Biochemistry Test

Test : Ammonia


Indications : An ammonia test is done for the following reasons (1^✔ ✔Trusted Source
Ammonia blood test

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• To assess liver function when symptoms such as confusion, behavioral changes, excessive sleepiness, coma, or hand tremor are present
• To evaluate the impact of treatment for liver diseases
• To track the prognosis of acute liver failure
• To check ammonia levels in a person receiving nutrition intravenously
• To diagnose Reye syndrome in a newborn. Reye syndrome is a childhood condition that damages the liver and brain.

A blood sample is taken intravenously to carry out the test. Do not smoke, eat or drink anything (other than water) for 8 hours prior to doing the ammonia test. Also, avoid heavy exercise before the test.

Although some doctors believe that arterial blood can also be used for the test, there is no wide-spread consensus on this (2^✔ ✔Trusted Source
Ammonia Test

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A healthcare provider may write for an ammonia test, if your newborn has the below symptoms in the first few days after birth (3^✔ ✔Trusted Source
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• Irritability
• Vomiting
• Lethargy
• Seizures

Physiology : Ammonia is produced when the protein in our diet is broken down in the intestines. This process takes place with the help of digestion-aiding bacteria. Normally, the produced ammonia is converted into urea in the liver, which is then eliminated from the body through urine.

However, this process is impaired in those with liver conditions such as severe hepatitis and cirrhosis, causing the ammonia levels to rise. Ammonia tests are carried out to evaluate the levels of ammonia in the blood (4^✔ ✔Trusted Source
Ammonia blood test

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Normal Range : The normal range is 15 to 45 µ/dL (11 to 32 µmol/L).

Normal value ranges may vary slightly among different laboratories by using different measurements and samples. Consult your specialist for the specific test results (4^✔ ✔Trusted Source
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Interpretation : If the levels of ammonia are higher than normal, it indicates that ammonia is not metabolized and eliminated effectively. Causes include – (4^✔ ✔Trusted Source
Ammonia blood test

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• Reye’s syndrome (usually diagnosed in children)
• Liver /kidney damage (children and adults)
• Enzymatic defect in urea cycle
• Hepatic encephalopathy
• Gastrointestinal bleeding
• Muscle exertion
• Use of certain medications and drugs including diuretics, barbiturates, valproic acid, and narcotics
• Smoking and alcohol consumption
• High body temperature (Hyperthermia)
• Low blood potassium levels

If the levels of ammonia are lower than normal, it indicates the following –

• Certain types of hypertension
• Usage of certain antibiotics such as neomycin

References:

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