Ammonia is elevated in the following conditions: liver disease, urinary tract infection with distention and stasis, Reye syndrome, inborn errors of metabolism including deficiency of enzymes in the urea cycle, HHH syndrome (hyperammonemia-homocitrullinuria, hyperornithinemia), some normal neonates (usually returning to normal in 48 hours), total parenteral nutrition, ureterosigmoidostomy, and sodium valproate therapy. Ammonia determination is indicated in neonates with neurological deterioration, subjects with lethargy and/or emesis not explained, and in patients with possible encephalopathy.
Ammonia measurements are mainly of use in the diagnosis of urea cycle deficiencies (any neonate with unexplained nausea, vomiting, or neurological deterioration appearing after first feeding), and they play an important part in the detection of Reye syndrome.
In Reye syndrome threefold increases in AST, ALT and plasma ammonia are required for diagnosis with/or the diagnostic liver biopsy findings. Ammonia levels increase characteristically early; plasma ammonia ≥100 μg/dL reflects severe hepatic changes. Prothrombin time is increased in essentially all patients, prototypically three seconds longer than the control. Bilirubin is usually normal. Glucose should be monitored; hypoglycemia may develop. Hyperosmolality and acid-base imbalance may develop, lactate may increase, CK may increase and CK-MB may be elevated. Uric acid may increase. Increased ammonia and prolonged prothrombin time provide indicators of disease progression.
How Do I Get My Lab?
How Do I Get My Lab?
Place Your Order
Choose and purchase the lab tests you want. You will immediately receive a purchase confirmation email, and then an email containing your requisition number once the order is processed by our team.
Find and Visit a Lab
Locate the nearest Labcorp location to you and bring your requisition number. If you need help finding a location, visit here.
Receive Your Results
Depending on the test(s) you've purchased, you should receive an email with your results within 5-7 business days.
The most affordable labs online.
We offer the best priced labs online. We do this with an exclusive partnership with Labcorp that allows us to lower prices compared to our competitors.