| Thrombin Time Test Posted: 10 Sep 2010 08:39 PM PDT 
The plasma thrombin time test measures how quickly a clot forms when a standard amount of bovine thrombin is added to a platelet poor plasma sample from the patient and to a normal plasma control sample. After thrombin is added, the clotting time for each sample is compared with the other and recorded. Because thrombin rapidly converts fibrinogen to a fibrin clot, the test (also known as the thrombin clotting time test) allows a quick but imprecise estimation of plasma fibrinogen levels, which are a function of clotting time. Purpose of Thrombin Time Test - To detect a fibrinogen deficiency or defect.
- To help diagnose DIC and hepatic disease.
- To monitor the effectiveness of heparin or thrombolytic agents.
Thrombin Time Test Procedure Patient Preparation - Explain to the patient that the plasma thrombin time test determines whether blood clots normally.
- Notify the laboratory and physician of drugs the patient is taking that may affect test results; it may be necessary to restrict them.
- 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 feel slight discomfort from the tourniquet and the needle puncture.
- Inform the patient that he need not to restrict food and fluids.
Implementation - Perform a venipuncture and collect the sample in a 3 to 4.5 ml siliconized tube.
- Completely fill the collection tube and invert it gently several times to mix the sample and the anticoagulant thoroughly. If the tube isn't filled to the correct volume, an excess of citrate appears in the sample.
- To prevent hemolysis, avoid excessive probing during venipuncture and rough handling of the sample.
- Immediately put the sample on ice and send it to the laboratory.
Nursing Interventions - Apply pressure to the venipuncture site until bleeding has stopped.
- If a hematoma develops at the venipuncture site, apply direct pressure. If the hematoma is large, monitor pulses distal to the phlebotomy site.
- Tell the patient that he may resume any medication that was discontinued before the test is ordered.
Interpretation Normal Results - Adults, 140,000 to 400,000/?l (SI, 140 to 400 x 10°/L).
- Children, 150,000 to 450,000//?l (SI, 150 to 450 x 10°/L).
Abnormal Results Prolonged Plasma Thrombin Time - Heparin therapy
- Hepatic disease
- Disseminated intravascular coagulation (DIC)
- Hypofibrinogenemia
- Dysfibrinogenemia
- Acute leukemia
- Lymphoma
- Factor deficiency
- Shock
Interfering Factors - Fibrin degradation products, fibrinogen, streptokinase, urokinase, tissue plasminogen activator (TPA), or heparin (possible increase).
Precautions - To prevent hemolysis, avoid excessive probing during venipuncture and rough handling of the sample.
Complications - Hematoma at the venipunture site.
Related posts: - Serum Creatinine
- Fasting Plasma Glucose
- Alpha-fetoprotein Blood Test
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| Papanicolaou Test (Pap Smear) Posted: 10 Sep 2010 08:29 PM PDT 
 The Papanicolaou test (Pap smear) is a widely known cystologic test for early detection of cervical cancer. The can also be used to detect cancerous cells of the breast, lung, stomach, and renal system. A physician or specifically trained nurse scrapes secretions from the patient's cervic and spreads them on a slide, which is sent to the laboratory for cystologic analysis.
An alternative method is to use the ThinPrep preservative solution rather than a slide. The ThinPrep was introduced in 1996 and allows testing for malignancy cells from the cervix and shows the cell maturity, metabolic activity, and morphology variations. The American Cancer Society recommends a Pap test every 3 years for women between ages 20 and 40 who aren't in a high-risk category and who have had negative results from three previous Pap tests. Yearly tests (or tests at physician-recommended intervals) are advised for women older than age 40, for those in a high risk category, and for those who had a positive test previously. If a Pap test is positive or suggest malignancy, cervical biopsy can confirm the diagnosis. Purpose of Pap Smear - To detect malignant cells.
- To detect inflammatory changes in tissue.
- To assess response to chemotherapy and radiation therapy.
- To detect viral, fungal, and occasionally, parasitic invasions.
Pap Smear Procedure Patient Preparation - Instruct the patient to avoid intercourse for 24 hours, douching for 48 hours, and vaginal creams or medication for 1 week.
- Just before the test, instruct the patient to empty her bladder.
- During the procedure, she might experience a slight discomfort but no pain from the speculum; however, she may feel some pain when the cervix is scraped.
- Explain the procedure takes only 5 to 10 minutes to perform.
- Instruct the patient to disrobe from the waist down and to drape herself.
- Ask her to lie on the examining table and to place her heels in the stirrups.
- Tell her to slide her buttocks to the edge of the table.
Implementation - The patient is assisted into the lithotomy position with her feet in the stirrups.
- An unlubricated speculum is inserted into the vagina.
- The cervix is located.
- Secretions from the cervix and material from the endocervical canal are collected with an endocervical brush and wooden spatula.
- Specimens are spread on slides and immediately immersed in fixative or sprayed with a fixative.
- Specimens are appropriately labeled with date of last menses, collection site, and method.
- If vaginal or vulval lesions are present, scrapings taken directly from the lesion are preferred.
- The slides are preserved immediately.
Nursing Interventions - Help the patient up and ask her to dress when the examination is completed.
- Supply the patient with a sanitary napkin if cervical bleeding occurs.
- Tell the patient when to return for her next Pap test.
Interpretation Normal Results - No malignant cells or abnormalities are present.
Abnormal Results - Cells with relatively large nuclei, only small amounts of cytoplasm, abnormal nuclear chromatin patterns, and marked variation in size, shape, and staining properties, with prominent nucleoli, suggest malignancy.
- Atypical but nonmalignant cells suggest a benign abnormality.
- Atypical cells may suggest dysplasia.
Interfering Factors - Douching within 24 hours of testing.
- Excessive use of lubricating jelly on the slide.
- Collection of specimen during menstruation
- Delay in fixing the specimens
- Consistency of specimen too thin or too thick.
Precautions - Preserve the slides immediately after the specimen is collected.
- Preserve the ThinPrep solution by immediately placing the lid back on the container, as exposure to air or light can cause distortion of cells.
Complications Related posts: - Fecal Occult Blood Test
- Human Chorionic Gonadotropin (hCG) Pregnancy Test
- Breast Biopsy Procedure
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| Rhesus Typing Posted: 10 Sep 2010 08:20 PM PDT 
 The Rhesus (Rh) system classifies blood by the presence or absence of the Rh (D) antigen on the surface of RBC's. In this test, a patient's RBCs are mixed with serum containing anti-Rh (D) antibodies and are observed for clumping. If clumping occurs, the Rh (D) antigen is present, and the patient's blood is typed Rh positive; if clumping doesn't occur, the antigen is absent, and the patient's blood is typed Rh-negative.
Purpose of Rhesus Typing - To establish blood type according to the Rh system.
- To help determine the donor's compatibility before transfusion.
- To determine if the patient will require an Rh (D) immune globulin injection.
Rhesus Typing Procedure Patient Preparation - Confirm the patient's identity using two patient identifiers according to facility policy.
- Explain to the patient that Rh typing determines or verifies blood group to ensure safe blood transfusions.
- Inform the patient that he doesn't need to restrict food and fluids for the test.
- Tell the patient that the test requires a blood sample. Explain that he may experience slight discomfort from the tourniquet and needle puncture.
- Check the patient's history for recent administration of dextran, IV contrast media, or drugs that may alter test results.
Implementation - Perform a venipuncture and collect the sample in a 7-mL EDTA tube.
- Label the sample with the patient's name, the hospital or blood bank number, the date, and your initial.
- If a transfusion is ordered, make sure a transfusion request form accompanies the sample to the laboratory.
Nursing Interventions - Apply direct pressure to the veniouncture site until bleeding stops.
- If a hematoma develops at the venipuncture site, apply direct pressure.
- If necessary, give the pregnant patient a card identifying that she may need to receive Rh (D) injection.
Interpretation Normal Results - If the D antigen is present, that person is Rh positive.
- If the D antigen is absent, that person is Rh-negative.
- Antibodies to Rh antigens develop only as an immune response after a transfusion or during pregnancy.
Abnormal Results - Rh incompatibility is the most common and severe cause of HDN, possible when Rh-negative woman and an Rh-positive man produce an Rh positive baby.
Interfering Factors Precautions - Handle the sample gently and send it to the laboratory immediately.
Related posts: - Thrombin Time Test
- Serum Creatinine
- Fasting Plasma Glucose
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