| 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 # |
Thyroxine, Total
Test CodeT4
Alias/See Also
Total T4, T4, Thyroxine
CPT Codes
84436
Preferred Specimen
Plasma Light GREEN (PST)
Other Acceptable Specimens
Serum (Red) or Gold (SST) or Orange (OJ) or Tiger Top Serum
Instructions
Slight hemolysis acceptable.
Specimen Stability
- For plasma, collect blood samples in PST/Green top collection tubes. Allow tubes to mix thoroughly before centrifugation. For serum, collect blood samples in Gold or Red top collection tubes. Allow tubes to clot adequately before centrifugation. Keep tubes stoppered and upright at all times.Samples may be assayed if they are stored at room temperature for up to 8 hours.
- If samples cannot be assayed within 8 hours, refrigerate at 2 – 80C.
- Freeze samples at or below -200C. if the sample cannot be assayed within 48 hours. Thaw samples only once.
Setup Schedule
24x7
Reference Range
6.0-12.2 ug/dL
Interpretations:
Results from patient samples with diagnosed disease states gave:
Interpretations:
Results from patient samples with diagnosed disease states gave:
| Category | T4 (ug/dl) |
| Hypothyroid | 0.0 – 5.5 |
| Hyperthyroid | 10.8 – 19.1 |
| Pregnant Euthyroid | 6.4 – 10.7 |
| Sick Euthyroid | 1.9 – 13.3 |
Clinical Significance
T4 and T3 regulate normal growth and development. They maintain body temperature, stimulate calorigenesis and affect all aspects of carbohydrate metabolism as well as certain areas of lipid and vitamin metabolism. Fetal and neonatal development also require thyroid hormones.
Thyroxine is commonly measured in human serum as total T4, measuring both bound and free T4.
It is used as a thyroid screening test alone or in conjunction with other thyroid tests. Measurement of total T4 gives a reliable reflection of clinical thyroid status in the absence of binding abnormalities.
Thyroxine is commonly measured in human serum as total T4, measuring both bound and free T4.
It is used as a thyroid screening test alone or in conjunction with other thyroid tests. Measurement of total T4 gives a reliable reflection of clinical thyroid status in the absence of binding abnormalities.
Performing Laboratory
CRMC Laboratory
CCMC Laboratory
