Aneurysm, abdominal aortic

Overview-Incidence

Abdominal aortic aneurysm (AAA) is five times more common in men than in women and is three times more common in white men than black men. AAA rupture is the 13th leading cause of death in the United States. Incidence and the risk of rupture increase with age.

Diagnostic Test Results-Imaging

Abdominal ultrasonography reveals the size of the aneurysm and helps detect changes over time; it's also used to detect free blood in the peritoneum with rupture. Plain abdominal radiographs may help identify aortic wall calcification. Computed tomography scanning or magnetic resonance imaging identifies the size of the aorta and determines involvement of visceral and surrounding arteries.

Overview

Abnormal dilation in the arterial wall of the aorta, commonly between the renal arteries and iliac branches Possibly fusiform (spindle-shaped), saccular (pouchlike), or dissecting

Nursing Considerations-Nursing Diagnoses

Acute pain Anxiety Decreased cardiac output Deficient fluid volume Impaired gas exchange Impaired physical mobility Impaired skin integrity Risk for decreased cardiac perfusion Risk for ineffective renal perfusion

Overview-Risk Factors

Advanced age (usually over age 65 years) Male gender White race Positive family history Smoking Hypertension Peripheral vascular disease Chronic obstructive pulmonary disease

Nursing Considerations-For an Intact Aneurysm

Allow the patient to express his fears and concerns and identify effective coping strategies. Encourage the patient to adhere to follow-up evaluations if watchful waiting is used. Offer the patient and his family psychological support. Prepare the patient and family for elective surgery. Weigh the patient, insert an indwelling urinary catheter and an I.V. line, and assist with insertion of the arterial line and pulmonary artery catheter to monitor hemodynamic balance preoperatively. Avoid palpating any pulsatile mass of the abdomen.

Nursing Considerations-Nursing Interventions

Allow the patient to express his fears and concerns and identify effective coping strategies. Encourage the patient to adhere to follow-up evaluations if watchful waiting is used. Offer the patient and his family psychological support. Prepare the patient and family for elective surgery. Weigh the patient, insert an indwelling urinary catheter and an I.V. line, and assist with insertion of the arterial line and pulmonary artery catheter to monitor hemodynamic balance preoperatively. Avoid palpating any pulsatile mass of the abdomen.

Diagnostic Test Results-Diagnostic Procedures

Angiography is the standard for diagnosing AAA, indicated for renal or visceral involvement.

Nursing Considerations-Associated Nursing Procedures

Arterial catheter insertion, assisting Arterial pressure closed monitoring system blood sampling Arterial puncture for blood gas analysis Blood and blood product transfusion Blood pressure assessment Calculating and setting an IV drip rate Cardiac monitoring Cardiac output measurement with iced injectate Cardiac output measurement with room temperature injectate IV bag preparation IV bolus injection IV catheter insertion IV pump use Intake and output assessment Nasogastric tube insertion Nasogastric tube monitoring Neurologic assessment Nutritional screening Oxygen administration Pain management Pulmonary artery catheter insertion, assisting Pulmonary artery pressure and pulmonary artery wedge pressure monitoring Pulse assessment Pulse oximetry Relaxation and stress management techniques Respiration assessment Temperature assessment Venipuncture Weight measurement

Overview-Causes

Arteriosclerosis or atherosclerosis (80%) Inflammation (approximately 5% to 10%) Syphilis and other infections Trauma Genetic predisposition

Treatment-Activity

As tolerated Regular aerobic exercise

Treatment-Medications

Beta-adrenergic blockers, such as esmolol hydrochloride or labetalol hydrochloride, especially for patients considered to be at high risk; alternative agents, such as metoprolol succinate and propranolol hydrochloride Antihypertensives to control blood pressure; sodium nitroprusside to reduce arterial pressure in acute situations Analgesics, such as I.V. morphine sulfate, to prevent exacerbations with tachycardia and hypertension Aspirin Fluid and blood replacement, especially if rupture occurs

Nursing Considerations-Monitoring

Cardiac rhythm and hemodynamic status Vital signs, intake and output hourly, neurologic status, and pulse oximetry Respirations and breath sounds at least every hour Airway patency Arterial blood gas values, as ordered Daily weight Fluid and hydration status Nasogastric intubation for patency, amount, and type of drainage Laboratory studies Abdominal dressings Wound site for infection

Treatment-Surgery

Endovascular grafting or resection of large aneurysms or those that produce symptoms (see Endovascular grafting for repair of AAA) Bypass procedures for poor perfusion distal to the aneurysm Open repair of the ruptured aneurysm with a graft replacement

Assessment-History

Family history of AAA History of risk factors Asymptomatic until the aneurysm enlarges and compresses surrounding tissue manifested by early satiety, nausea, vomiting, or groin pain Syncope; sudden, severe, constant low back pain; flank, abdominal, or groin pain with expanding aneurysm After clot formation cessation of symptoms or abdominal pain because of bleeding into the peritoneum Most commonly asymptomatic

Overview-Pathophysiology

Focal weakness in the tunica media layer of the aorta due to degenerative changes allows the tunica intima and tunica adventitia layers to stretch outward. Increasing blood pressure within the aorta progressively weakens vessel walls and enlarges the aneurysm. Rupture occurs when the vessel wall tension exceeds the wall's ability to stretch

Assessment-Intact Aneurysm

Gnawing, generalized, steady abdominal pain Lower back pain unaffected by movement Gastric or abdominal fullness Sudden onset of severe abdominal pain or lumbar pain, with radiation to flank and groin Pulsating mass in the periumbilical or epigastric area Abdominal bruit

Assessment-Physical Findings

Gnawing, generalized, steady abdominal pain Lower back pain unaffected by movement Gastric or abdominal fullness Sudden onset of severe abdominal pain or lumbar pain, with radiation to flank and groin Pulsating mass in the periumbilical or epigastric area Abdominal bruit

Treatment-General

If the aneurysm is small and patient asymptomatic (size between 3.0 to 5.5 cm in diameter), watchful waiting Careful control of hypertension Continued surveillance Smoking cessation Control of atherosclerotic risk factors, such as hyperlipidemia Supplemental oxygen if rupture occurs

Nursing Considerations-For a Ruptured Aneurysm

Insert an I.V. line with at least a 14G needle to facilitate blood replacement. Obtain blood samples for laboratory tests as ordered. Maintain a patent airway and administer oxygen therapy to promote tissue perfusion based on oxygen saturation levels and arterial blood gas results. Obtain specimens for laboratory testing, including complete blood count, serum electrolytes, coagulation studies, liver function tests, and type and crossmatch as ordered. Give prescribed drugs, including fluid therapy, blood components, and agents to maintain hemodynamic function and relieve pain. Explain all treatments and activities to the patient, and provide support to the patient and family during this emergency situation.

Nursing Considerations-After Surgery

Perform neurovascular checks, assessing peripheral pulses for graft failure or occlusion. Watch for signs of bleeding retroperitoneally from the graft site. Assess hemodynamic status closely. Institute continuous cardiac monitoring and hemodynamic monitoring, as indicated. Evaluate hourly urine output. Obtain daily weights; check skin turgor and mucous membranes for signs and symptoms of fluid deficit. Administer I.V. fluids and medications, as ordered. Maintain I.V. patency and perform I.V. site care according to facility policy. Inspect abdominal dressing and incisional area for signs and symptoms of infection. Following an endovascular repair, inspect the groin area for signs and symptoms of infection and hematoma formation. Perform surgical site care according to facility policy. Assess NG tube location, patency, and drainage; maintain NG tube patency and perform NG tube care according to facility policy. Auscultate heart and lung sounds for changes; auscultate abdomen for evidence of bowel sounds. Maintain blood pressure in prescribed range with fluids and medications.

Overview-Complications

Rupture that causes hemorrhage and shock Dissection Thrombosis Postoperative cardiac, pulmonary, and renal complications Postoperative wound infection Death

Assessment-Ruptured Aneurysm

Severe, persistent abdominal and back pain for rupture into the peritoneal cavity GI bleeding with massive hematemesis and melena for rupture into the duodenum Mottled skin; poor distal perfusion Absent peripheral pulses distally Decreased level of consciousness Diaphoresis Hypotension Tachycardia Oliguria Distended abdomen Ecchymosis or hematoma in the abdominal, flank, or groin area Paraplegia if aneurysm rupture reduces blood flow to the spine Systolic bruit over the aorta Tenderness over the affected area

Treatment-Diet

Weight reduction, if appropriate Low-fat, low-salt, low-caffeine diet

Patient Teaching-General

elective versus emergent surgical repair and watchful waiting importance of monitoring and surveillance of the aneurysm via ultrasound or computed tomography every 6 to 12 months for changes in size; follow-up after endovascular repair with serial computed tomography scanning at 1, 6, and 12 months and then yearly methods for reduction of risk factors, such as lifestyle and dietary changes and smoking cessation details about elective surgery, if indicated, including the surgical procedure and expected postoperative care importance of taking all medications as prescribed and carrying a list of medications at all times, in case of an emergency signs and symptoms of rupture and the need to notify the practitioner immediately physical activity restrictions until medically cleared by a practitioner.

Nursing Considerations-Expected Outcomes

express feelings of increased comfort and decreased pain express feelings of decreased anxiety maintain adequate cardiac output maintain fluid balance maintain adequate ventilation maintain optimal mobility within the confines of the disorder maintain skin integrity maintain palpable pulses distal to the aneurysm site and hemodynamic stability exhibit adequate urine output.