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Case Reports in Critical Care
Volume 2017, Article ID 8724810, 4 pages
Case Report

Ornithine Transcarbamylase Deficiency: If at First You Do Not Diagnose, Try and Try Again

1Department of Critical Care Medicine, Mayo Clinic, Jacksonville, FL, USA
2Department of Nutritional Services, Mayo Clinic, Jacksonville, FL, USA
3Department of Clinical Genomics, Mayo Clinic, Jacksonville, FL, USA
4Division of Hospital Internal Medicine, Mayo Clinic, Jacksonville, FL, USA

Correspondence should be addressed to Nicole E. Joyce; ude.oyam@1elociN.ecyoJ

Received 5 August 2017; Revised 21 October 2017; Accepted 6 November 2017; Published 27 November 2017

Academic Editor: Kurt Lenz

Copyright © 2017 Christan D. Santos et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Ornithine transcarbamylase (OTC) deficiency is well known for its diagnosis in the neonatal period. Presentation often occurs after protein feeding and manifests as poor oral intake, vomiting, lethargy progressing to seizure, respiratory difficulty, and eventually coma. Presentation at adulthood is rare (and likely underdiagnosed); however, OTC deficiency can be life-threatening and requires prompt investigation and treatment. Reports and guidelines are scarce due to its rarity. Here, we present a 59-year-old woman with a past history of irritable bowel syndrome who underwent a reparative operation for rectal prolapse and enterocele. Her postoperative course was complicated by a bowel perforation (which was repaired), prolonged mechanical ventilation, tracheostomy, critical illness myopathy, protein-caloric malnutrition, and altered mental status. After standard therapy for delirium failed, further investigation showed hyperammonemia and increased urine orotic acid, ultimately leading to the diagnosis of OTC deficiency. This case highlights the importance of considering OTC deficiency in hospitalized adults, especially during the diagnostic evaluation for altered mental status.