fibrin split products
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Fibrin Split Products
Fibrin split products (FSP) are fragments of protein released from a dissolving clot. The fibrin split products test is one of several tests done to evaluate a person with blood clotting problems (coagulation), particularly disseminated intravascular coagulation (DIC).
High levels of FSP in a person's blood are associated with DIC, a serious medical condition that develops when the normal balance between bleeding and clotting is disturbed. Excessive bleeding and clotting injures body organs, and causes anemia or death.
Coagulation begins typically with an injury to some part of the body. The injury sets in motion a cascade of biochemical activities (the coagulation cascade) to stop the bleeding, by forming a clot from a mixture of the blood protein fibrin and platelets.
Once bleeding is stopped, another blood protein dissolves the clot by breaking down the fibrin into fragments. Measurement of these fragments gives information about the clot dissolving portion of coagulation, called fibrinolysis.
In DIC, the coagulation cascade is triggered in an abnormal way. A blood infection, a transfusion reaction, a large amount of tissue damage, such as a burn, a dead fetus, and some cancers can begin the chain of biochemical events leading to blood clots. The coagulation cascade becomes overwhelmed with excessive clotting followed by excessive bleeding. As the large number of clots dissolve, fibrin split products accumulate in the blood and encourage even more bleeding.
Laboratory tests for FSP are done on the yellow liquid portion left over after blood clots (serum). A person's serum is mixed with a substance that binds to FSP. This bound complex is measured, and the original amount of FSP is determined. Some test methods give an actual measurement of FSP; some give a titer, or dilution. Methods that provide a titer look for the presence or absence of FSP. If the serum is positive for FSP, the serum is diluted, or titered, and the test is done again. These steps are repeated until the serum is so dilute that it no longer gives a positive result. The last dilution that gives a positive result is the titer reported.
The FSP test is covered by insurance when medically necessary. Results are usually available within one to two hours. Other names for this test are fibrin degradation products, fibrin breakdown products, or FDP.
This test requires 0.17 oz (5/14m) of blood. A healthcare worker ties a tourniquet on the patient's upper arm, locates a vein in the inner elbow region, and inserts a needle into that vein. Vacuum action draws the blood through the needle into an attached tube. Collection of the sample takes only a few minutes.
Discomfort or bruising may occur at the puncture site. Pressure applied to the puncture site until the bleeding stops reduces bruising. Warm packs to the puncture site relieve discomfort. The patient may feel dizzy or faint.
People with coagulation problems may bleed longer than normal. The healthcare provider must make sure bleeding has stopped before leaving the patient unattended.
Negative at a less than or equal to 1:4 dilution or less than 10 g/mL.
High levels of FSP indicate DIC. Results of the test must be interpreted by the physician according to the person's clinical symptoms and medical history. Other conditions that increase blood clotting activity also increase FSP: venous thrombosis, surgery and transplants, blood clots in the lung, certain cancers, and heart attack (myocardial infarction).
Miller, Jonathan L. "Blood Coagulation and Fibrinolysis." In Clinical Diagnosis and Management by Laboratory Methods, edited by John B. Henry., 19th ed. Philadelphia: W. B. Saunders Co., 1996.
Hardaway, Robert M., and Charles H. Williams. "Disseminated Intravascular Coagulation: An Update." Comprehensive Therapy November 1996: 737-743.
Coagulation — The entire process of blood clotting.
Coagulation cascade — A sequence of biochemical activities to stop bleeding by forming a clot.
Disseminated intravascular coagulation (DIC) — A serious medical condition that develops when the normal balance between bleeding and clotting is disturbed. Excessive bleeding and clotting injures body organs, and causes anemia or death.
Fibrin split products (FSP) — Pieces of the protein fibrin released from a dissolving clot.
Fibrinolysis — The clot dissolving portion of the coagulation process.
Titer — A dilution of a substance with an exact known amount of fluid. For example, one part of serum diluted with four parts of saline is a titer of 1:4.
fibrin split products
The materials released into the bloodstream when the crosslinked fibrin in a blood clot is digested by plasmin.
Fibrinogen Degradation Products
Synonym/acronym: Fibrin split products, fibrin breakdown products, FDP, FSP, FBP.
To evaluate conditions associated with abnormal fibrinolytic and fibrinogenolytic activity such as disseminated intravascular coagulation (DIC), deep vein thrombophlebitis (DVT), and pulmonary embolism (PE).
SpecimenPlasma (1 mL) collected in a completely filled blue-top (3.2% sodium citrate) tube. If the patient’s hematocrit exceeds 55%, the volume of citrate in the collection tube must be adjusted.
(Method: Latex agglutination)
|Conventional Units||SI Units (Conventional Units × 1)|
|Less than 5 mcg/mL||Less than 5 mg/dL|
This coagulation test evaluates fibrin split products or fibrin/fibrinogen degradation products (FDPs) that interfere with normal coagulation and formation of the hemostatic platelet plug. As thrombin initiates the formation of the fibrin clot, it also activates the fibrinolytic system to limit the size of clot formation and prevent venous occlusion. The d-dimer is specific to secondary fibrinolysis because it detects the disintegration of fibrin rather than fibrinogen. The FDP test detects degradation products of primary fibrinolysis generated by the action of thrombin on fibrinogen as well as degradation products of secondary fibrinolysis by the action of plasmin on fibrin. The two tests together can be useful for differentiation and treatment of suspected cases of fibrinolysis. In the case of primary fibrinolysis, the FDP will be positive while the d—dimer is normal. In DIC, or secondary fibrinolysis, both will be elevated. FDPs are normally cleared rapidly from circulation, however increased circulating levels can interfere with hemostasis by interfering with fibrin polymerization and adhering to platelet cell membranes thereby inhibiting their normal function.
This procedure is contraindicated for
- Assist in the diagnosis of suspected DIC
- Evaluate response to therapy with fibrinolytic drugs
- Monitor the effects on hemostasis of trauma, extensive surgery, obstetric complications, and disorders such as liver or renal disease
- DIC (FDP can be positive in a number of conditions in which the coagulation system has been excessively stimulated as a result of tissue injury and fibrin and/or fibrinogen is being degraded by plasmin)
- Excessive bleeding (clot formation related to depletion of platelets and clotting factors will stimulate fibrinolysis and increase circulation of fibrin breakdown products)
- Liver disease (related to decreased hepatic clearance)
- Myocardial infarction (FDP can be positive in a number of conditions in which the coagulation system has been excessively stimulated as a result of tissue injury and fibrin and/or fibrinogen is being degraded by plasmin)
- Obstetric complications, such as pre-eclampsia, abruptio placentae, intrauterine fetal death (excessive stimulation of the coagulation system; microthrombi are formed and plasminogen is released to dissolve the fibrin clots)
- Post–cardiothoracic surgery period (FDP can be positive in a number of conditions in which the coagulation system has been excessively stimulated as a result of tissue injury and fibrin and/or fibrinogen is being degraded by plasmin)
- Pulmonary embolism (FDP can be positive in a number of conditions in which the coagulation system has been excessively stimulated as a result of tissue injury and fibrin and/or fibrinogen is being degraded by plasmin)
- Renal disease (FDP can be positive in a number of conditions in which the coagulation system has been excessively stimulated as a result of tissue injury and fibrin and/or fibrinogen is being degraded by plasmin)
- Renal transplant rejection
- Traumatic venipunctures and excessive agitation of the sample can alter test results.
- Drugs that may increase fibrin degradation product levels include heparin and fibrinolytic drugs such as streptokinase and urokinase.
- The presence of rheumatoid factor may falsely elevate results with some test kits.
- The test should not be ordered on patients receiving heparin therapy.
- Hematocrit greater than 55% may cause falsely prolonged results because of anticoagulant excess relative to plasma volume.
- Incompletely filled collection tubes, specimens contaminated with heparin, clotted specimens, or unprocessed specimens not delivered to the laboratory within 1 to 2 hr of collection should be rejected.
Nursing Implications and Procedure
Potential nursing problems
|Problem||Signs & Symptoms||Interventions|
|Bleeding (Related to anticoagulant therapy; altered clotting factors; depleted clotting factors)||Altered level of consciousness; hypotension; increased heart rate; decreased HGB and HCT; capillary refill greater than 3 sec; cool extremities||Increase frequency of vital sign assessment with variances in results; monitor for vital sign trends; administer blood or blood products as ordered; administer stool softeners as needed; monitor stool for blood; encourage intake of foods rich in vitamin K; monitor and trend HGB/HCT; assess skin for petechiae, purpura, hematoma; monitor for blood in emesis, or sputum; institute bleeding precautions (prevent unnecessary venipuncture; avoid IM injections; prevent trauma; be gentle with oral care, suctioning; avoid use of a sharp razor); administer prescribed medications (recombinant human activated protien C; epsilon aminocaproic acid)|
|Gas exchange (Related to decreased lung tissue perfusion secondary to embolic obstruction; aveolar dead space; increased shunting secondary to alveolar collapse; ventilation perfusion mismatch)||Cyanosis; increased respiratory rate; anxiety; restlessness; confusion; irritability; tachycardia; dyspnea; headache; abnormal ABG; lethargy; somnolence; decreased oxygen saturation (less than 90%); adventitious breath sounds (crackles); areas of decreased lung ventilation; cough, hemoptysis, pleuritic pain in the presence of pulmonary infarct||Monitor and trend ABG results; monitor respiratory rate and effort; monitor and trend pulse oximetry; monitor and trend vital signs; ensure patient does not cross legs while lying or sitting; assess lung sounds frequently; use pulse oximetry to monitor oxygen saturation; collaborate with physician to administer oxygen as needed; elevate the head of the bed 30 degrees; assess for hypoxia symptoms; administer prescribed anticoagulant therapy|
|Bleeding (Related to altered clotting factors secondary to anticoagulant therapy)||Altered level of consciousness; hypotension; increased heart rate; decreased HGB and HCT; capillary refill greater than 3 sec; cool extremities||Increase frequency of vital sign assessment with variances in results; monitor for vital sign trends; administer blood or blood products as ordered; monitor stool for blood; encourage intake of foods rich in vitamin K; monitor and trend HGB/HCT, INR, PT, PTT; ensure that anticoagulant therapy is accurately administered (IV, PO); assess skin for petechiae, purpura, hematoma; monitor for blood in emesis, or sputum; institute bleeding precautions (prevent unnecessary venipuncture; avoid IM injections; prevent trauma; be gentle with oral care, suctioning; avoid use of a sharp razor)|
|Tissue perfusion (Related to vessel wall injury; blood hypercoagulability)||Femoral, popliteal, or small calf vein tenderness, warmth at involved area, pain with leg palpation, edema; it is possible to be asymptomatic if the DVT is located in a distal vein||Assess for symptoms of DVT; assess for contributing factors (trauma, recent surgery, smoking, varicose veins, age, venous stasis, obesity, pregnancy, oral contraceptive use); monitor diagnostic test results (d-dimer, ultrasound, impedance plethysmography); monitor and trend coagulation studies (PT, INR, PTT); encourage bedrest with leg elevation; administer prescribed anticoagulant therapy; institute bleeding precautions (avoid IM injections, prevent trauma, be gentle with oral care and suctioning, avoid use of a sharp razor); apply moist heat at affected area; apply leg compression devices as prescribed; prepare for potential adjunct therapy (thrombolytic, vena cava filter, thrombectomy)|
- Positively identify the patient using at least two unique identifiers before providing care, treatment, or services.
- Patient Teaching: Inform the patient this test can assist in diagnosing diseases associated with clotting disorders.
- Obtain a history of the patient’s complaints, including a list of known allergens, especially allergies or sensitivities to latex.
- Obtain a history of the patient’s hematopoietic system, any bleeding disorders, symptoms, and results of previously performed laboratory tests and diagnostic and surgical procedures.
- Note any recent procedures that can interfere with test results.
- Obtain a list of the patient’s current medications, including anticoagulants, aspirin and other salicylates, herbs, nutritional supplements, and nutraceuticals (see Effects of Natural Products on Laboratory Values online at DavisPlus). Note the last time and dose of medication taken.
- Review the procedure with the patient. Inform the patient that specimen collection takes approximately 5 to 10 min. Address concerns about pain and explain that there may be some discomfort during the venipuncture.
- Sensitivity to social and cultural issues, as well as concern for modesty, is important in providing psychological support before, during, and after the procedure.
- Note that there are no food, fluid, or medication restrictions unless by medical direction.
- Potential complications: N/A
- Avoid the use of equipment containing latex if the patient has a history of allergic reaction to latex.
- Instruct the patient to cooperate fully and to follow directions. Direct the patient to breathe normally and to avoid unnecessary movement.
- Observe standard precautions, and follow the general guidelines in Patient Preparation and Specimen Collection. Positively identify the patient, and label the appropriate specimen container with the corresponding patient demographics, initials of the person collecting the specimen, date, and time of collection. Perform a venipuncture. Fill tube completely. Important note: When multiple specimens are drawn, the blue-top tube should be collected after sterile (i.e., blood culture) tubes. Otherwise, when using a standard vacutainer system, the blue-top tube is the first tube collected. When a butterfly is used, due to the added tubing, an extra red-top tube should be collected before the blue-top tube to ensure complete filling of the blue top tube.
- Remove the needle and apply direct pressure with dry gauze to stop bleeding. Observe/assess venipuncture site for bleeding or hematoma formation and secure gauze with adhesive bandage.
- Promptly transport the specimen to the laboratory for processing and analysis. The CLSI recommendation for processed and unprocessed samples stored in unopened tubes is that testing should be completed within 1 to 4 hr of collection.
- Inform the patient that a report of the results will be made available to the requesting HCP, who will discuss the results with the patient.
- Depending on the results of this procedure, additional testing may be performed to evaluate or monitor progression of the disease process and determine the need for a change in therapy. Evaluate test results in relation to the patient’s symptoms and other tests performed.
- Instruct the patient to report bleeding from skin or mucous membranes, ecchymosis, petechiae, hematuria, and occult blood.
- Inform the patient with increased levels of fibrin degradation products of the importance of taking precautions against bruising and bleeding, including the use of a soft bristle toothbrush, use of an electric razor, avoidance of constipation, avoidance of acetylsalicylic acid and similar products, and avoidance of IM injections.
- Reinforce information given by the patient’s HCP regarding further testing, treatment, or referral to another HCP.
- Answer any questions or address any concerns voiced by the patient or family.
- Teach patient that crossing legs increases DVT risk.
Expected Patient Outcomes
- States the purpose of anticoagulant therapy as to prevent more clot formation.
- States understanding that the purpose of heat application to the affected area is to relieve pain and inflammation.
- Demonstrates proficiency with deep breathing exercises.
- Demonstrates proficiency in self-administration of ordered anticoagulant therapy.
- Complies with the request to maintain bedrest until the HCP deems it is safe to resume activity.
- Complies with the request to refrain from risky activities to prevent injury
- Related tests include aPTT, ALT, alveolar/arterial gradient, angiography pulmonary, AT-III, AST, bilirubin, biopsy liver, blood pool imaging, BUN, coagulation factors, CT cardiac scoring, creatinine, CBC, CK and isoenzymes, CRP, d-dimer, exercise stress test, FDP, fibrinogen, GGT, lung perfusion scan, lung ventilation scan, myoglobin, plasminogen, platelet count, PET heart, procalcitonin, protein S, PT/INR, troponin, US venous Doppler extremity studies, and venography lower extremity studies.
- Refer to the Hematopoietic System table at the end of the book for related tests by body system.