Beschreibung:
<jats:p>The relationship between flow motion and tissue oxygenation was investigated during hemorrhage/retransfusion with and without dopamine in 14 pigs. During 45% bleed, jejunal microvascular hemoglobin O<jats:sub>2</jats:sub>saturation (HBjO<jats:sub>2</jats:sub>) and mucosal tissue Po<jats:sub>2</jats:sub>(Po<jats:sub>2</jats:sub><jats:sub>muc</jats:sub>) were recorded in seven control and seven dopamine-treated animals. Mean arterial pressure and systemic O<jats:sub>2</jats:sub>delivery decreased during hemorrhage and returned to baseline after retransfusion. Hemorrhage decreased Po<jats:sub>2</jats:sub><jats:sub>muc</jats:sub>from 33 ± 2.8 to 13 ± 1.6 mmHg and HBjO<jats:sub>2</jats:sub>from 53 ± 4.9% to 32 ± 3.9%, respectively, in control animals. During reperfusion, Po<jats:sub>2</jats:sub><jats:sub>muc</jats:sub>and HBjO<jats:sub>2</jats:sub>remained low. Dopamine increased Po<jats:sub>2</jats:sub><jats:sub>muc</jats:sub>from 28 ± 4.3 to 45 ± 4.6 mmHg and HBjO<jats:sub>2</jats:sub>from 54 ± 5.7% to 69 ± 1.5% and attenuated the decrease in Po<jats:sub>2</jats:sub><jats:sub>muc</jats:sub>and HBjO<jats:sub>2</jats:sub>during hemorrhage. After retransfusion, dopamine restored Po<jats:sub>2</jats:sub><jats:sub>muc</jats:sub>and HBjO<jats:sub>2</jats:sub>to baseline. Control animals developed rhythmic HBjO<jats:sub>2</jats:sub>oscillations with increasing amplitude (frequency, 4.5 to 7.6 cycles/min) and showed an inverse relationship between Po<jats:sub>2</jats:sub><jats:sub>muc</jats:sub>and HBjO<jats:sub>2</jats:sub>oscillation amplitude. Dopamine prevented regular flow motion. The association between decreased Po<jats:sub>2</jats:sub><jats:sub>muc</jats:sub>and increased oscillations in HBjO<jats:sub>2</jats:sub>after normalization of systemic hemodynamics and O<jats:sub>2</jats:sub>transport in control animals suggests a cause-and-effect relationship between low tissue Po<jats:sub>2</jats:sub>and flow motion activity within the jejunal microcirculation.</jats:p>