Hyperammonemia in Urinary Tract Infections

OBJECTIVES: The present study investigated the incidence of hyperammonemia in urinary tract infections and explored the utility of urinary obstruction relief and antimicrobial administration to improve hyperammonemia. METHODS: This was an observational study. Subjects were patients who were diagnosed with urinary tract infection and hospitalized between June 2008 and June 2009. We measured plasma ammonia levels on admission in patients who were clinically diagnosed with urinary tract infection and hospitalized. We assessed each patient's level of consciousness on admission using the Glasgow Coma Scale (GCS) and performed urine and blood cultures. We also assessed hearing prior to hospitalization using the Eastern Cooperative Oncology Group performance status (ECOG-PS). In cases with high ammonia levels on admission, plasma ammonia and GCS were measured 24 hours and 5–7 days later. RESULTS: Sixty-seven candidates were enrolled; of these, 60 cases (89.6%) with bacterial cell counts ≥10(4) CFU/mL were studied. Five cases (8.3%) presented with high plasma ammonia levels. Cases with hyperammonemia were significantly more likely to present with low GCS scores and urinary retention rate. All five cases received antimicrobial therapy with an indwelling bladder catheter to relieve urinary retention. The case 5 patient died shortly after admission due to complicated aspiration pneumonia; in the remaining cases, plasma ammonia levels were rapidly normalized and the level of consciousness improved. CONCLUSIONS: The occurrence of hyperammonemia in urinary tract infections is not rare. The cause of hyperammonemia is urinary retention obstruction. Therefore, along with antimicrobial administration, relief of obstruction is important for the treatment of hyperammonemia caused by this mechanism.