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ID:21 Ammonia
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DescriptionTHE LAB MUST BE ADVISED AT ALL TIMES BEFORE SAMPLING AND SEND TO LAB IMMEDIATELY. Please also note time of sampling. Results on samples more than 30 minutes old are not reliable. It is not possible to add this test to a sample previously sent to the laboratory
IndicationHepatic disorders
Additional InfoBlood ammonia is increased in infants relative to adults because of the continuing development of hepatic circulation after birth. Sick pre-term infants may present with increased ammonia (up to 200 nmol/L) in the absence of any clinical findings. Infection should always be considered as a possible cause. Other more specific causes are as follows: NEONATE: Inherited metabolic disorder (urea cycle defects), transient hyperammonaemia, IV feeding, infection, liver disease. NEONATE TO ADULT: Inherited metabolic disorder, IV feeding, valproate, Reye's syndrome, liver disease. It is important to consider ammonia in the investigation of a child with undiagnosed encepholopathy, a respiratory alkalosis or vomiting in response to protein intake. Reye's Syndrome is an acute, often fatal encephalopathy and fatty degeneration of the liver. It is seen mainly in children (between 2-13 yrs age) and is caused by accumulation of ammonia. Blood ammonia, ALT/AST are all raised and the prothrombin time will be prolonged due to hepatic necrosis and cholestasis.
Concurrent Testsna
Dietary Requirementsna

TubeHeparin Gel
Tube Picture
Collection ConditionsAmmonia will be artefactually elevated by prolonged application of a tourniquet. Ensure that venepuncture site is not contaminated by urine which has very high ammonia concentration.
Min. Vol1 mL

Ref. Range (Male)<50
Ref. Range (Female)<50
Ref. Range (Paed)see below
Ref. Range Notes0 - 4wks: <100, >4wks: <50, prem/sick neonate: <150
IP Acute TATRefer to Website
IP Routine TATRefer to Website
GP Acute TAT- Contact Laboratory
GP Routine TATRefer to Website
Turnround CommentNA

Originally edited by : JHB. Review due on 18/01/2019 13:04:11. Published By Sylvia Bennett on 18/01/2018 13:04:11.