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:
Aspirin is an analgesic, antipyretic, anti-inflammatory drug contained in a large number of preparations. Aspirin is rapidly hydrolyzed by the liver to the pharmacologically active intermediate, salicylate. Salicylate measurement in serum is used to diagnose and treat salicylate overdose and to monitor salicylate levels to ensure appropriate therapy. Salicylate overdosage can cause acid-base disturbances such as compensated respiratory alkalosis, metabolic acidosis with increased anion gap (severe toxicity) and hypokalaemia.
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
Sample stability:
Before separation:
unknown
After separation:
at +15° to +25°C: 7 day
at +2° to +8°C: 14 days
at -20°C: 6 months
Quality assurance:
WEQAS
Interpretation:
Severity of poisoning cannot be assessed from plasma salicylate concentrations alone but salicylate intoxication is usually associated with plasma concentrations greater than 350 mg/L. Measurement of serum salicylate is not intended for use with low-dose aspirin therapy.
Most patients on low daily doses of aspirin for cardiovascular prophylaxis will have serum concentrations near or below the lower limit of the analytical range.
Reference ranges:
Therapeutic Ranges:
Analgesia,
antipyresis: 30 – 100 mg/L
Anti-inflammatory: 150 – 300 mg/L
Other info:
Lithium heparin plasma samples also acceptable