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:
Monitoring serum lithium concentrations is an important part of treatment in patients with acute mania. However, accurate prediction of dosage is difficult as the drug’s toxic/therapeutic ratio is very low and it’s pharmacokinetics vary from person to person.
Lithium is used for prophylaxis in patients with recurrent unipolar and bipolar affective illnesses. However, in such patients it may be difficult to find a dosage that is effective and does not cause adverse effects.
Because serum lithium concentrations vary quite widely between doses it is important that they are measured at a standard time. This measurement is called the standard serum lithium concentration, and has been standardised at twelve hours after the previous dose.
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:
Do not use lithium heparin tubes.
Standard sampling time of 12h post dose is recommended.
Sample stability:
Before separation: day of collectionAfter separationat +15° to +25°C: 1 day
at +2° to +8°C: 7 days
at -20°C: 6 months
Reference ranges:
Therapeutic range: 0.4 – 1.0 mmol/L