Ammonia is a colorless, pungent-smelling gas composed of one nitrogen and three hydrogen atoms (NH3). The main site of formation in the human body is the intestine, particularly the colon (large intestine). Here, bacterial processes release and reabsorb ammonia from undigested protein.
The breakdown takes place mainly in the liver. This explains why protein meals lead to so-called ammonia intoxication (ammonia poisoning) in the case of liver damage. This leads to a toxic effect of ammonia on the central nervous system (CNS) and with the consequence of disorientation and cerebral convulsions. Ammonia is thus a parameter of the detoxification capacity of the liver.
Ammonia has an important function as an intermediate in the breakdown and degradation of amino acids. Due to the toxicity (toxicity) of larger amounts of ammonia, it is converted to the nontoxic urea for excretion in the body.
The process
Material needed
- EDTA plasma (centrifuged at +4°C within 30 minutes after blood collection; frozen: approx. -20°C).
Preparation of the patient
- Not required
Disruptive factors
- Rapid transport of the frozen sample to the laboratory.
- Attention. Shelf life max. 2 hours at +2 °C – +8 °C.
Standard values – blood serum
| Ms. | 25-94 |
| Man | 19-82 |
Indications
- Liver dysfunction
- Differential diagnosis in unclear coma.
Interpretation
Interpretation of increased values
- Premature births, low birth weight
- Urinary tract infections associated with abnormalities of the urinary tract
- High-dose chemotherapy
- Hyperammonemia (abnormally elevated blood ammonium levels), congenital
- Hypokalemia (potassium deficiency) → increase in ammonia production in the kidney.
- Infections
- Hepatic coma
- Liver parenchymal damage leading to impaired liver function
- Liver cirrhosis – connective tissue remodeling of the liver leading to functional impairment.
- Plasmocytoma (multiple myeloma) – malignant (malignant) systemic disease.
- Reye syndrome – acute loss of consciousness combined with steatohepatitis (fatty liver hepatitis), which may occur in children after a viral infection; an association with acetylsalicylic acid (ASA) use has been described
- Medications
- Diuretic overdose (diuretic: drug used to flush out water).
- High-dose chemotherapy
- Valproic acid
Interpretation of lowered values
- Not relevant to the disease
Further notes
- There is a low correlation between the level of ammonia concentration and the degree of hepatic encephalopathy (potentially reversible brain dysfunction resulting from inadequate liver detoxification function).