Treatment of a case of emphysematous pyelonephritis that presented with acute abdomen and pneumoperitoneum: a case report

BACKGROUND: Emphysematous pyelonephritis is a severe, life-threatening infection of the renal parenchyma and perinephric tissues. This condition is primarily encountered in patients with diabetes mellitus or ureteral obstruction, and is characterized by the production of intrarenal and perinephric gas. Emphysematous pyelonephritis is associated with a high degree of morbidity and a high mortality rate. CASE PRESENTATION: A 72-year-old woman with a history of diabetes mellitus, hypertension, and renal calculi was referred to our emergency department following 6 days of abdominal pain. She suddenly developed pain in the entire abdomen, and was transferred. Physical examination was a distended abdomen with hypoactive bowel sounds. The tenderness was diffuse, but was most prominent in the right upper abdominal quadrant; moreover, rebound tenderness was noted. Laboratory tests revealed a white blood cell count of 4,480/mm(3), platelet count of 17,000/mm(3), creatinine level of 1.64 mg/dl, and serum glucose level of 603 mg/dl. Abdominal computed tomography indicated the presence of free air in the intraperitoneal cavity and right perirenal space, hydronephrosis of the right kidney, and stones in the right distal ureter. After 1 hour, the vital signs changed and she appeared to become drowsy. Therefore, the patient was transferred to the operation room for laparotomy. On exploration of the abdomen, 1.5 L of pus-colored fluid was removed. Although the abdominal viscera and pelvic organs were examined, hollow viscus perforation site could not be observed. Moreover, tissue necrosis and a perforation site were identified at the superior border of the right kidney. Thus, emphysematous pyelonephritis was diagnosed and she underwent right radical nephrectomy. After the surgery, the patient was admitted to the intensive care unit for postoperative management. Follow-up CT performed after 10 days showed fluid collection and hematoma at the nephrectomy site. Hence, percutaneous drainage was performed. Another follow-up computed tomography after 3 weeks indicated that the fluid collection at the nephrectomy site had nearly disappeared. CONCLUSIONS: We believe that cases with free intraperitoneal air should promptly undergo laparotomy to identify the cause of the pneumoperitoneum. Moreover, an immediate nephrectomy may be effective for the treatment of emphysematous pyelonephritis in cases with poor prognostic factors.