Gas in hepatic veins: a rare and critical presentation of emphysematous pyelonephritis.

Although emphysematous pyelonephritis has been recognized for more than a hundred years, the actual etiology is still unknown. Glucose fermentation has been implicated as a mechanism of gas formation. We report a case of emphysematous pyelonephritis in which real-time ultrasonography demonstrated intravascular gas bubbles originating in the involved kidney, and passing into the inferior vena cava and hepatic veins. Gas from the affected kidney was analyzed by chromatography; the result showed hydrogen 10.5%, carbon dioxide 39%, nitrogen 49.6% and oxygen 0.8%. The clinical presentation and the results of gas analysis implicate a critical condition that bacteria proliferated rapidly by mixed acid fermentation of glucose. Additionally, the finding of gas production and transportation could explain the previous hypothesis of gas transport. In this critical situation immediate drainage with medical intervention is indicated to treat this life threatening condition.