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HelpTest Code LAB4203 TSH, TRH STIMULATION
Specimen Type
Preferred Specimen: Lithium Heparin Plasma (Mint Green Top, Dark Green Top)
Alternative Specimen: Serum (SST, Gold, Corvac, Tiger, Red Top Tube)
Collection Instructions
Take vital signs. Insert heparin lock. Draw baseline TSH. Have patient empty bladder. With patient in supine position inject 500 mcg of TRH IV as a bolus over a period of 15-30 seconds. Monitor blood pressure frequently over the first 15 minutes or until a clear trend downward is seen. Draw TSH levels at 30 and 60 minutes after injection is complete.
Specimen Volume
1 mL
Minimum Volume
0.5 mL for each specimen
Turnaround Time
STAT: 1 hour
Routine: 4 hours
Times are after all specimens are received
Test Schedule
Must be scheduled with SSU, TSH is performed every day
Sample Stability
Room Temp: 8 days
Refrigerated: 14 days
Frozen: 24 months
Specimen Processing
Clearly label each specimen.
Method
ECL
Reference Ranges
Baseline TSH µIU/mL
0 Days to 3 Days: 5.17 - 14.60
4 Days to 31 Days: 0.43 - 16.10
1 Month to 1 Years: 0.62 - 8.05
2 Years to 6 Years: 0.54 - 4.53
7 Years to 11 Years: 0.53 - 3.59
12 Years to 17 Years: 0.53 - 3.59
Adult: 0.27 - 4.20
Post TRH TSH: The minimum normal response is an increase (30 minute) of 1-2 µIU/mL above baseline. The typical response is an increase of 5 to 10 fold above baseline. µIU/mL Post TRH TSH µIU/mL (60 minute)
Test Components
Baseline TSH, µIU/mL
Post TRH TSH (30 minutes), µIU/mL
Post TRH TSH (60 minutes), µIU/mL.
CPT Codes
84443 × 3