SESSION TITLE: Critical Care Cases III
SESSION TYPE: Affiliate Case Report Slide
PRESENTED ON: Wednesday, October 28, 2015 at 11:00 AM - 12:15 PM
INTRODUCTION: Hyperammonaemia associated encephalopathy is commonly caused by underlying liver disease; however, in rare cases of normal liver function the underlying diagnosis can be challenging. This delay in diagnosis can be life threatening.
CASE PRESENTATION: A 52 year old female with a history of Roux-en-Y gastric bypass was found non-responsive at home. The night before she was disoriented and had two episodes of hematemesis. On arrival to the hospital she was intubated and remained hemodynamically stable on minimal respiratory support. Laboratory studies revealed an ammonia level of 433 and deficiency in most amino acids. Her albumin, liver function, INR, valproic acid level, urine orotic acid level, CT and MRI head, lumbar puncture, urine analysis and liver biopsy were unremarkable. EGD revealed a superficial stomach ulcer. CTA abdomen showed tortuosity and diffuse dilation of the ciliac axis which was suggestive of portal-systemic shunt; however no direct shunt was identified. The patient was started on lactulose, rifaximin and golytely. Her ammonia levels decreased and mental status improved over the next 72 hours at which time she was extubated.
DISCUSSION: Hyperammonaemia is a well-established cause of encephalopathy and is most commonly associated with liver disease; however urea cycle defects, organic acidemias, Reye’s syndrome, infections with urea-splitting organisms, drugs and portal-systemic shunts can also be associated with this condition. In our case there was no evidence of liver disease and urine orotic acid levels were normal. Infectious workup and drug screens were unremarkable. The patient’s condition was likely a result of increased ammonia levels from her gastrointestinal bleed in conjunction with severe malnutrition from prior gastric bypass surgery. Her malnutrition was confirmed by the deficiency in amino acids which are essential for the regulation of ammonia. Although no direct portal-systemic shunt was identified, her CTA findings were highly suspicious for an occult shunt that was not visible on imaging. In the presence of a portal-systemic shunt, blood would bypass the hepatic sinusoids and directly re-enter the systemic circulation resulting in hyperammonaemia.
CONCLUSIONS: This case illustrates the importance of early recognition of life threatening hyperammonaemia and the need for further workup in the presence of normal liver function.
Reference #1: Clay A, Hainline B. Hyperammonemia in the ICU. CHEST. 2007;132(4)
DISCLOSURE: The following authors have nothing to disclose: Maykol Postigo Jasahui, Kyle Brownback
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