Hemoglobin (Hb), Free, Plasma
Also known as: Free Hemoglobin, Hb Solubility, Hemoglobin, Free, Plasma Free Hemoglobin
Use
Evaluate hemolytic anemia, especially intravascular hemolysis. Plasma hemoglobin is increased with intravascular hemolysis, ABO incompatible transfusion, traumatic hemolysis, falciparum malaria, burns, and march hemoglobinuria. Increase may occur in some cases of extravascular hemolysis, delayed transfusion reaction, slight increase in sickle cell anemia, and β-thalassemia.
Special Instructions
Patient should not exercise just prior to the test. It is recommended to follow specific procedures to collect the sample without inducing hemolysis, involving careful technique and specific equipment like an 18-gauge needle with infusion tubing.
Limitations
High bilirubin levels (>20 mg/dL), turbidity, methemalbuminemia, lipemic plasma, or hemolysis during/after venipuncture may cause falsely elevated values in the plasma hemoglobin test. Performance characteristics are determined by LabCorp, and results are labeled for research purposes only by the assay's manufacturer. Not for treatment or diagnostic use without further confirmation by another diagnostic procedure.
Methodology
Other
Biomarkers
LOINC Codes
- 721-1
- 721-1
Result Turnaround Time
3-4 days
Related Documents
For more information, please review the documents below
Specimen
Plasma
Volume
1 mL
Minimum Volume
0.1 mL
Container
Green-top (heparin) tube
Collection Instructions
Recommended procedure for collecting sample without inducing hemolysis: use an 18-gauge needle with attached infusion tubing. Place the tourniquet lightly around the upper arm. Puncture an antecubital vein with minimal trauma. Release the tourniquet and clamp the tubing off as soon as blood return is seen. First collect 3 mL blood in a red-top tube with the lid off. Then, collect 5 mL in an anticoagulated tube with the cap off. Mix the anticoagulant tube gently three to five times after collection and centrifuge immediately to separate plasma and transfer to a transfer tube.
Patient Preparation
Patient should not exercise just prior to the test.
Storage Instructions
Refrigerate at 2°C to 8°C or freeze at -20°C for up to six days.
Causes for Rejection
Traumatic venipuncture causing hemolysis; very icteric or lipemic specimen; specimen not heparinized plasma
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 6 days |
| Refrigerated | 6 days |
| Frozen | 6 days |