Jesse Dalton, DO
Kent Hospital Emergency Medicine Residency

Abstract

Introduction

Renal infarction is a rare, but clinically important diagnosis due to its significant morbidity and ‎mortality. Atrial fibrillation is a major risk factor for thromboembolic disease that can lead to ‎renal infarction. ‎

Case Presentation

We present a 70-year-old female with a history of atrial fibrillation and aortic valve ‎replacement, who developed an acute renal infarction during her stay in the Emergency ‎Department with complications that eventually led to her death. ‎

Conclusion

Renal infarction is an easily missed diagnosis due to its clinical presentation mimicking ‎common abdominal complaints. It is important for clinicians to keep renal infarction on their ‎differential for patients who present with complaints of flank or abdominal pain and have risk ‎factors for thromboembolic disease. ‎

Introduction

Renal infarction is a rare, but serious diagnosis frequently missed in the Emergency ‎Department due to its often-similar presentation to other more common conditions such as ‎nephrolithiasis or pyelonephritis. Symptoms typically seen with acute renal infarction include ‎flank or abdominal pain frequently associated with nausea, vomiting, and fever. ‎

The main causes of renal infarction include cardioembolic disease, renal artery injury, ‎hypercoagulable states, and idiopathic renal infarction.1,3 Atrial fibrillation is a commonly ‎identified cause of cardioembolic disease, along with cardiomyopathy, endocarditis, and ‎artificial valve thrombi.1‎

Contrast- enhanced computed tomography (CT) is the preferred initial method for ‎diagnosing renal infarction; the classic finding is a wedge-shaped perfusion defect.2 Common ‎laboratory findings include elevated lactate dehydrogenase (LDH), leukocytosis, elevated C-‎reactive protein (CRP), elevated creatinine levels, and hematuria on urinalysis.1,2 ‎

Here, we report a case of a 70-year-old female who presented to the Emergency ‎Department complaining of diffuse abdominal pain. Her initial CT scan was normal. However, ‎‎20 hours later, she acutely decompensated and repeat CT scan showed acute renal infarction ‎associated with perirenal hemorrhage. ‎

Case Report

A 70-year-old female with a past medical history of endocarditis, atrial fibrillation ‎previously on rivaroxaban which was discontinued secondary to gastrointestinal bleeding, left ‎atrial appendage closure device, aortic stenosis status post transcatheter aortic valve ‎replacement, hypertension, hyperlipidemia, congestive heart failure, non-alcoholic ‎steatohepatitis, and gastroesophageal reflux disease who presented to the emergency department ‎complaining of diffuse abdominal pain, nausea, vomiting, and muscle aches for 24 hours prior ‎to arrival. On initial evaluation, the patient was hemodynamically stable and afebrile. Her ‎exam was remarkable for an elderly woman who appeared in moderate distress and had a ‎distended abdomen with moderate right upper quadrant tenderness to palpation. Her ‎electrocardiogram showed a normal sinus rhythm without evidence of ischemic changes. Initial ‎laboratory results showed mild leukopenia of 3.5×103/mcL, 18% bandemia, mild acute kidney ‎injury with creatinine 1.38mg/dL (baseline 0.96mg/dL), elevated transaminases (AST 120IU/L, ‎ALT 78IU/L), and elevated lactate of 3.7mmol/L. A rapid COVID-19 nasopharyngeal swab was ‎obtained and was negative. A CT of the abdomen and pelvis with intravenous contrast was ‎performed and revealed hepatomegaly, mild splenomegaly, mild periportal lymphadenopathy, ‎and a small ventral infra-umbilical hernia without evidence of incarceration (Figure 1). The ‎patient was treated symptomatically with a liter of intravenous (IV) isotonic fluids, IV ‎ondansetron, and IV acetaminophen. Due to the patient’s multiple laboratory abnormalities and ‎persistent symptoms, she was admitted to the hospital for further observation. ‎

Figure 1. Initial CT abdomen and pelvis with IV contrast showing hepatomegaly, mild ‎splenomegaly, mild periportal lymphadenopathy

The patient remained in the emergency department pending hospital bed availability for ‎approximately 20 hours when she suddenly decompensated. She became hypotensive, ‎tachycardic, hypoxic, altered, and her abdomen became distended. She was intubated for ‎decreased mental status. A right internal jugular central venous catheter was placed and she ‎was started on norepinephrine. A repeat CT scan of her abdomen was performed, which showed ‎a large area of perirenal hemorrhage which extended above and below the left kidney with ‎patchy enhancement throughout the kidney, suggestive of infarction (Figure 2). The patient was ‎taken for emergent left renal artery embolization by interventional radiology and transferred to ‎the intensive care unit (ICU) for further management. ‎

Figure 2. Repeat CT abdomen and pelvis with IV contrast approximately 20 hours after ‎initial CT scan now with a large area of perirenal hemorrhage which extends above and below ‎the left kidney with patchy enhancement throughout the kidney suggestive of infarction

Upon arrival in the ICU, the patient remained hypotensive requiring vasopressors. ‎Repeat laboratory results were significant for a lactic acid of 15.1mmol/L, hemoglobin of ‎‎6.2g/dL, and platelets of 36×103/mcL. She was started on a bicarbonate infusion for her acidosis ‎and she was transfused three units of packed red blood cells, two units of fresh frozen plasma, ‎and one unit of platelets. Blood cultures obtained on initial arrival in the emergency ‎department both resulted positive for methicillin sensitive Staphylococcus Aureus. Nafcillin ‎antibiotic therapy was initiated. A transthoracic echocardiogram was performed and showed an ‎ejection fraction of 65-70%, trace mitral and tricuspid regurgitation, and a bioprosthetic aortic ‎valve without evidence of vegetation. ‎

On day two of admission, her abdominal distension continued to worsen and a non- ‎contrast enhanced CT of the abdomen was performed, showing the left infracted kidney with ‎persistent stable retroperitoneal hemorrhage, persistent contrast in the parenchyma of the right ‎kidney. Additionally, it showed evidence of probable splenic infarct, not previously seen on ‎prior imaging studies.‎

The urology and general surgery services were consulted and determined she was not a ‎surgical candidate for nephrectomy or splenectomy due to hemodynamic instability despite ‎vasopressor support. The patient was anuric and her creatinine continued to rise daily. She ‎eventually required hemodialysis on hospital day three for anuria and increasing ventilator ‎oxygen requirements, likely secondary to fluid overload. ‎

The patient had a transesophageal echocardiogram performed on hospital day five, ‎which showed ejection fraction of 70%, left ventricular hyperdynamic systolic function, severe ‎left atrial enlargement, moderate mitral regurgitation, and no evidence of endocarditis. The ‎patient continued to deteriorate daily despite antibiotic therapy, continued vasopressors, and ‎dialysis. On hospital day six, her family decided to pursue comfort measures and she died later ‎that evening. ‎