Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
Paracetamol is a commonly used analgesic which, if taken in excessive amounts, can lead to toxic liver damage and renal impairment.
Specimen container paediatric:
Serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
0.5 mL blood
Minimum volume adult:
1 mL blood
Special requirements:
Sample to be collected at least four hours post ingestion of the paracetamol.
Sample stability:
Unseparated sample: unknown
Separated sample: unknown at 15-25°C,
2 days at 2-4°C,
4 weeks at -20°C
Reference ranges:
Therapeutically the range varies but has been reported to be 10 – 30 mg/L.
High concentrations of paracetamol metabolites or treatment with N-Acetylcysteine (NAC) may result in falsely DECREASED results for creatinine, lactate, triglyceride, cholesterol, HDL-cholesterol and uric acid.
Factors affecting result:
Haemolysis, and some drugs interfere.
N-acetylcysteine interferes to an unpredictable extent, to give lower concentrations than the true value. Interferences of 10 -20% are typical levels, but can be very much higher.
Other info:
Lithium heparin plasma sample also acceptable