Opening the microcirculation: can vasodilators be useful in sepsis?

Area of Science:

• Critical care medicine
• Hemodynamics
• Microcirculation research

Background:

• Sepsis is characterized by microcirculatory dysfunction, leading to impaired tissue perfusion and oxygen extraction.
• This dysfunction may involve shunting of oxygenated blood past hypoxic tissue beds.
• Vasodilator therapy could potentially improve oxygen delivery by recruiting these shunted units.

Purpose of the Study:

• To review the evidence for vasodilator therapy improving microcirculatory function in sepsis.
• To assess the impact of vasodilators on tissue oxygenation and perfusion in septic states.

Main Methods:

• A Medline literature search was performed using keywords for vasodilators and sepsis-related terms.
• Included studies (animal and clinical) demonstrated vasodilator effects on regional oxygen transport variables.
• Investigated vasodilators included prostacyclin, pentoxifylline, N-acetyl-cysteine, and nitric oxide donors.

Main Results:

• Prostacyclin and nitric oxide donors showed improved tissue perfusion and oxygen extraction in experimental sepsis.
• Clinical studies with prostacyclin demonstrated similar beneficial effects.
• Nitric oxide donors have been shown to recruit microcirculation in resuscitated septic patients.

Conclusions:

• Vasodilators, particularly prostacyclin and nitric oxide donors, show promise in improving microcirculatory function in sepsis.
• Evidence suggests these agents can enhance tissue perfusion and oxygen extraction.
• Further research is needed to determine if these microcirculation-recruiting therapies improve patient outcomes.