Test Code THYROID FUNCTION CASCADE THYROID FUNCTION CASCADE
Department
Chemistry
Specimen Type
Plasma or serum
Method
Immunoenzymatic Assay
Container
Lithium heparin (green-top) or No additive with gel (gold top)
Standard Volume
3ml
Minimum Volume
3ml
Pediatric Volume
1.5ml
Ship Temperature
Room Temperature
Stability Refrigerated
48 hours
Stability Room Temp
8 hours
Stability Frozen
5 days
CPT Code
84443
Days Test Set Up
Monday through Sunday
Group Components
TSH
Free T4 if TSH is <0.45 or Free T4 and TPO if TSH is >5.33
Total T3 if the Free T4 is normal with a TSH <0.10
Reflexive Disclosure
Initial TSH test will be run.
If TSH is <0.45 a Free T4 will be run; or
If TSH is <0.10 a Free T4 will be run; if normal a Total T3 will be run
If TSH is >5.33 a Free T4 and TPO will be run. Additional CPT codes if appropriated: 84439(if appropriate), 84480(if appropriate), 86376 (if appropriate)