Abstract Introduction Ammonia levels are often checked as a part of evaluation of Altered Mental Status. High levels in the absence of liver disease has been reported to be caused by obstructive/complicated urinary infection by Urease producing organisms (1,2, 3) and should be followed by investigations into urinary anatomy in the absence of obvious abnormalities. Case Presentation A 75 year old female with history of Diabetes and CLL in remission presented to Emergency room for evaluation of word finding difficulty and altered mental status. CT Angio of head and neck ruled out a stroke, further workup showed a high ammonia level (101 uMol/L) and urinalysis suggestive of infection. Patient had no history of liver disease and normal liver enzymes, was not on medicines commonly known to cause hyperammonemia (valproate, topiramate etc.). CT of abdomen and pelvis showed non distended bladder with wall thickening concerning for cystitis, asymmetric bilateral perinephric stranding, and a 9cm eccentric filling defect in right ureter. Blood Cultures were positive for Proteus mirabilis, which was deemed to be likely explanation of hyperammonemia. Ammonia levels normalised within 48 hours of fluid and antibiotic therapy. Urology recommended dedicated CT urogram and follow up after resolution of sepsis. Discussion Hyperammonemic encephalopathy can be the primary presentation of gram negative septicaemia due to urease producing organisms, almost always in the context of complicated urinary anatomy, likely secondary to ammonia absorption proximal to an obstruction. High ammonia levels in context of urosepsis should prompt consideration of urinary tract imaging to prevent recurrences. References(1) Drayna CJ, Titcomb CP, Varma RR, Soergel KH. Hyperammonemic encephalopathy caused by infection in a neurogenic bladder. N Engl J Med. 1981 Mar 26;304(13):766-8. doi: 10.1056/NEJM198103263041307. PMID: 7464886.(2) Sinha B, Gonzalez R. Hyperammonemia in a boy with obstructive ureterocele and proteus infection. J Urol. 1984 Feb;131(2):330-1. doi: 10.1016/s0022-5347(17)50366-3. PMID: 6699967(3) Kato K, Okumura K, Suzuki S, Matsuyama A, Hirabayashi H, Hattori R. Hyperammonemic encephalopathy associated with post-radiotherapy vesicointestinal fistula following cervical cancer. J Obstet Gynaecol Res. 2021 Aug;47(8):2790-2793. doi: 10.1111/jog.14865. Epub 2021 May 26. PMID: 34038978.(4)Samtoy B, DeBeukelaer MM. Ammonia encephalopathy secondary to urinary tract infection with Proteus mirabilis. Pediatrics. 1980 Feb;65(2):294-7. PMID: 6444460. This abstract is funded by: None
Seth et al. (Fri,) studied this question.