Heightened suspicion and rapid evaluation with CT for early diagnosis of partial renal infarction

Background and Objective: Although renal infarction has been well studied and clearly defined, it remains greatly underdiagnosed, resulting in significant morbidity. Acute segmental renal infarction is a diagnosis even more problematic, as the problem can appear insidiously and masquerade as other entities including stone, infection, and even tumor. The clinical manifestations and evaluation of partial renal infarction in our patients were reviewed. Patients and Methods: Seven patients presenting to the emergency department who were subsequently found to have partial renal infarction were identified from the 5-year records of a single institution. Patients were evaluated for presenting complaints, physical findings, temperature, and blood pressure. Laboratory analysis consisted of a complete blood count (CBC); measurements of creatinine, lactate dehydrogenase (LDH), aspartate transaminase/alanine transaminase (AST/ALT), and alkaline phosphatase; and urinalysis. The sequence of the work-up was recorded, as well as time to diagnosis. The etiology of infarction was identified for all patients. Results: All seven patients were eventually discovered to have partial renal infarction as a result of dysrhythmia (N = 4), mural thrombus (N = 2), or septic emboli (N = 1). The average time to diagnosis was 65.2 hours with a range of 9.5 to 168 hours. The chief complaint was flank pain (N = 3), nonspecific abdominal pain (N = 2), left lower-quadrant pain (N = 1), and mental status change (N = 1). The presenting signs and symptoms included abdominal tenderness (N = 4), nausea and vomiting (N = 4), temperature >100.5 degrees F (N = 3), and hypertension (N = 3). Laboratory studies revealed a white cell count >11,000/mu L in six, microhematuria in four, proteinuria in four, elevated LDH in all patients, elevated AST/ALT in two, and elevated alkaline phosphatase in one. The work-up varied by presentation, but definitive diagnosis was made by CT in all five patients scanned and by angiography in two. Angiography confirmed the CT findings in four of the five patients. Conclusion: In evaluating partial renal infarction, a strong clinical suspicion is necessary. We found a history of dysrhythmia or other cardiac disease, the presence of abdominal or flank pain, fever with an elevated white cell count, and an elevated LDH to be clinically significant, and their presence should alert the clinician to the possibility of renal infarction. Once a degree of suspicion exists, early evaluation with CT should speed the diagnosis and effect decreased morbidity.