Acute Pyelonephritis Associated with Ruptured Abdominal Aortic Aneurysm: An Unusual Presentation

We describe a rare presentation of acute pyelonephritis associated with a ruptured abdominal aortic aneurysm. A 68-year-old female presented to the emergency department with a 3 day history of cystitis. General examination revealed the acute onset of pain in the left flank accompanied by fever and chills. Blood tests revealed leucocytosis 25,400×10(9)/L and C-reactive protein 495 mg/L (<6.1), while urinary sediment analysis revealed many leucocytes and gram-negative bacteria. The patient was admitted with acute pyelonephritis. On the third day of admission, the urine culture isolated Escherichia coli sensitive to the antibiotic prescribed; however, the patient clinically deteriorated. A computed tomography scan revealed a ruptured abdominal aortic aneurysm involving the left renal artery. The patient underwent an exploratory laparotomy but uncontrollable haemorrhage led to a fatal outcome. This case highlights a rare case of acute pyelonephritis associated with a ruptured abdominal aortic aneurysm. A computed tomography scan or abdominal ultrasound should be considered whenever a patient has acute pyelonephritis with a C-reactive protein >400 mg/L in order to exclude complications and other potentially fatal pathologies. LEARNING POINTS: Acute pyelonephritis can lead to a ruptured abdominal aortic aneurysm. There should be a high index of suspicion for other concomitant acute pathologies in patients with pyelonephritis and a C-reactive protein >400 mg/L. A low threshold for abdominal imaging, either a computed tomography scan or abdominal ultrasound, may allow for the diagnosis of pathologies with a high mortality rate, such as a ruptured abdominal aortic aneurysm, at an early stage and thus result in better prognosis.