Thyroid Cascade THCS
| Method(s) | Chemiluminescent Immunoassay |
|---|---|
| Specimen Required | |
| Collect | One 5 mL gold (SST) top tube. Also acceptable: Lithium heparinized plasma, EDTA plasma |
| Transport | 1 mL serum at 2-8ºC (Min: 0.5 mL). |
| Remarks | Samples should not be collected from patients post-angiography with fluorescein as TSH results may be falsely decreased due to assay interference. Retention of fluorescein may persist for several days or longer depending on patient's renal function. |
| Stability | Ambient: 8 hours (FT4); Refrigerated: 2 days; Frozen: 14 days (TSH) |
| Schedule | Daily |
| Billing Code | 1010102 |
| CPTCode | 84443 (If reflexed, 84439 and 84481) |
| Notes | Laboratory Alliance offers a Thyroid Cascade which offers benefits to both providers and patients. The cascade begins with TSH and if abnormal, reflexively orders Free T4. If the Free T4 is normal, the cascade reflexively orders Free T3. For the provider, an order placed for Thyroid Cascade simplifies the mechanism to order the correct first test and the subsequent additional tests required for follow up of patients with abnormal TSH. For the patient, up to three sequential tests can be performed from a single phlebotomy without the need for return visits or additional blood to be drawn for follow-up testing. |
| Preferred Specimen Collection Device(s) | |
