Case Presentation: Hypertensive Emergency is a common condition encountered in the hospital. Identifying the underlying etiology is very important because it can alter clinical outcome and management.A 42-year-old man with History of Hypertension presented to ER with Exertional Shortness of breath. He admitted to taking his blood pressure medication inconsistently. While in Emergency Room, he was found to have blood pressure of 215/163 with bilateral lower extremity edema. Chest x-ray showed cardiomegaly with bibasilar interstitial prominence. On Basic metabolic panel creatinine was found to be 10.14 with unknown baseline, but patient denied any history of kidney dysfunction. Also, patient had hemoglobin of 8.5 with unknown baseline. Patient was admitted to ICU and initially managed with Intravenous furosemide and nitroglycerine drip for Hypertensive emergency with flash pulmonary edema, which resolved his shortness of breath. However, blood pressure remained elevated so nicardipine drip was started. During course of hospital stay patient BP improved so nicardipine drip was tapered and Various oral medications were continued. Over the next few days creatinine continued to rise to 13.41 and patient was developing metabolic acidosis from Acute kidney injury. Also, his Hemoglobin dropped to 7.3. This clinical picture was thought to be secondary to end organ damage to kidneys from hypertension, so nephrology was consulted for potential initiation of dialysis. However, due to acute onset of presentation secondary causes were being considered, so plan for renal biopsy were made. For work of anemia serum LDH level was elevated (1134), haptoglobin decreased (<15) consistent with hemolysis. Moreover, peripheral smear showed schistocytes, platelet count was 87, and results of kidney biopsy showed thrombotic microangiopathy. Due to clinical picture of uncontrolled blood pressure, hemolysis, schistocytes, thrombocytopenia and thrombotic microangiopathy, diagnosis of Atypical Hemolytic Uremic syndrome was made. Next, a plan was made to hold dialysis and initiate treatment with eculizumab. Over the course of next few months blood pressure was well controlled on oral medications, creatinine came down to 3.5, hemoglobin improved to 12, and platelet count normalized.
Discussion: Atypical Hemolytic Syndrome is a rare genetic disorder that primarily effects kidney function. It occurs by unregulated compliment activation leading to thrombi formation in small blood vessels. AHUS has three features hemolytic anemia, thrombocytopenia, and renal failure. Uncontrolled blood pressure can also result when thrombi block small vessels in kidney, causing elevation of renin. Also, renal failure occurs secondary to thrombi causing ischemia to the kidneys. Eculizumab is recombinant humanized monoclonal that inhibits complement cascade, which makes this drug effective treatment for AHUS.
Conclusions: This case highlights importance of clinicians identifying underlying etiology in commonly encountered clinical presentation. By identifying underlying etiology, this case was successfully managed with drug therapy as opposed to commitment to dialysis, resulting in improved patient quality of life.