SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Bariatric surgery is now a popular weight reduction method for obesity-related morbidity and mortality. Recently, cases with hyperammonemia after gastric bypass surgery have been reported. CASE PRESENTATION: A 66-year-old woman with a history of non-alcoholic fatty liver disease, remote Roux-en-Y gastric bypass surgery, and multiple abdominal surgeries presented with septic shock from abdominal wound infection. Her hospital course was complicated by recurrent episodes of sepsis and inadequate oral intake leading to malnutrition which resulted in difficulty in closing her abdominal wounds. The patient was transferred to the medical intensive care unit for septic shock and altered mental status on hospital day 60th. Overall her clinical condition improved within several days after broad antibiotics and vasopressors were started for septic shock. Despite her clinical improvement, she remained obtunded and minimally responsive to stimuli. Ammonia level was 92 umol/L, lactulose and rifaximin were started empirically for hyperammonemic encephalopathy. CT head and MRI brain were not revealing. An electroencephalogram showed triphasic waves consistent with metabolic encephalopathy. In spite of 3-4 loose stools with lactulose and rifaximin, her mental status remained unchanged. Repeat ammonia level was elevated to 145 umol/L. Post gastric bypass hyperammonemic syndrome was suspected, therefore L carnitine, multivitamin, and zinc supplement were started. The patient’s mental status started improving from the next day. Ammonia level decreased to 53 umol/L subsequently. The patient had wound closure on hospital day 66th, and she was subsequently transferred to the general floor. DISCUSSION: Since extensive work-up did not reveal a cause of altered mental status, our hypothesis was that post gastric bypass micronutrient deficiency provoked hyperammonemia. Since she had multiple polymicrobial infection, urea forming bacterial infection could have been other contributing factor. This hypothesis was supported by improvement of her hyperammonemic encephalopathy after treatment of sepsis and supplement of micronutrient. Hyperammonemia following bariatric surgery in the context of non-cirrhotic liver condition is challenging. Our case had previously reported common features: preceding gastric bypass surgery, hyperammonemic encephalopathy, absence of cirrhosis, hypoalbuminemia, and nutritional complications. Early suspicion of this pathology and follow up of ammonia was successful. CONCLUSIONS: Postoperative malnutrition exaggerates post gastric bypass nutritional complication and could lead to hyperammonemic encephalopathy following bariatric surgery. Clinicians should have a high index of suspicion for this rare complication and evaluate ammonia level. Reference #1: Fenves AZ, Shchelochkov OA, Mehta A. Obesity. 2015 Apr; 23(4):746-9. Hyperammonemic syndrome after Roux-en-Y gastric bypass. DISCLOSURES: No relevant relationships by Toshiki Kuno, source=Web Response No relevant relationships by Young Im Lee, source=Web Response No relevant relationships by Reiichiro Obata, source=Web Response