TRH Stimulation Profile

Message

Refer to TRH(TSH) Stimulation test located on WTH Intranet for test instructions or instructions below.

Test Code

TRH

CPT Codes
80438

Includes

TSH

Preferred Specimen

Serum (gold top tube) - 1.0 mL

Minimum Volume

0.5 mL

Other Acceptable Specimens

Lithium Heparin Plasma (green top tube)

Instructions

TRH: MUST BE SCHEDULED IN NURSING. Draw one red top tube for specific times and label a This procedure is performed by nursing as it involves use of a port and adminstration of Thyrotropin(ordered by physician from pharmacy). Draw one red top tube for specific times and label accordingly. NOTIFY LAB IMMEDIATELY AFTER THYROTROPIN IS ADMINISTERED. Blood for TSH's should be drawn from heplock at 20 minutes, 30 minutes and 60 minutes following injection of Thypinone.

Transport Container

Serum (gold top) or Lithium Heparin Plasma (green top) tube

Transport Temperature

Stable for 7 days refrigerated at 2-8-C

Specimen Stability

Room temperature - 1 day; Refrigerated - 7 days

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Turbidity; IV contamination; Qunatitiy Not Sufficient

Methodology
Chemiluminescence

Setup Schedule

MUST BE SCHEDULED WITH NURSING.

Report Available

Upon of Completion of Analysis

Limitations

Turbidity; IV contamination; Qunatitiy Not Sufficient

Reference Range

0.465 - 4.68 mIU/mL

Clinical Significance

TSH secretion by the anterior pituitary is controlled by thyrotropin releasing hormone, a tripeptide produced by the hypothalmus. TSH simulates the production of thyroxine(T4) and triidothyronine(T3) by the thyroid gland. The circulating free fractions of T4 and T3 in turn regulate the secretion of TSH by a negative feedback mechanism at the pituitary and the hypothalmus. The diagnosis of overt hypothyroidism by the finding of a low T4 or FT4 concentration is readily confirmedby a raised TSH concentration. Measurement of low or undetectable TSH concentrations may assist the diagnosis of hyperthyroidism where concentrations of T4 and T3 are elevated and TSH secretion is suppressed.

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.