Laboratory Medicine
Test Directory / Ammonia
Ammonia
EDTA
| Test | Ammonia |
|---|---|
| Common Abbreviations | AMM |
| Profile | NA |
| Tube type | EDTA |
| Clinical Indication | Advanced liver diseases and hepatic encephalopathy result in raised levels of ammonia in blood. Therefore, plasma ammonia concentrations serve as an indicator of liver cell damage and possible impending hepatic coma. Hyperammonaemia is also common in inherited deficiencies of the enzymes involved in the conversion of ammonia to urea and can be seen with some drugs (e.g. valproate) |
| Specimen Type | Blood |
| Sample type | EDTA plasma |
| Minimum Volume | 1mL |
| Special Precautions | Sample must be sent to the laboratory on ice ASAP after collection. |
| Stability | Samples received after 30 minutes from collection are not suitable for analysis. |
| Turnaround Time | Inpatient: 12 hours Outpatient/ GP: 12 hours |
| Laboratory | York |
| Reference Interval | Neonates (<4 weeks): 10-100 umol/L Adults: 10-47 umol/L |
| Limitations | Haemolysis and delayed seperation may lead to falsely raised results. Contamination from environmental sources of ammonia, including blood bottles, is possible. Sulfasalazine / Sulfapyridine (300mg/L, therapeutic dose) may result in undetectable ammonia values; Temozolomide may cause erroneous results; Cefoxitin may cause falsely high results; Intralipid causes falsely low results. |
| Notes |
