dvt ch 31, aneurysm 31
Risk factors include
increasing patient age, active cancer with or without concurrent chemotherapy, varicose veins, prior venous thrombosis, pregnancy, postpartum period, and oral contraceptive and hormone therapy. Surgery, trauma, hospital or nursing home confinement resulting in immobility, and procedures such as central vein catheterization or transvenous pacemaker insertion also increase the risk.
The aPTT evaluates the
intrinsic coagulation cascade and is used to evaluate the effectiveness of heparin.
The Wells score
is a PTP scoring system that categorizes patients as high, moderate, or low probability. This is based on the presence of clinical features commonly associated with DVT and identification of an alternative diagnosis.
post thrombotic syndrome (PTS)
is a chronic disorder with clinical features that range from minor limb swelling and discomfort to severe leg pain, intractable edema, irreversible skin changes, and leg ulceration. Prevention of PTS with the use of thromboprophylaxis is important because treatments are not very effective.
Cardiac MRI
is an imaging modality that has shown improved sensitivity and specificity versus TTE in detecting aortic dilation. The lack of radiation exposure with MRI compared with CT may make it the imaging modality of choice for aortic dilation.
Chronic inflammation (aortitis)
is implicated in the development of aneurysms.
A false or pseudoaneurysm
is not a distortion of the vessel wall but rather a leak from the artery. The leak is confined by the surrounding tissues, and eventually a blood clot forms.
Surgical management
is rarely utilized to remove a DVT unless there is a massive occlusion that does not respond to medical treatment and the thrombus is of recent (1-2 days) onset. Thrombectomy is the most common surgical procedure for removing a clot.
Marfan's syndrome
is the hereditary disease most closely linked to aneurysm. This syndrome results in the degeneration of the elastic fibers of the aortic media.
Aortic dissection (dissecting aneurysm)
is thought to be caused by a sudden tear in the aortic intima creating a false lumen in the artery opening the way for blood to enter the aortic wall. -Degeneration of the aortic media may be the primary cause for this condition, with hypertension being an important contributing factor.
In pregnant women,
it has an incidence of 0.5 to 7 per 1,000 pregnancies. It is the second-most common cause of maternal death in developed countries after bleeding.
In addition to antihypertensive medications,
macrolides and tetracyclines, antibiotics that may inhibit secondary infections implicated in aneurysm development, have been proposed as a treatment for AAA with varying rationales and degrees of success.
In patients with a higher risk of bleeding
mechanical VTE prophylaxis is indicated. This includes the use of graduated compression stockings, venous foot pumps, and active external intermittent compression devices.
In patients with a low bleeding risk pharmacological prevention is recommended-
medications include low molecular weight heparin (LMWH), unfractionated heparin, or, in patients with heparin-induced thrombocytopenia (HIT), fondaparinux can be used.
Deep vein thrombosis is more common where
more common in the veins of the lower extremity, develop in the deep veins of the calf muscles or, less frequently, in the proximal deep veins of the lower extremity or upper arm. When the circulation of the blood slows down because of illness, injury, or inactivity, blood can accumulate or "pool," which provides an ideal setting for clot formation.
Most people with an aneurysm less than 5 cm in diameter are advised
not to have immediate surgery. The goal for patients who do not require immediate surgical intervention is to monitor the growth of the aneurysm over time and to maintain the BP at a normal level to decrease the risk of rupture.
The clot(s) can cause partial or complete blockage of circulation in the vein, which can lead to
pain, swelling, tenderness, discoloration, or redness and warmth in the affected area.
Diagnostics include a combination of
pre-test probability (PTP) testing, D-dimer testing, and compression ultrasonography (CUS).
The purpose of vena cava interruption is to
prevent PE. In this procedure, a provider surgically positions a filter inside the inferior or, not routinely, the superior vena cava between the DVT and the heart. Blood flows normally through the umbrellalike filter, but emboli are trapped, ensuring that they do not reach the lungs.
Treatment is focused on
reducing the growth rate and preventing the complications of aneurysms. -Hypertension is an important risk factor for rupture, so BP is aggressively managed with antihypertensive medications such as angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers (ARBs), and/or beta blockers.
For those with small or asymptomatic aneurysms,
regular ultrasounds or CT scans are necessary to monitor the growth of the aneurysm.
The most common surgical procedure for AAA has traditionally been a
resection and repair (aneurysmectomy). In this procedure, the aneurysm is excised, and a graft is applied.
An ECG is also
routinely done to rule out an MI because complications of aneurysm usually involve chest pain.
The clinical manifestations vary depending on the
size, location, degree of vessel occlusion, and adequacy of collateral circulation.
Rupture causes
sudden and extreme loss of blood. -Patients may present similar to those with a dissection with symptoms such as pain, tachycardia, and differing BPs between extremities, but in extreme cases, pain occurs then loss of consciousness due to hypovolemic shock from massive blood loss.
Classic signs and symptoms of aortic dissection are
sudden onset of severe and persistent pain described as "tearing" or "ripping" in the anterior chest or back and extending to the shoulders, epigastric area, or abdomen. -Diaphoresis, nausea, vomiting, faintness, and tachycardia are also common. -Blood pressure is often markedly different from one extremity to another and often decreases because of loss of blood.
Computed tomography scanning with IV contrast is considered
the gold standard for assessing the size and location of an abdominal or thoracic aneurysm.
Deep vein thrombosis is much less common in
the pediatric population. Approximately 1 in 100,000 children younger than 18 years experience a DVT. This is possibly because of a child's higher heart rate, relatively active lifestyle, and fewer comorbidities when compared with adults.
Hemodynamic decompensation occurs not only because of physical obstruction of blood flow but also because of
the release of humoral factors such as serotonin from platelets, thrombin from plasma, and histamine from tissue.
The clinical manifestations of DVT vary depending on
the size, location, degree of vessel occlusion, and adequacy of collateral circulation. Patients may complain of pain, and there may be redness, swelling, and warmth due to obstruction of flow in the affected extremity.
The use of thrombolytic therapy such as
tissue plasminogen activator (tPA) is not routinely administered in patients with DVT. thrombolytics are only used under certain circumstances. They include patients who have failed conventional therapy with a clot that has been present for fewer than 14 days and have a low bleeding risk. Further assessment is made based on individual patient circumstances such as size and location of the clot and preexisting conditions.
Blunt trauma,
usually from motor vehicle crashes, can cause aneurysms in the descending thoracic or abdominal aorta. More importantly, blunt trauma can cause rupture of the aorta.
■ Actions
• Administer antihypertensives as ordered• Administer statins as ordered• Administer tetracyclines and macrolides as ordered• Administer stool softeners as ordered• Create calm environment to reduce stress
• Prevention of reoccurrence with activities such as:
• Early ambulation and active leg exercises• Monitor for adequate fluid intake to prevent dehydration and changes in blood flow• Avoid constricting clothing on the legs that might decrease venous flow, sitting with knees bent or crossed for long periods, standing for long periods• Remind patients that long car or airplane trips can increase the risk of DVT, so they should stay well hydrated and move around whenever possible or do leg exercises while sitting
teaching
• Following a strict treatment regimen which includes• Compliance with medications• Smoking cessation program if the patient is a smoker• Maintaining a healthy weight• Regular exercise• Avoid crossing or elevating legs to decrease pressure on the aorta and iliac arteries
Nursing Diagnoses
• Ineffective peripheral tissue perfusion related to interruption of venous blood flow• Acute pain related to vascular inflammation and irritation and edema formation• Risk for impaired physical mobility related to pain and discomfort of the affected extremities
Nursing Diagnoses
• Risk for ineffective peripheral tissue perfusion related to interruption of arterial blood flow• Acute pain related to vascular enlargement, dissection or rupture• Fear related to threat of injury or death or the surgical intervention
PE Clinical manifestations include:
• Shortness of breath • Decreased oxygen saturation • Tachycardia, hypotension • Sweating • Sharp chest pain (especially during deep breathing) • Hemoptysis (bloody sputum)-- r/t the clot in the pulmonary vasculature blocking flow through the lungs preventing oxygenation and ventilation, increasing pulmonary vascular resistance (PVR), increasing the workload on the right heart, and decreasing oxygen supply to the lung tissue itself.
Pseudoaneurysms are typically caused by
iatrogenic trauma that punctures the artery. They are a known complication of percutaneous arterial procedures such as arteriography.
Macrolides
(Antibiotics) Inhibit abdominal aortic aneurysm (AAA) progression by reducing secondary infection within aortic wall
Tetracyclines
(Antibiotics) Inhibit matrix metalloproteinase (MMP), which is involved in aneurysm formation; decrease the rate of aneurysm expansion
PRETEST - One point is given for each positive finding in the pretest, and 2 points are subtracted if an alternative diagnosis as likely as DVT is identified.
1. Active cancer (treatment within last 6 months or palliative) = 1 point 2. Calf swelling greater than 3 cm compared to other calf (measured 10 cm below tibial tuberosity) = 1 point 3. Collateral superficial veins (nonvaricose) = 1 point 4. Pitting edema (confined to symptomatic leg) = 1 point 5. Previously documented DVT = 1 point 6. Swelling of entire leg = 1 point 7. Localized pain along distribution of deep venous system = 1 point 8. Paralysis, paresis, or recent cast immobilization of lower extremities = 1 point 9. Recently bedridden greater than 3 days, or major surgery requiring regional or general anesthetic in past 4 weeks = 1 point 10. Alternative diagnosis at least as likely - subtract 2 points
Pathophysiology
Virchow's triad describes the factors implicated in the formation of a venous thrombosis; decreased flow rate of the blood or stasis of blood flow, damage to the blood vessel wall; endothelial injury, and an increased tendency of the blood to clot (hypercoagulability).
• Avoid use of sequential compression devices (SCDs) in affected extremity
An SCD may cause the thrombus to break away, resulting in an embolus.
Pathophysiology
An aneurysm is a permanent localized dilation of an artery that forms when the middle layer (media) of the artery is weakened, producing a stretching effect in the inner layer (intima) and outer layers of the artery. While the artery widens, tension in the wall increases, further widening occurs, and the aneurysm enlarges. The diameter of the artery can be enlarged to at least two times the normal circumference. Hypertension is one cause of that tension and enlargement within the artery.
• Neurological assessment
An aneurysm of the aortic arch can cause neurological symptoms similar to those of a TIA or stroke. The bulging aorta exerts pressure on the subclavian artery, decreasing blood flow through the common carotid arteries to the brain, causing neurological effects.
• Administer anticoagulation medications as ordered
Anticoagulation with unfractionated heparin followed by long-term oral anticoagulation prevents the formation of new thrombi and inhibits the growth of the existing thrombi.
• Early ambulation
Bedrest has been recommended in the past, but recent studies show early ambulation does not result in more complications (see Evidence-Based Practice) and is key to prevention.
calf thrombosis
Calf thrombosis Calf tenderness Distal swelling of affected extremity
• Assess extremity for pain, tenderness, warmth, redness, or swelling
Common symptoms of DVT that occur because of obstruction of blood flow and may indicate location of the clot
Syphilis, patients born with bicuspid aortic valve, and
Ehlers-Danlos syndrome, a rare genetic disorder, are other causes of AAAs.
Genetics are a major factor in aortic aneurysms.
Familial clustering of aortic aneurysms has been observed, with an estimated 15% to 20% incidence occurring in first-degree relatives of the individual with an aneurysm.
femoral thrombosis
Femoral thrombosis Tenderness and pain in distal thigh and popliteal regions Swelling more prominent than with calf vein thrombosis alone Swelling may extend to knee
DVT RISK CLASSIFICATION
High probability = 3 points Moderate probability = 1-2 points Low probability = 0 points
• Vital signs
Hypotension and tachycardia may indicate hypovolemia secondary to a loss of circulating volume. Blood pressure may vary between extremities if dissection is occurring because of the lessening of blood flow distal to the dissection. Hypertension, elevated diastolic pressure, and tachycardia can further weaken the vessel wall, increasing the risk that the aneurysm will enlarge, dissect, or rupture.
• Vital signs with oxygen saturation
Hypotension, tachycardia, and decreased oxygen saturation could indicate the presence of a PE or bleeding, especially if the patient is anticoagulated.
• Laboratory values:
INR, PT/aPTT, hemoglobin, and hematocrit • The INR and PT/aPTT should be prolonged. • The hemoglobin and hematocrit should be within normal limits.
ileofemoral thrombosis
Iliofemoral thrombosis Massive swelling in affected extremity Tenderness and pain involving entire extremity
• Gentle palpation to inspect for induration
Induration (hardening) helps to locate the placement of the clot in the blood vessel.
• Compliance with regular laboratory monitoring
It is important that the patient (and family) understand the importance of compliance with laboratory draws and the medication regimen to reduce bleeding risk. • Safety precautions when taking anticoagulants (see Safety Alert)
• Signs and symptoms of bleeding such as bruising, bloody stools, petechiae
It is important when taking anticoagulants that the patient (and family) is able to detect signs and symptoms of bleeding.
• Compare right and left calf, thigh, or arm circumferences
Localized edema due to obstruction to blood flow in one extremity may suggest a DVT.
Contrast venography, CT venography and
MRI venography are other diagnostic tools but are rarely needed or utilized. These alternatives to ultrasound may be beneficial in selective cases, such as in the morbidly obese or when pelvic or abdominal thrombosis is suspected.
Dissection is also frequently linked with
Marfan's syndrome. This is a life-threatening emergency because of the loss of circulation to any major artery arising distal to the dissection. The ascending and descending thoracic aortae are the most common sites, but dissections can also occur in the abdominal aorta
• D-dimer test
Measures fibrin degradation products produced from clot breakdown. A positive result stratifies the patient into a high-risk category for DVT.
Epidemiology
Men develop AAAs four to five times more often than women. Caucasians develop AAAs more commonly than other racial groups. -Thoracic aortic aneurysms (TAAs), the most common site for a dissecting aneurysm, occur most often in men between the ages of 40 and 70 years and have a high mortality rate even with surgical intervention.
Assessment and Analysis
Most AAAs are small and do not cause any symptoms. The vast majority of thoracic aneurysms are silent, with rupture or dissection constituting the first symptoms. Overall, only 5% to 10% of patients experience symptoms such as chest, back, or flank pain depending on the location of the aneurysms.
Elective Surgery
Most abdominal aortic aneurysms occur in patients between 60 and 90 years of age. -Rupture is likely with coexisting hypertension and with aneurysms more than 6 cm wide. -At this point, the risk of rupture is greater than the risk of death during surgical repair. Therefore, elective surgical repair should be considered carefully if the patient is able to withstand surgery and anesthesia. ----It is important that the healthcare team provides the patient and family with all the facts regarding the risk and benefit in order for the patient and family to make the most informed decision.
abdominal aneurysm
Pain Pain occurs in the back and abdomen because of impingement on adjacent structures and stretching of aortic tissue Abdominal throbbing Noticeable, small pulsating mass near the navel due to increased aortic pressure Cyanosis Blood clots Blood can pool in the part of the aorta that is bulging, and a blood clot can develop inside the aneurysm. If the clot breaks loose, symptoms such as pain, numbness, tingling, and cyanosis may result.
Thoracic Aneurysm
Pain (constant) Caused by stretching of the aortic tissue and impingement on adjacent structures Heart failure Ascending aneurysms may produce heart failure and its associated symptoms by causing aortic regurgitation. As the aortic root enlarges, the aortic valve leaflets are pulled away from each other, permitting backward leakage of blood. Dyspnea Cough Respiratory symptoms caused by distortion and obstruction of trachea by the aneurysm Hoarseness of voice Dysphagia Caused by distortion of the phrenic nerve or direct impingement on the esophagus by the aneurysm
• Peripheral sensation and motor response
Paresthesias or paralysis may indicate pressure against the arteries supplying the spinal cord.
The presence of Homans' sign,
calf pain elicited on dorsiflexion of the foot, may indicate the presence of a DVT but its routine use in evaluation is not recommended as it is frequently misinterpreted and is not a reliable predictor.
Evaluating Care Outcomes
Patients with a DVT can be safely managed by complying with prescribed anticoagulation therapy in combination with ambulation, compression stockings, and extremity elevation when resting. Stable vital signs and oxygen saturation along with decreased pain, swelling, and tenderness indicate a resolving DVT. Adjustments in anticoagulation therapy may be needed to maintain target laboratory values or prevent bleeding. Preventive patient teaching for high-risk individuals is essential to prevent initial and reoccurring DVT and PE. Patients should be able to maintain a healthy, active lifestyle by making adjustments in daily life that decrease DVT risk and by maintaining compliance with the treatment regimen.
.Evaluating Care Outcomes
Patients with aortic aneurysms can achieve a good outcome by complying with the prescribed therapy. Blood pressure and HR within normal limits, strong peripheral pulses, normal skin color and texture, no complaints of abdominal, back, or chest pain, no complaints of wheezing and shortness of breath, no complaints of dysphagia or hoarseness, and a normal neurological assessment indicate a stable aneurysm.
patients with TAAs measuring 2.8 in. (7 cm) in diameter or with AAAs measuring 2 in. (5 cm) in diameter or those with smaller aneurysms that are producing symptoms are advised to have
elective surgery (see Geriatric/Gerontological Considerations). A small aneurysm that expands more than 0.5 cm over a 6-month period of time should also be repaired surgically.
• Pain
Persistent abdominal, chest, or back pain indicates that the aneurysm is pushing on adjacent organs and structures and may help pinpoint the location. Pain is also an indicator of a change such as dissection or rupture.
The PT/INR evaluates the
extrinsic coagulation cascade and is used to evaluate the effectiveness of warfarin.
Risk factors include
family history, advanced age, male gender, smoking, atherosclerosis, treated and untreated hypertension, high total serum cholesterol, known coronary artery disease, and genetic and/or metabolic abnormalities. Atherosclerosis accounts for 75% of all AAAs, but of these risk factors, smoking is one of the most important.
• Patients with Marfan's syndrome should be encouraged to do regular screening and call their provider with any new chest, abdominal, or flank pain.
Patients with Marfan's syndrome are at increased risk for aneurysms due to the degeneration of the elastic fibers of the aortic media that occurs with that disease. Because of the emergent nature of aortic dissection, immediate recognition is essential to allow emergent repair.
• Encourage adequate fluid intake
Prevents dehydration and sluggish blood flow, which exacerbates DVT growth
• Gentle abdominal auscultation and palpation
Pulsatile abdominal masses may indicate an AAA. A bruit is caused by turbulent flow through the aneurysm.
Statins
Reducing the progression of atherosclerosis may influence aneurysm growth.
• Compression stockings
Should be worn at all times. Compression promotes venous return and decreases leg swelling.
• Assess for signs of bleeding such as bruising, petechiae, hematuria, bloody stools
Signs of bleeding may indicate a need to modify or decrease anticoagulation therapy.
• Administer thrombolytic agent as ordered
Thrombolytic agents dissolve existing thrombi and decrease the instance of vascular damage.
upper extremity thrombosis
Upper-extremity thrombosis Swelling of affected extremity Dilated superficial veins Tenderness and pain Impaired mobility of extremity
• Peripheral pulses, skin color, and temperature
Weak peripheral pulses, poor color, and cool extremities indicate lack of arterial flow, potentially because of dissection or thrombus formation in the aneurysm.
• Leg elevation
When at rest, the affected extremity should be elevated at least 10 to 20 degrees above heart level to enhance venous return and reduce swelling.
descending aortic aneurysms or thoracic aneurysms are located
above the diaphragm
In true aneurysms,
all three layers of the arterial wall are weakened. True aneurysms are further classified by their shape or form (Fig. 31.11). The most common forms are saccular and fusiform. A saccular aneurysm projects from only one side of the vessel. If an entire arterial segment becomes dilated, a fusiform aneurysm develops.
Medication therapy typically consists of
anticoagulation with unfractionated heparin or low molecular weight heparin (LMWH) followed by long-term oral anticoagulation with warfarin, and Newer oral anticoagulant agents, including direct thrombin inhibitors (e.g., dabigatran etexilate) and direct factor Xa inhibitors (e.g., rivaroxaban, apixaban, and edoxaban)
Intermittent compression devices
apply external pressure to the limb which promotes blood flow velocity, reduces venous stasis, and increases levels of systemic fibrinolysis. Despite widespread use, there is limited evidence regarding the use of graduated compression stockings, venous foot pumps, or combined medical and mechanical prophylaxis.
Ascending aortic aneurysms are located in the
arch of the aorta,
Other less-invasive surgical procedures include
balloon angioplasty, stent placement, and vena cava interruption. Balloon angioplasty widens the vein after a blood clot has been dissolved. As with other balloon angioplasty procedures, expanding the balloon in the vein causes the vein to widen and improves blood flow. Stent insertion can be utilized for DVT patients who have a vein that is prone to collapse. The stent expands once inserted and acts as a support for vein walls.
abdominal aortic aneurysms (AAAs) are located
below the diaphragm in the abdomen.
Surgical repair is associated with risks that include
bleeding, infection, MI, renal failure, and graft occlusion. Benefits versus risks should be weighed when considering an elective surgical repair of the aneurysm.
Deep vein thrombosis (DVT) is a
blood clot in a large vein, usually in the leg or pelvis. If the circulating clot moves through the heart to the lungs, it can block an artery supplying blood to the lungs. This condition is called pulmonary embolism (PE). the disease process that includes DVT and/or PE is called venous thromboembolism (VTE).
endovascular aneurysm repair (EVAR)
has gained acceptance as an alternative to open surgical repair with reduced periprocedural risks. The endovascular alternative is an endothelial stent graft or EVAR, which involves the transluminal placement and attachment of a sutureless aortic graft prosthesis across an aneurysm. The aneurysm eventually shrinks down onto the stent graft
Abdominal ultrasound or transthoracic echocardiography (TTE)
have also been preferred screening modalities because they can be done quickly and efficiently at the bedside and because of their noninvasive nature and lack of radiation.
Elastic compression stockings (ECSs)
have the potential to prevent PTS by reducing venous hypertension and reflux, which are thought to be principal factors in the pathophysiology of PTS.
Clinical manifestations typically occur when a complication such as
dissection or rupture occurs. -There may be a palpable pulsatile mass in the abdomen with the AAA. -Sometimes the patient presents with chest, back, or flank pain depending on the location of the aneurysm. -The pain is typically not related to any activity and occurs spontaneously. -Pain generally reflects a change in the aneurysm that needs immediate attention.
In low risk patients,
early ambulation may be all that is necessary. Venous thromboembolism (VTE) prophylaxis is indicated in at-risk hospitalized populations.