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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
T4 Free, Direct Dialysis and T4, Total
Test Code36725
CPT Codes
84436, 84439
Preferred Specimen
2 mL serum
Patient Preparation
Fasting preferred
Minimum Volume
1 mL
Instructions
Please specify on the request form the patients age.
Transport Temperature
Room temperature
Specimen Stability
Room temperature: 4 days
Refrigerated: 7 days
Frozen: 28 days
Refrigerated: 7 days
Frozen: 28 days
Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Lipemia • Heparin plasma • EDTA plasma
Methodology
Equilibrium Dialysis • Chromatography/Mass Spectrometry • Chemiluminescence (CL)
Setup Schedule
Set up: Mon-Sat; Report available: 3-4 days
Reference Range
T4, Free Direct Dialysis
T4, Total
Adult | 0.9-2.2 ng/dL |
Prematures, 25-30 Weeks | |
Birth-7 Days | 0.5-3.3 ng/dL |
Prematures, 31-36 Weeks | |
Birth-7 Days | 1.3-4.7 ng/dL |
Cord Blood, >37 Weeks | 1.2-2.2 ng/dL |
Birth-4 Days | 2.2-5.3 ng/dL |
2 Months-2 Years | 1.2-2.5 ng/dL |
3 Years-17 Years | 1.0-2.4 ng/dL |
Pregnancy | |
First Trimester | 0.9-2.0 ng/dL |
Second Trimester | 0.8-1.5 ng/dL |
Third Trimester | 0.8-1.7 ng/dL |
T4, Total
<1 Month | Not established |
1-23 Months | 6.0-13.2 mcg/dL |
2-12 Years | 5.5-12.1 mcg/dL |
13-20 Years | 5.5-11.1 mcg/dL |
>20 Years | 4.8-10.4 mcg/dL |
Pregnancy | |
First Trimester | 6.4-15.2 mcg/dL |
Second Trimester | 7.4-15.2 mcg/dL |
Third Trimester | 7.7-13.8 mcg/dL |
All TrimestersTogether | 7.0-14.7 mcg/dL |
Clinical Significance
For the differential diagnosis of euthyroid hyperthyroxinemia from hyperthyroidism or for the differential diagnosis of euthyroid hypothyroxinemia from hypothyroidism.