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DVT, Thrombophlebitis, PE
Terms in this set (54)
three broad categories of factors that are thought to contribute to thrombosis.
1. Alterations in normal blood flow
2. Injuries to the vascular endothelium
3. Alterations in the constitution of blood (hypercoagulability)
The words, Virchow's Triad
came about when Rudolph Virchow in 1856: Virchow found that venous thrombo-embolism (VTE) might be precipitated by venous stasis secondary to immobility as well as by changes in the vessel wall and in blood
Three factors that are responsible for DVT are
Vascular wall injury
Hypercoagulability of blood
occurs when blood return from the legs is impaired. The blood pools in the legs, allowing clotting factors to reach levels high enough to initiate clotting. Like a vessel wall damage, venous stasis occurs mainly in the lower extremities, however, it can develop in any immobilized limb.
Vessel wall or endothelial damage
occur in the pelvis and legs. The vessel's lining of endothelial cells inhibits platelet adhesion and aggregation. An injury that breaks this surgace exposes platelets in the bloodstream to collagen in the subendothelium. This, in return, triggers the release of a substance that causes the platelets to collect at the injured site.
Hypercoagulability of blood:
Several conditions predispose a p/c to hypercoagulability, the increased tendency for blood to clot. These and other risk factors for DVT are listed in the table.
Venous stasis: causes
1. Immobility > 3day
2. Compression of iliac or femoral veins from tumors, obesity, pregnancy
3. Lengthy surgery
6. Varicose veins
Endothelial damage: causes
3. Indwelling IV catheter
4. Injection of irritants
5. IV drug abuse
6. Prior DVT
2. Estrogen Rx
5. Sickle cell disease
Numerous Venous Disorders
Deep Vein Thrombosis (DVT)
Chronic Venous Insufficiency
Venous Thrombosis, DVT, Thrombophlebitis
are often used interchangeably, but they are not identical disease processes. A venous thrombosis is a blood clott that forms within a vein. It is usually in the lower extremities; superficial or deep veins may be affected.
Thrombophlebitis VS DVT
Thrombus associated with inflammation; most frequently lower extremities. Usually superficial
Deep vein thrombosis:
Commonly called DVT (Deep Vein Thrombosis)). More serious than superficial; puts pt at risk for Pulmonary Embolism (PE)
Other terms: Phlebothrombosis (clot without inflammation); Phlebitis (vein inflammation, for instance from IV)
causes a painful swelling along the course of the veins close to the surface of the skin. The pain may vary from moderate discomfort to a cramp-like pain. The pain gradually subsides over a period of one to two weeks, leaving hard clots that can be felt along the course of the veins.
rarely associated with deep venous disease and experts say that it does not seem to be a risk factor for PE
may be more difficult to diagnose as it may occur without signs or symptoms. There may be pain, swelling and tenderness - these occur most commonly in the calf, but may occur anywhere in the leg up to the groin. It is possible to confuse the symptoms of a DVT with those of other conditions such as muscle strain, or infection involving the skin or muscle.
danger of a DVT
the clot may dislodge and travel through the circulatory system to the lungs - a clot in the lungs is referred to as a pulmonary embolism (PE). A PE will cause shortness of breath and chest pain, and can be life-threatening. All DVTs must be treated immediately to prevent this occurring. Unfortunately, in some cases a PE may be the first sign of a DVT.
Note: Thrombosis Superficial Veins
Pain, tenderness, redness and warm.
Low risk of dislodgement of clot. Most dissolve spontaneously
Usually treated at home with bedrest, elevation of leg and anti-inflammatories.
Causes: IVs, trauma, sometimes repetitive motion
DVT: A Blood Clot in Leg Vein
A blood clot in a leg vein may cause pain, warmth and tenderness in the affected area.
Risk Factors for DVT
Immobility: greatest risk
Endothelial damage: trauma, surgery, pacing wires, central lines, local vein damage
Venous stasis, Coagulopathy, Cancer
Pregnancy, Oral contraceptive use
Congenital proteins C & S
Antithrombin III deficiency
Recent major surgery, UC, HF, hypercoagulation
Nurse should examine the area described as being painful and compare to the opposite limb. Look for warmth, edema, swelling of the extremity. Determine swelling. Use tape measure. Tenderness usually develops later as vein walls become inflammed.
Signs and Symptoms:
Site: Pain, tenderness, erythema
Swelling: Check leg circumferences by measurement
Homan's sign (NOT DIAGNOSTIC!!!!)
Pulmonary Embolism is often the first sign, unfortunately.
Do not massage the affected area/limb
Homan's Sign: Not diagnostic, but still around...
Dorsiflexion of the foot causes pain.
Positive in about 10% of clients with DVT
False positives common.
Lack of sensitivy and specificity
Clinical Manifestations of DVT
Can be asymtomatics
Classic: Calf or groin tenderness, sudden onset of unilateral leg swelling
Phlemgasia cerulea dolens (Painful blue edema; very uncommon. Half the time associated with malignancy)
Phlemgasia cerulea dolens
Painful blue edema; very uncommon. Half the time associated with malignancy
More Clinical Symptoms: DVT
Swollen distal (ankles)
Different leg circumferences
Increased surface temperature
Complications of DVT
Chronic venous occlusion
Coagulation studies: APTT, PTT, & PT
Doppler compression ultrasound & Duplex imaging
ESR test, D-Dimer, may have elevated white count
Coagulation Studies: APTT
(Activated Partial Thromboplastin Time; 20-35 sec), PTT (60-70 sec), PT (prothrombin time; 11-15) are tested to detect clotting factor defects. APTT is the most sensitive than other two, since the activator added in vitro shortens the clotting time which in turn can detect the minor clotting defects as well. P/C with DVT, MI, PE, digitalis, diuretics, Vit K, Rifampin and barbiturates have low PT level. P/c with liver disease, CHF, antibiotics, Dilantin, heparin have high PT level.
A contrast dye is injected into the venous system, from the ankle area, allowing visualization of the veins by showing filling or absence of filling. This test is useful for identifying venous obstruction caused by a DVT
Identifies changes in blood blow secondary to presence of a thrombus. It may take 6 to 72 hours for isotope to collect at the thrombus sit; thus the scanner will be used to check the leg daily for 3 days.
Estimates blood flow using measures of resistance and normal changes tha occur during pulsatile blood folw.
Erythrocyte sedimentation rate measures the rate at which RBCs settle in unclotted blood in millimeters per hour. ESR in young men (0-15mm/hr), older men (0-20), young females (0-20), and old females (0-30). The rate increases in acute inflammatory process, infections, tissue damages.
Medical Management DVT
Drug therapy: Could be anticoagulation therapy with Heparin (usual), sometimes coumadin
Rarely: Thrombolytic therapy (tPA), pharmomechanical thrombectomy—under anethesia catheter into occluded vein with tPA directly to clot
Goal: Prevent thrombus from growing and fragmenting
Heparin Therapy for DVT
Prevention of new clots, enlargement of exisiting
Labs (PT, aPTT, INR) checked before, during after...
Usually a loading dose 100 units/kg of body weight
Then IV infusion based on body weight
Low-molecular weight heparin
Lovenox most common
Prevents and treats: most commonly prescribed for prevention
Monitoring of INR, occult blood in stool
ID p/c at risk
Increase po fluid intake
Promote leg exercise to prevent stasis
Prescribe antiembolic stockings/ SCDs
Administration of therapeutic anticoagulants to prevent pulmonary embolism
Lovenox (Enoxaprin) [SQ] is used to bind with few plasma proteins, therefore, there is a more predictable dose response; the drug doesnot affect PTT, so there is no need to monitor this lab value. It also does not significantly change fibrinogen levels or inhibit platelet aggregation at the site of vascular injury, so it may cause less bleeding. It does not require IV infusion.
Warfarin or Coumadin is used for the p/c within 72 hours of heparin RX. Continue heparin Rx until the p/c's international normalized ratio (INR) is between 2 and 3 which usually occurs within 5 days.
Compression stockings (also called support stockings) compress your legs, promoting circulation. A stocking butler may help you put on the stockings.
Sequential Compression Devicies
PULMONARY EMBOLISM (PE)
Caused by clot passing into the pulmonary artery or its branches, with resulting obstruction of the blood supply to lung tissue and subsequent collapse.
Most common pulmonary complication from thrombus/thrombi.
PEs have a high risk of mortality.
Pulmonary Emboli in Lung Artery
Embolism travels up the femoral vein, through inferior vena cava to heart and lungs, and then causes infarction of the lower lungs
Sudden onset of dyspnea
Sharp chest pain
History of airplane flight, long travel
Hx of being bedridden
Hx of DVT
PE: DIAGNOSTIC TESTS
D-Dimer: highly sensitive, not specific. If D-Dimer neg, no PE. If high, not necessarily PE.
EKGs can rule out other causes of chest pain.
IV therapy of heparin & fluid administration
Surgery: Vena caval ligation
is a fibrin degradation product (or FDP), a small protein fragment present in the blood after a blood clot is degraded by fibrinolysis. It is so named because it contains two cross-linked D fragments of the fibrin protein.D-dimer is especially useful when a health practitioner thinks that something other than deep vein thrombosis or pulmonary embolism is causing the symptoms. It is a quick, non-invasive way to help rule out abnormal or excess clotting. However, it should not be used when the probability of pulmonary emobism is high based on clinical assessment.
positive D-dimer result
A positive D-dimer result may indicate the presence of an abnormally high level of fibrin degradation products. It indicates that there may be significant blood clot (thrombus) formation and breakdown in the body, but it does not tell the location or cause. For example, it may be due to a venous thromboembolism (VTE) or disseminated intravascular coagulation (DIC). Typically, the D-dimer level is very elevated in DIC.
1. heparin (IV or SQ), antidote: protamine-sulfate, lab test: PTT 1.5 - 2.5 > normal
2. Warfarin: (PO), antidote: vitamin K, lab test: PT 1.25 - 1.5x > normal
Anticoagulation Therapy continued
Heparin is treatment of choice. It is started stat in patients without bleeding or clotting disorders and in whom Pes are strongly suspected. Initial dose is IV bolus of 5000-10,000 units. Maintenance dose is continuous IV drip after 2-4 hours of initial dose. Goals of RX is to inhibit further thrombus growth, promote resolution of the formed thrombus, and prevent further embolus formation. Protamine Sulfate is an antidote for Heparin and should be available during heparin RX.
PTT (Partial Thromboplastin Time)
levels are monitored to ensure a therapeutic dosage is maintained for heparin (1.5 to 2.5 x normal).
PT (Prothrombin Time)
monitored with the goal of 1.25 - 1.50 x normal.
International Normalized Ratio (INR)
has been advocated by the WHO to compensate for variations encountered with various reagents and methods used in ptothrombin tests. The INR goal for oral anticogulant Rx is 2 - 3.
reverses the effects of Warfarin in 24-36 hour. Fresh frozen plasma may be required in cases of serious bleeding
Inferior Vena Cava filer
May be implanted to prevent new clots.
Typically used when anticoagulation therapy is not indicated. (Brain bleed, about to undergo major surgery)
Only for very high risk patients, not a lot of trials on IVC filters.
PATIENT-FAMILY TEACHING & DISCHARGE PLANNING
Initiate home health referral.
Provide inform re risk factors to the development of thrombi & embolism & preventive measures to reduce risks.
Instruct p/c about S/Sx of the disease.
Patient Education Re Warfarin
Blood draw routinely for PT/INR
Take medication at the same time daily
Don't drink alcohol, ASA
Report to dentist about anticoagulant Rx
Don't increase or decrease leafy vegetable:
Vitamin K affects Warfarin use
Report S/Sx of faintness, dizziness, and weakness
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