Emphysematous pyelonephritis is a severe acute necrotizing parenchymal renal infection caused by gas-forming bacteria. Diabetes mellitus and urinary tract obstruction are the two most predisposing factors. The initial diagnosis can only be made by emergent department ultrasound and confirmed by abdominal CT scan. We reported a case of emphysematous pyelonephritis diagnosed by bedside emergency department ultrasound allowing a more rapid diagnosis and subsequent treatment. A 84 years-old female patient, history of diabetics with insulin control and hypertension, was noted general malaise, poor appetite, high blood sugar noted for about 1 week. Lab data showed WBC 18600 S93 B4 Glu 248 BUN/Cr 65/3.0 CRP 43.09. KUB showed an
opaque shadow in right flank, mottled appearance of right kidney shadow. A bedside emergency department ultrasound was performed and showed reverberation of air within the right kidney that obscured the entire kidney shadow, right side pleural effusion and right liver cyst. An emergency abdominal CT scan without contrast was done immediately and showed prominent air collection in right renal parenchyma and perirenal space with a big calcified stone in right renal pelvis, right liver cyst and right pleural effusion. Finally urologist was consulted and operation had arranged. Operation findings showed necrotic change of entire right kidney with a lot of pus and right upper ureter stone. Right subcapsular nephrectomy was done.