Effects of catecholamines on microcirculation during general inhalation anesthesia.

Area of Science:

• Anesthesiology and Critical Care Medicine
• Cardiovascular Research
• Surgical Oncology

Background:

• General anesthesia with sevoflurane can impact hemodynamic stability and microcirculation.
• Vasoactive drugs like norepinephrine and dobutamine are used to manage hemodynamics during surgery.
• The effect of these agents on sublingual microcirculation under sevoflurane anesthesia requires further investigation.

Purpose of the Study:

• To evaluate the impact of clinical doses of norepinephrine and dobutamine on sublingual microcirculation.
• To assess systemic hemodynamic changes induced by these infusions during sevoflurane anesthesia.
• To compare the effects of norepinephrine and dobutamine on microcirculatory parameters.

Main Methods:

• Prospective study involving 20 patients undergoing elective breast cancer surgery.
• Continuous infusions of norepinephrine (0.1 μg/kg/min) followed by dobutamine (5 μg/kg/min) were administered.
• Hemodynamic parameters (esophageal Doppler) and sublingual microcirculation (sidestream darkfield) were assessed before and after each infusion.

Main Results:

• No significant changes were observed in total vessel density, perfused vessel density, proportion of perfused vessels, or microvascular flow index.
• Both norepinephrine and dobutamine significantly increased mean arterial pressure compared to baseline.
• Dobutamine, but not norepinephrine, significantly increased peak velocity and stroke volume index.

Conclusions:

• Clinical dosages of norepinephrine and dobutamine did not alter sublingual microcirculation during sevoflurane general anesthesia.
• Despite no microcirculatory changes, systemic hemodynamic effects were observed.
• These findings suggest a dissociation between systemic hemodynamics and microcirculatory perfusion under these conditions.