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T4, Free (Thyroxine)

Test Name:T4, Free (Thyroxine)
Epic Order Code:LAB127
CPT Code:84439  
Specimen(s) Type:Plasma or Serum, 0.5 mL
Acceptable Container(s):Tube tops are light green and gold.
Testing Schedule:24 hrs/day, 7 days/week
Turn Around Time:STAT: 1 hour
 Routine: 2 hours
Collection Information:No special patient preparation is required. Obtain specimen by standard collection procedures.
Transport Information:Deliver to lab immediately. All specimens must be signed into the laboratory.
Reference Clients:If unable to deliver to the lab within 1 hour, centrifuge the specimen and remove plasma/serum from the red cells. Store and transport at 2-8° C. Specimen must be received in the lab within 24 hours.
Causes for Rejection:Improperly labeled, incorrect container, contaminated, insufficient quantity, incorrect/delay in transport.
Reference Range:0 - 4 days:0.66 - 2.71 ng/dL
 4 - 60 days:0.83 - 3.09 ng/dL
 2 mos - 2 yrs:0.48 - 2.34 ng/dL
 2 - 7 yrs:0.85 - 1.75 ng/dL
 7 - 12 yrs:0.90 - 1.67 ng/dL
 12 - 19 yrs:0.93 - 1.60 ng/dL
 > 19 yrs:0.93 - 1.70 ng/dL
Additional Information:Furosemide causes elevated free T4 results at the daily therapeutic dosage level.