Download 211 Abdominal Aortic Aneurysm notes

1
Abdominal Aortic Aneurysm
John Miller
Aortic aneurysm
 Abnormal dilation of a blood vessel
o Affects the aorta/peripheral arteries
o Forms due to weakness of arterial wall
o Thoracic or abdominal
 Abdominal is most common aortic aneurysm
 Classification
o Saccular: unilateral outpouching
o Fusiform: bilateral outpouching
o Dissecting: bilateral outpouching in which layers of vessel separate, creating a cavity
o False: wall ruptures and a blood clot is retained in an outpouching of tissue or there is a
connection between a vein and artery that does
Abdominal aortic aneurysm (AAA)
 Associated with arteriosclerosis and hypertension
 Can be asymptomatic
 Patient can present with abdominal mass, pain in mid-abdominal region or back.
 May rupture, causing hemorrhage, hypovolemic shock, and death
Aortic Aneurysm and Aortic Dissection
https://youtu.be/Bnoo5insrUQ?list=PLdVvae0BQcKztVN9VICTi25bXgmseXc0I
Risk Factors
 Arteriosclerosis
 Atherosclerosis
 Trauma
 Dissecting
o Men, 50-70, hypertensive
o Marfan’s syndrome
Diagnosis
 Computed tomography (CT) with contrast dye or MRI
 Angiography with contrast
 Ultrasound: Transesophageal echocardiogram (TEE)
 CXR
o Widened mediastinum
o Determine size, shape, and location of tear
 Lab
o Hemoglobin and hematocrit
Abdominal Aortic Aneurysm Imaging http://emedicine.medscape.com/article/416266-overview#a6
2
Complications
 Dissecting
o Life-threatening emergency
o A tear in the intima of the aorta allows blood to dissect or split the vessel wall
 Ischemia to vital areas
o Spinal cord weakness or paralysis, impotence
o Oliguria
o Ileus or colitis
o Prerenal failure from decreased blood flow from aneurysm, emboli, clamping during surgery,
decreased cardiac output.
 If CAD and / or COPD history then more prone to these postoperatively.
o Pneumonia
o Congestive heart failure
Assessment
 Most are asymptomatic.
 Palpable when 5 cm.
 Most common symptom: awareness of pulsating mass.
Dissection Assessment
 Abrupt excruciating pain (most common)
o Ripping, knife-like tearing
o Radiate to back, abdomen, groin, extremities, anterior chest
 Hypertension (common)
o Pale skin, apprehensive, sweating, diminished or absent pulses
 Other
o Paraplegia or hemiplegia
o Oliguria, hematuria
Treatment
 Check size every 6 months.
 Surgery for 4-6 cm and larger.
 Dissection
o Lower BP
 Vasodilator infusion (nitroprusside)
 Beta blockers to reduce contractility (metoprolol)
o Reduce pain
 Subsides when dissection stabilizes
o Blood transfusion
o Management of heart failure
o Emergency surgery
Beta Blockers: Metoprolol
 Class: Selective Beta1 Blocker, antihypertensive, antianginal, antidysrhythmic
 Therapeutic effect
o Decreased heart rate, negative chronotropic
o Decreased myocardial contractility, negative inotropic
o Decreased rate of conduction through AV node, negative dromotropic
 Uses for other conditions besides AAA
o Hypertension
o Angina, MI
o Dysrhythmias: Super Ventricular Tachycardia (SVT)
3
More Metoprolol
 Adverse effects
o Bradycardia: Use cautiously in diabetics where it can mask tachycardia, early sign of
hypoglycemia.
o Decreased cardiac output: Heart failure
o AV block
o Orthostatic hypotension
o Rebound myocardium excitation: Gradually discontinue over 1-2 weeks.
 Contraindications / Precautions
o Use cautiously in asthma, myasthenia gravis, depression, severe allergies.
 Interactions
o Calcium channel blockers intensify the effect.
o Concurrent use of other antihypertensive medications.
Hypertensive Crisis Medication: Nitroprusside
 Class: Centrally acting vasodilator
 Therapeutic effect: Direct vasodilation of arteries and veins, decreasing afterload and preload.
 Use: Hypertensive Crisis
 Adverse effects
o Excessive hypotension, shock
o Cyanide poisoning: Headache, drowsiness, may lead to cardiac arrest; reduced by giving
thiosulfate concurrently.
o Thiocyanate toxicity when more than three days: Delirium, psychosis
More Nitroprusside
 Contraindications/Precautions
o Pregnancy risk C
o Use cautiously
 Liver and kidney disease
 Fluid and electrolyte imbalance
 Interactions: Do not administer with other drugs in the line.
 Administration
o Protect container and tubing from light. Discard after 24 hours. Should be light brown in color.
o Vital signs and ECG should be constantly monitored.
Nursing care for abdominal aortic aneurysm without surgery
Reduce BP
o Semi-Fowlers
o Minimize unnecessary environment stress such as noise.
o Opioids for pain, tranquilizers if necessary
o Constant BP monitoring if IV antihypertensives used (arterial line)
o Monitor anxiety, vital signs.
o Observe for further tearing or rupture of aorta.
Nursing care: preoperative
 Open surgery last about 4 hours.
 Assess for lung, cardiac, and cerebrovascular disease.
4
Surgery for Dissection
 Indications
o Severe heart failure
o Leaking blood
o Occlusion of arteries to major organs
 Torn area is resected and replaced with synthetic graft (similar to AAA).
AAA Patient Education from Gore
https://www.goremedical.com/contentTypeDetail.jsp?action=contentDetail&N=8303+8239&R=12667098198
52
Endovascular surgery repair
 Endovascular stent grafts (EVSG)
o Synthetic graft is inserted via a groin incision.
o Graft sits inside the aneurysm.
Deployment of an Endovascular Graft in an Abdominal Aortic Aneurysm https://youtu.be/2qRP1_Kr5wQ
Open repair surgery
 Cardiopulmonary bypass
 Large abdominal incision, xyphoid to pubis symphysis
 Aorta is under the intestines, which have to be removed temporarily, increasing the risk for ileus.
 Aorta is clamped.
 Synthetic graft is place, with the aneurysm sac wrapped around it.
ABDOMINAL AORTIC ANEURYSM, Open Repair https://youtu.be/1ZGHilHQ0jA
Treatment Postoperative
 Intensive care
 Vital signs, urine output, hemodynamic pressures
 Anticoagulants
 Ventilator
 Monitor tissue and organ damage from long aortic clamping time.
o Skin
o Bowel
o Spinal cord
o Kidneys
 Pain managed with PCA or epidural.
Nursing Care Postoperative
 Diagnoses, outcomes, and interventions
o Risk for Ineffective Tissue Perfusion
o Risk for Injury
o Anxiety
 Continuity of care
o Pre and post surgery guidelines
o Referrals to home health agency, community health service as necessary
Abdominal Aortic Aneurysm Clinical Presentation http://emedicine.medscape.com/article/1979501-clinical
Abdominal Aortic Surgery | Ron Rolett's Story https://youtu.be/gTSbF3MJrUc