| Fecal Occult Blood Test Posted: 08 Sep 2010 09:44 PM PDT 
 Fecal occult blood test is also known as stool occult blood test, hemoccult test, guiaic smear test, gFOBT, or occult blood test. Fecal occult blood is detected by microscopic analysis or by chemical tests for hemoglobin, such as the guiaic test. Normally, stools contain small amounts of blood (2-2.5 mL/day); therefore, test for occult blood detect quantities larger than this. Testing is indicated when clinical symptoms and preliminary blood studies suggest GI bleeding. Additional tests are required to pinpoint the origin of the bleeding.
Purpose - To detect gastro intestinal bleeding.
- To aid in the early diagnosis of colorectal cancer.
Procedure Preparation - Explain the patient that this test detects abnormal GI bleeding.
- Instruct the patient to maintain a high-fiber diet and to refrain from eating red meats, turnips, and horseradish for 48 to 72 hours before the test as well as throughout the collection period.
- Tell the patient that the test usually requires three fecal specimens but that sometimes only one sample is needed.
- Instruct the patient to avoid contaminating the fecal specimen with toilet tissue or urine.
- Notify the laboratory and physician of drugs the patient is taking that may affect test results; it may be necessary to restrict them. If the patient must continue using this drugs, note this on the laboratory request.
Implementation - Collect three fecal specimens or a random fecal specimen.
- Obtain specimens from two different areas of each fecal specimen.
Hematest - Use a wooden applicator to smear a bit of the fecal specimen on the filter paper supplied with the kit. Or, after performing a digital rectal examination, wipe the finger you used for the examination on a square of the filter paper. Place the filter paper with the fecal smear on a glass plate.
- Remove a reagent tablet from the bottle and immediately replace the cap tightly. Place the tablet in the center of the fecal smear on the filter paper. Add 1 drop of water to the tablet, and allow it to soak in for 5 to 10 seconds. Add a second drop, letting it run from the tablet onto the specimen and filter paper.
- After 2 minutes, the filter paper will turn blue if the test result is positive. Don't read the color that appears on the tablet itself or develops on the filter paper after the 2-minute period. Note the results and discard the filter paper. Remove and discard your gloves and wash your hands thoroughly.
Hematocrit test - Open the flap on the side pack and use a wooden applicator to apply a thin smear of the fecal specimen to the guiaic-impregnated filter paper exposed in a box. Apply a second smear from another part of the specimen to the filter paper exposed in box B.
- Let the specimen dry for 3 to 5 minutes. Open the flap at the near of the slide package and place 2 drops of hematocrit developing solution on the paper over each smear. A positive result yields a blue reaction in 30 to 60 seconds. Record the results and discard the slide package. Remove and discard your gloves and wash your hands thoroughly.
Instant-View Fecal Occult Blood Test - Add a fecal sample to the collection tube. Shake it to mix the sample with the extraction buffer, and then dispose 4 drops into the sample well of the cassette.
- Results will appear on the test region and the control region of the cassette in 5 to 10 minutes, indicating whether the hemoglobin level is > 0.05 pg/ml of feces.
Nursing Interventions - Send the specimen to the laboratory or perform the test immediately, depending on which test is used.
- Inform the patient that he may resume his usual diet and medications as ordered.
- Single digital office-based test may not be as accurate as serial home collected test.
Interpretations Normal Results - Less than 2.5 ml of blood in feces, resulting in a green reaction.
Abnormal Results - GI bleeding, this may result from many disorders, such as varices, a peptic ulcer, carcinoma, ulcerative colitis, dysentery, hemorrhagic disease.
Interfering Factors - Failure to observe pretest reactions.
- Failure to test the specimen immediately or to send it to the laboratory immediately after collection.
- Bromides, colchicines, indomethacin, iron preparation, phenylbutazone, rauwolfia derivatives, and steroids (possible increase from GI blood loss).
- Ascorbic acid (false-negative, even with significant bleeding).
- Ingestion of 2 to 5 ml of blood (for example, from bleeding gums).
- Active bleeding from hemorrhoids (possible false-positive results).
Related posts: - Alpha-fetoprotein Blood Test
- Blood Urea Nitrogen (BUN)
- Arterial Blood Gas Analysis
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| Electromyography Posted: 08 Sep 2010 09:19 PM PDT 
 Electromyography (EMG) is the recording of electrical activity of selected skeletal muscle groups at rest and during voluntary contraction. In this test, a needle electrode is inserted percutaneously into a muscle. The muscle's electrical discharge (or motor unit potential) is then measured and displayed on an oscilloscope screen.
Purpose - To aid in differentiating between primary muscle disorders, such as the muscular dystrophies, and secondary disorders.
- To help assess diseases characterized by central neuronal degeneration such as ALS.
- To help diagnose neuromascular disorders such as myasthenia gravis.
- To help diagnose radiculopathies.
Procedure Preparation - Make sure the patient has signed an appropriate consent form.
- Note and report all allergies.
- Check for and note drugs that may interfere with test results such as cholinergics, anticholinergics, anticoagulants, and skeletal muscle relaxants.
- Tell the patient he need not restrict food and fluids before the test but that it may be necessary to restrict cigarettes, coffee, tea, and cola for 2 to 3 hours beforehand.
- Warn the patient that he might experience some discomfort as a needle is inserted into selected muscles.
- Explain that the test takes at least 1 hour.
Implementation - The patient is positioned in a way that relaxes the muscle to be rested.
- Needle electrodes are quickly inserted into the selected muscle.
- A metal plate lies under the patient to serve as a reference electrode.
- The resulting electrical signal is recorded during rest and contraction, amplified 1 million times, and displayed on an oscilloscope or computer screen.
- Lead wires are usually attached to an audio-amplifier so that voltage fluctuations within the muscle are audible.
Nursing Interventions - Assess the patient's pain level. If the patient experiences residual pain, apply warm compresses and administer prescribed analgesics.
- Tell the patient that he may resume his usual medications as ordered.
- Monitor the patient for signs and symptoms of infection at the needle electrode sites.
Interpretation Normal Results - At rest, muscle exhibits minimal electrical activity.
- During voluntary contraction, electrical activity increased markedly.
- A sustained contraction, or one of increasing strength, produces a rapid "train" of motor unit potentials.
Abnormal Results - Short (low-amplitute) motor unit potentials, with frequent, irregular discharges suggest possible primary muscle disease such as muscular dystrophies.
- Isolated and irregular motor unit potentials with increased amplitude and duration suggest possible disorders such as ALS and peripheral nerve disorders.
- Initially normal motor unit potentials that progressively diminish in amplitude with continuing contractions suggest possible myasthenia gravis.
Interfering Factors - The patient's inability to comply with instructions.
- Drugs affecting myoneural junctions, such as anticholinergics, cholinergics, and skeletal muscle relaxants.
Precaution - EMG is contraindicated in the patient with a blessing disorder.
Complications - Infection at the insertion site.
Related posts: - Bone Marrow Aspiration and Biopsy
- Arthrography
- ADMINISTERING AN INTRADERMAL INJECTION
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| Fasting Plasma Glucose Posted: 08 Sep 2010 09:12 PM PDT 
 The fasting plasma glucose (or fasting blood sugar) test is used to measure plasma glucose levels after a fast of at least 8 hours. This test is commonly used to screen for diabetes mellitus and prediabetes, in which absence of deficiency of insulin allows persistently high glucose levels.
Purpose - To screen for diabetes mellitus and prediabetes.
- To monitor drug or diet therapy in the patient with diabetes mellitus.
- To monitor for hyperglycemia and hypoglycemia.
Fasting Plasma Glucose Procedure Preparation - Explain to the patient that this test detects disorders of glucose metabolism and aids in the diagnosis of diabetes.
- Tell the patient that the test requires a blood sample. Explain who will perform the venipuncture and when.
- Explain to the patient that he may experience slight discomfort from the tourniquet and needle puncture.
- Instruct the patient to fast for 12 to 14 hours before the test.
- Notify the laboratory and physician of medications the patient is taking that may affect test results; it may be necessary to restrict them.
- Alert the patient to the symptoms of hypoglycemia such as weakness, restlessness, nervousness, hunger, and sweating and tell him to report such symptoms immediately.
Implementation - Perform a venipucture and collect the sample in a 5-ml clot-activator tube.
- Send the sample to the laboratory immediately.
- Note on the laboratory results when the patient last ate, when the sample was collected, and when the patient received the last pretest dose of insulin or oral antidiabetic drug (if applicable).
Nursing Interventions - Apply direct pressure to the venipucture site until bleeding stops.
- Provide a balanced meal or a snack.
- Instruct the patient that he may resume his usual medications that were stopped before the test.
Interpretation Normal Results - Results vary according to the laboratory procedure.
- After at least an 8-hour fast, 70 to 100 mg of true glucose per deciliter of blood (SI, 3.9 to 5.6 mmol/L).
Abnormal Results Elevated Levels - Diabetes mellitus (fasting plasma glucose levels of 126 mg/dL {SI, 7 mmol/L} or more obtained on two or more occasions).
- Impaired fasting glucose or impaired glucose tolerance (levels ranging from 110-125 mg/dL).
- Pancreatitis, recent acute illness (such as myocardial infarction), Cushing's syndrome, acromegaly, and pheochromocytoma.
- Acute stress
- Hyperthyroidism
- Pancreatic cancer
- Hyperlipoproteinemia
Interfering Factors - Recent illness, infection,, or pregnancy (possible increase).
- Glycolisis resulting from failure to refrigerate the sample or to send it to the laboratory immediately (possible false negative).
- Acetaminophen, if using the glucose oxidase or hexokinase method (possible false positive).
- Arginine, benzodiazepines, chlorthalidone, corticosteroids, and dextrothyroxine may cause an increase.
- Ethacrynic acid may cause hyperglycemia; large doses in patients with uremia can cause hypoglycemia.
- Alcohol, beta-adrenergic blockers, insulin, monoamine oxidase inhibitors, and oral antidiabetic agents (possible decrease).
- Stenous exercise (decrease)
- Drug interactions: numerous medications may alter blood glucose levels.
Complications - Hematoma at the venipuncture site.
Related posts: - Serum Creatinine
- Nursing Care Plan – Diabetes Mellitus Type 2
- Nursing Care Plan – Diabetes Mellitus Type 1
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