appropriate vasopressor and dosage for a patient in shock.
From the Research
First-Line Vasopressor for Treating Hypotension in Shock
- The first-line vasopressor for treating hypotension in shock is norepinephrine, as recommended by current international guidelines 3, 4, 5.
- Norepinephrine is considered the cornerstone of hemodynamic management in patients with septic shock 3.
- Compared to dopamine, norepinephrine is associated with decreased all-cause mortality, lower risk for major adverse events, and cardiac arrhythmias 5.
Alternative Vasopressors
- Vasopressin can be considered as a first-line vasopressor in septic shock patients with other risk factors that may contribute to renal failure requiring renal replacement therapy 6.
- Epinephrine is currently considered as a second-line vasopressor therapy due to its higher rate of associated metabolic and cardiac adverse effects compared with norepinephrine 3.
- Angiotensin II appears to be a promising vasopressor in patients with septic shock, especially in the most severe cases and/or in patients with acute kidney injury requiring renal replacement therapy, but its use is not currently recommended due to limited evidence and concerns regarding safety 3, 7.
Clinical Application
- The use of different adjunctive agents in combination with norepinephrine may be useful in patients with refractory septic shock, but care must be taken to avoid excessive vasoconstriction 7.
- Norepinephrine equivalence (NEE) is frequently used in clinical trials to overcome heterogeneity and describe vasopressor support in a standardized manner, but it has several pitfalls, including a lack of conversion of novel vasopressors and adjuncts 4.