Test Code TSHFT4 Thyroid-Stimulating Hormone- Sensitive (s-TSH) with T4 (Thyroxine),Free Reflex if indicated, Serum or Plasma
Additional Codes
Testing Algorithm
| Age | TSH (u[IU]/mL | Reflexed FT4 |
| 0-1 month | <0.72 | Performed |
| 0-1 month | >13.10 | Performed |
| 2 months - 4 years | <0.46 | Performed |
| 2 months - 4 years | >8.10 | Performed |
| 5 years - 17 years | <0.36 | Performed |
| 5 years - 17 years | >5.80 | Performed |
| 18 years and older | <0.27 | Performed |
| 18 years and older | >4.20 | Performed |
Methodology
Electrochemiluminescence Immunoassay (ECLIA)
Specimen Requirements
Container/Tube:
Preferred: Lithium heparin (light green-top)
Acceptable: Serum Gel
Draw blood, spin down and send 1 mL (pediatric: 0.2 mL) of plasma or serum.
Reject Due To
|
Hemolysis |
Mild: |
ok |
Gross: |
ok |
|
Lipemia |
Mild: |
ok |
Gross: |
ok |
|
Icterus |
Mild: |
ok |
Gross: |
Reject |
Reference Values
See individual components. TSH and FT4
Day(s) Test Set Up
Monday through Sunday
CPT Coding
84443- TSH
84439- T4, free (if appropriate)
Performing Laboratory
Huntsville Hospital Laboratory/Madison Hospital Laboratory
Specimen Stability Information
|
Specimen Type |
Temperature |
Time |
|
Plasma,lithium heparin / Serum |
RT, spun |
8 days |
| Refrigerated, spun | 14 days |
Secondary ID
HHA253
LOINC Coding
| Test Name | LOINC Code |
|---|---|
|
Thyroid-Stimulating Hormone - Sensitive (s-TSH), Serum or Plasma |
3016-3 |
| T4 (Thyroxine), Free, Serum or Plasma | 3024-*7 |