Circulatory effects of dexmedetomidine in early sepsis: a randomised controlled experimental study.

We designed this experimental study with a view to evaluate the effects of dexmedetomidine (DEX) on cardiac performance and systemic and peripheral hemodynamics in healthy and early-stage endotoxemia swine models. Our study hypothesis was that DEX can ensure hemodynamic stability during the course of endotoxemia. Thirty-two male pigs (25-27 kg) were assigned into four groups: (1) no intervention (group A), (2) DEX 0.8 μg/kg was administered in non-septic animals (group B), (3) sepsis induced by intravenous Escherichia coli endotoxin (group C) and (4) DEX 0.8 μg/kg was administered in septic animals (group D). Hemodynamic parameters such as heart rate, mean blood pressure, central venous pressure, pulmonary artery pressures, pulmonary artery occlusion pressure, pulmonary vascular resistance and cardiac output were continuously recorded. Central venous oxygen saturation was also measured in order to obtain a complete evaluation of cardiovascular response to sepsis. Heart rate was decreased, whilst mean arterial pressure decrease was alleviated after DEX administration in septic animals. In addition, central venous pressure was stable in animals with sepsis after DEX infusion. Sepsis dramatically elevated pulmonary function indicators but DEX succeeded in ameliorating this effect. The important decrease measured in central venous oxygen saturation in both sepsis groups reflected the decreased perfusion of tissues that takes place at the end of early sepsis. Our findings support the hypothesis that DEX has beneficial effects on heart rate and pulmonary artery pressure, whilst reduction in systemic blood pressure occurs at acceptable levels.