Ammonia (NH3) Lab Values

Overview Ammonia Normal Value Range Pathophysiology Special considerations Too High: Causes, Symptoms, Treatments Too Low: Causes, Symptoms, Treatments Nursing Points General Normal value range 19-60 mcg/dL Pathophysiology Byproduct of protein metabolism Proteins → ammonia Ammonia → urea via the liver Urea excreted to the kidneys If ammonia is not converted to urea Ammonia ↑ in bloodstream Causes hepatic encephalopathy Neurotoxic ↓ Level of consciousness Confusion Altered mental status Refer to Neuro lesson 03.06 Encephalopathies Special considerations Sent in either green or lavender tube Typically sent on ice Discuss with facility lab or unit Elevations in ammonia Liver failure Treatment: Lactulose Ammonia binding agent Given PO or PR Ammonia excreted via stool Hepatic encephalopathy TPN GI hemorrhage Reye’s syndrome Decreased ammonia levels Antibiotics Assessment Assess patient’s cognition and level of consciousness Assess patient’s ability to swallow and protect airway Therapeutic Management Lactulose via rectal tube or PO if patient can tolerate oral medications and follow directions Nursing Concepts Lab Values Gastrointestinal/Liver Metabolism