SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Wünderlich syndrome (WS) is a rare presentation of hypovolemic hemorrhagic shock. It is a fatal disease described as a syndrome of spontaneous non-traumatic subcapsular and retroperitoneal hemorrhage. The etiology of WS is varied, with renal causes including malignancy being the most common, followed by renal vasculature abnormalities, vasculitis, cystic rupture, pyelonephritis, and idiopathic. The appropriate treatment depends on the accuracy of diagnosis and precise determination of its cause. To our knowledge, this is the first case report of WS due to acute pyelonephritis in a patient with congenital solitary kidney and Jehovah's Witness religious beliefs which impacted his care. CASE PRESENTATION: A 77 year old male with a two day history of flank pain accentuated on the right side, fevers, and confusion presented as critically ill and requiring vasopressor support. His medical history comprises prostate cancer in remission and atrial fibrillation on aspirin. He was diagnosed clinically with pyelonephritis, and culture positive urinary tract infection and sepsis with Escherichia coli. The initial hemoglobin was of 10.3 g/dL. Computed tomography (CT) of the abdomen showed nonspecific stranding and a solitary right kidney. He clinically deteriorated prompting repeat CT imaging that showed a large right perirenal hematoma with retroperitoneal blood. He underwent emergent coil angioembolization of a hemorrhagic branch of the inferior pole renal artery. His hemoglobin of 4 g/dL recovered with erythropoietin and intravenous iron. He briefly required hemodialysis for his acute kidney injury. The patient survived and the function of his congenital solitary kidney was preserved. DISCUSSION: The classic signs of WS include Lenk’s triad of flank pain, abdominal mass, and hypovolemic shock. However, in only 20% of cases, all three symptoms present. Acute onset of flank pain is the most common symptom. Although pyelonephritis is a rare cause of WS, in our case we believe that bleeding diathesis and etiology of WS was driven by cytokine induced endothelial damage from pyelonephritis along with aspirin induced platelet dysfunction. CT is preferred for the initial imaging workup. Angioembolization is a minimally invasive treatment modality for acute hemorrhage. Exploratory laparotomy or nephrectomy is typically recommended if malignancy is suspected. CONCLUSIONS: WS requires prompt recognition to prevent death from exsanguination. Shock is relatively common with WS, however, surgical exploration is not absolutely necessary with the advent of angioembolization. The unconventional treatment method with erythropoietin instead of blood may be considered in patients with Jehovah’s Witness religious beliefs. Reference #1: Katabathina VS, Katre R, Prasad SR, Surabhi VR, Shanbhogue AK, Sunnapwar A. Wunderlich syndrome: cross-sectional imaging review. J Comput Assist Tomogr. 2011;35(4):425-33. Reference #2: Chen YC, Lin YC. Wunderlich syndrome. QJM. 2013;106(2):187-8. Reference #3: Chamarthi G, Koratala A. Wunderlich syndrome. Clin Case Rep. 2018;6(9):1901-1902. DISCLOSURES: No relevant relationships by Francois Kaleta, source=Web Response No relevant relationships by Mitra Sahebazamani, source=Web Response No relevant relationships by Pratyaksha Sankhyan, source=Web Response