Definiton
Serum triglyceride testing provides quantitative analysis of triglycerides, the main storage form of lipids, which constitute about 95% of fatty tissue. Although not in itself diagnostic, serum triglyceride analysis permits early identification of hyperlipidemia (characteristic in nephrotic syndrome and other conditions) and determination of the risk of coronary artery disease (CAD).
Purpose
- To screen for hyperlipidemia or pancreatitis.
- To help identify nephrotic syndrome and poorly controlled diabetes mellitus.
- To assess coronary artery disease (CAD) risk
- To calculate the lower-density lipoprotein cholesterol level using the Friedewald equation.
Procedure
Preparation
- Explain to the patient that the triglyceride test is used to detect fat metabolism disorders.
- Tell the patient that the test requires a blood sample.
- Explain who will perform the venipuncture and when.
- Notify the laboratory and physician of drugs the patient is taking that may affect the test results; it may be necessary to restrict them.
- Instruct the patient to fast at least 12 hours before the test and abstain from alcohol for 24 hours. Tell him that he may drink water.
- Explain to the patient that he may experience slight discomfort from the tourniquet and the needle puncture.
Implementation
- Perform a venipuncture and collect the sample in a 4-ml ethylenediaminetetraecetic acid tube.
- Send the sample to the laboratory immediately.
- Avoid prolonged venous occlusion; remove the tourniquet within 1 minute of application.
Nursing Interventions
- Apply direct pressure to the venipuncture site until bleeding stops.
- If a hematoma develops at the venipuncture site, continue direct pressure.
- Tell that patient that he may resume his usual diet and medication that was discontinued before the test, as ordered.
Interpretation
Normal Results
- Varying levels, depending on age and sex
- In men, 44 to 180 mg/dl (SI, 0.44 to 2.01 mmol/L)
- In women, 10 to 190 mg/dl (SI, 0.11 to 2.21 mmol/L)
Abnormal Results
- An increased or decreased serum triglycerides level is abnormal; additional tests are required for a definitive diagnosis.
- A mild to moderate increase in serum triglyceride levels indicates biliary obstruction, diabetes mellitus, nephrotic syndrome, or over consumption of alcohol.
- Markedly increased levels without an identifiable cause reflect congenital hyperlipoproteinemia and necessitate lipoprotein phenotyping to confirm the diagnosis.
- Decresed serum triglyceride levels are rare and occur mainly in malnutrition and abetalipoproteinemia.
Interfering Factors
- Failure to observe pretest restrictions
- Use of glycol-lubricated collection tube
- Failure to send the sample to the laboratory immediately.
- Antilipenics (decresed serum levels)
- Cholestyramine and colestipol (decreased cholesterol levels but increased or unaffected triglycerides.
- Corticosteroids (long time use)
- Clofibrate ( decreased cholesterol and triglycerides levels)
- Probucol ( decresed cholesterol levels but variable effect on triglycerides levels).
Precautions
- Avoid prolonged venous occlusion; remove the tourniquet within 1 minute of application.
