Hematocrit (HCT)
CPT Code(s):
85014
Turnaround Time:
4 hours
Specimen Requirements
Preferred Specimen:
Whole Blood
Minimum Volume:
1.0 mL
Transport Container:
Lavender Top Tube (EDTA)
Transport Temperature:
Room Temperature
Collection Instructions:
Whole blood collected in lavender EDTA tube; inverted several times to mix blood with anticoagulant.
Rejection Criteria:
Hemolysis; clotted specimen; specimen drawn in any anticoagulant other than EDTA; specimen diluted or contaminated with IV fluid; tube not filled with minimum volume; improper labeling; transfer tubes with whole blood; specimen received with plasma removed (plasma is used for other testing)
Stability Criteria
Room Temperature:
24 hours
Refrigerated:
48 hours
Frozen:
Unacceptable
Clinical Significance
Hematocrit holds specific clinical significance and diagnostic use in evaluating the proportion of red blood cells (RBCs) in the blood. It provides valuable information about the patient's blood volume, oxygen-carrying capacity, and overall health status.
The specific clinical significance and diagnostic use of Hematocrit include:
1. Anemia Assessment: Hematocrit is commonly used to evaluate the presence and severity of anemia. Anemia is characterized by a decrease in the number of RBCs or a decrease in the amount of hemoglobin, resulting in reduced oxygen-carrying capacity. Low hematocrit values indicate anemia, which may be caused by various factors such as iron deficiency, vitamin deficiencies, chronic diseases, or genetic disorders. The test helps healthcare providers identify the underlying cause of anemia and guide appropriate treatment.
2. Polycythemia Evaluation: Conversely, high hematocrit values may indicate polycythemia, a condition characterized by an excessive increase in RBCs. Polycythemia can occur due to various factors such as dehydration, chronic hypoxia, smoking, bone marrow disorders, or certain genetic mutations. Hematocrit helps identify polycythemia and assists in determining the underlying cause for further investigation and management.
3. Blood Loss Assessment: Hematocrit is valuable in assessing the extent of blood loss. Significant blood loss, such as from trauma, surgery, or gastrointestinal bleeding, can lead to a decrease in hematocrit values. Serial measurements of hematocrit levels help healthcare providers monitor blood loss, guide transfusion decisions, and assess the effectiveness of interventions to manage and correct the blood loss.
4. Hydration Status Evaluation: Changes in hydration status can affect hematocrit values. Dehydration can result in increased hematocrit levels due to a relative decrease in plasma volume, while overhydration or fluid retention may lead to decreased hematocrit values. Hematocrit assists in evaluating hydration status and provides important information for managing fluid balance and related conditions.
5. Monitoring Disease Progression and Response to Treatment: In various medical conditions, such as chronic kidney disease, myeloproliferative disorders, and certain cancers, serial hematocrit measurements are performed to monitor disease progression and assess the response to treatment. Changes in hematocrit levels over time provide insights into the effectiveness of therapy and help guide further management decisions.
6. Evaluation of Overall Health Status: Hematocrit is often included as part of a complete blood count (CBC) or basic metabolic panel to assess overall health status. Abnormal hematocrit values can indicate underlying medical conditions or the need for further diagnostic testing. It provides valuable information to healthcare providers for evaluating the patient's overall health and guiding further investigations and treatment plans.
It is important to note that the interpretation of hematocrit values requires considering various factors such as age, sex, altitude, smoking status, and individual patient characteristics. Reference ranges may vary depending on the laboratory and patient population.
In summary, Hematocrit has specific clinical significance in assessing anemia, evaluating polycythemia, assessing blood loss, evaluating hydration status, monitoring disease progression, and providing insights into overall health status. By measuring the proportion of RBCs in the blood, this test assists in diagnosing and managing various medical conditions and optimizing patient care outcomes related to blood-related disorders.