Choosing the Right Vasopressor Agent in Hypotension

Table of Vasopressor Effects, Side Effects, and Prototypical Clinical Scenario

Side effects of vasoactive medications are related both to the direct mechanism of action of the agent, as well as the compensatory mechanisms precipitated by them. Concerning side effects of inotropes include dysrhythmias and increased myocardial oxygen demand, whereas vasopressors can cause undesired limitations in blood flow to the gut and kidneys.

Phenylepherine

• Primary Receptor: α₁
• Primary Impact: Increased SVR
• Potentional Side Effects: Reflexive decreased HR
• Protypical Clinical Scenario: Neurogenic shock

Vasopressin

• Primary Receptor: V
• Primary Impact: Increased SVR
• Potentional Side Effects: Decreased splanchnic flow
• Protypical Clinical Scenario: Adjunct for septic shock

Dobutamine

• Primary Receptor: β₁, β₂
• Primary Impact: Increased inotropy
• Potentional Side Effects: Transient decreases in SVR (β_{2 agonism)}
• Protypical Clinical Scenario: Cardiogenic shock from late-stage heart failure

Dopamine (low-dose)

• Primary Receptor: D, β₁
• Primary Impact: Increased inotropy and heart rate
• Potentional Side Effects: Tachydysrhythmias
• Protypical Clinical Scenario: Cardiogenic shock, particularly if bradycardic

Dopamine (high-dose)

• Primary Receptor: D, α₁, β₁>> β₂
• Primary Impact: Increased SVR and inotropy
• Potentional Side Effects: Tachydysrhythmias and decreased splanchnic/renal flow
• Protypical Clinical Scenario: Bradycardic cardiovascular collapse

Epinephrine

• Primary Receptor: α₁, α_2, β₁, β₂
• Primary Impact: Increased SVR and inotropy
• Potentional Side Effects: Tachydysrhythmias and decreased splanchnic flow
• Protypical Clinical Scenario: Anaphylaxis

Norepinephrine

• Primary Receptor: α₁, α₂, β₁>> β₂
• Primary Impact: Increased SVR and inotropy
• Potentional Side Effects: Decreased splanchnic and renal flow
• Protypical Clinical Scenario: Septic shock

References

• Vasu TS, Cavallazzi R, Hirani A, Kaplan G, Leiby B, Marik PE. Norepinephrine or dopamine for septic shock: systematic review of randomized clinical trials. J Intensive Care Med 2012;27:172-8. [PubMed]
• Annane D, Vignon P, Renault A, et al. Norepinephrine plus dobutamine versus epinephrine alone for management of septic shock: a randomised trial. Lancet 2007;370:676-84. [PubMed]
• Myburgh JA, Higgins A, Jovanovska A, Lipman J, Ramakrishnan N, Santamaria J. A comparison of epinephrine and norepinephrine in critically ill patients. Intensive Care Med 2008;34:2226-34. [PubMed]
• Ellender TJ, Skinner JC. The use of vasopressors and inotropes in the emergency medical treatment of shock. Emerg Med Clin North Am 2008;26:759-86, ix. [PubMed]
• De Backer D, Aldecoa C, Njimi H, Vincent JL. Dopamine versus norepinephrine in the treatment of septic shock: a meta-analysis. Crit Care Med 2012;40:725-30. [PubMed]

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