Thoracic Epidural Anesthesia Attenuates Endotoxin-induced Impairment of Gastrointestinal Organ Perfusion

Abstract

Systemic inflammation can be associated with a redistribution of organ blood flow and a decrease in gastrointestinal perfusion. Regional sympathetic blockade by means of thoracic epidural anesthesia (TEA) has been shown to improve intestinal microcirculation during systemic inflammation. This study tests the hypothesis that during systemic inflammation, TEA attenuates the impairment of gastrointestinal organ perfusion without compromising blood flow to vital organs. Eighteen rats were anesthetized, hemodynamically monitored, and mechanically ventilated with room air. By using fluorescent microspheres, organ perfusion was quantified at baseline, 30 min after the start of epidural infusion of either 2% lidocaine (TEA) or normal saline (control), and after 60 and 120 min of intravenous Escherichia coli lipopolysaccharide infusion in TEA and control animals. Blood pressure initially was lower in TEA animals, but it was comparable to controls during endotoxemia. Gastrointestinal organ perfusion significantly decreased after 120 min of endotoxemia in the controls but not in the TEA animals (-23 +/- 27% vs. -6 +/- 26%, mean +/- SD, P < 0.05). Perfusion of the vital organs such as the heart, brain, liver, and kidneys was comparable between controls and TEA after 120 min of endotoxemia. TEA attenuates the impairment of gastrointestinal organ perfusion during endotoxemia. Hence, the protective effects of TEA on intestinal microcirculation during endotoxemia may be due to a higher total organ blood flow compared with endotoxemic control animals. Furthermore, in the course of endotoxemia, TEA provides hemodynamic stability and does not compromise blood flow to vital organs.