eMedicine Specialties > Emergency Medicine > Cardiovascular
Aneurysm, Abdominal: Treatment & Medication
Updated: Sep 8, 2009
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
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Treatment
Prehospital Care
- Prehospital care of patients having symptoms compatible with or suggestive of aortic aneurysm or dissection consists of assuring adequate breathing, maintaining oxygenation, treating shock, and obtaining useful information concerning history in order to expedite treatment on ED arrival. All patients with suspected aortic aneurysm should receive 100% oxygen along with continuous ECG and vital sign monitoring while en route to hospital. Large-bore IVs (14- or 16-gauge) should be inserted en route if possible.
- Establishing diagnosis in the field is usually difficult or impossible, but certain salient features of aortic aneurysm or dissection may be observed. Both can pose a threat to life if not quickly recognized and treated. Patients older than 50 years with sudden onset of abdominal pain should be presumed to have a ruptured abdominal aortic aneurysm (AAA) and should receive attentive airway management and vigorous fluid resuscitation, as indicated.
- Patient presentation during the prehospital phase of care differs depending on whether the aneurysm is acutely expanding or leaking or whether it involves the thoracic or abdominal aorta. Radio communication with the receiving hospital permits the medical control physician to direct care, and it facilitates selection of a capable destination hospital while permitting the ED to mobilize appropriate resources.
- The physician directing prehospital care should request transport to a facility capable of operative treatment of an aortic aneurysm in the rare event that the diagnosis can be suspected based on prehospital information.
- Use of military antishock trousers (MAST) to reverse shock due to ruptured AAA may seem beneficial, but it may actually be detrimental. While their application theoretically offers temporary stabilization by compressing the leaking AAA and expanding hematoma, an undesirable reduction in cardiac output also occurs. Expedient transport of patients who are unstable is a therapeutic imperative for those who are deteriorating.
Emergency Department Care
- Abdominal, back, or flank pain of sudden onset is characteristic of a rapidly expanding or ruptured abdominal aortic aneurysm (AAA). The diagnosis should be entertained whenever a patient older than 50 years presents with abdominal pain, particularly when pain is associated with syncope or signs of hemorrhagic shock.
- Examine patients suspected of having AAA for the presence of a pulsatile mass, which, if present, mandates immediate surgical intervention.
- Manage hemorrhagic shock with fluid resuscitation, blood transfusion, and immediate surgical consultation.
- Treatment for coagulopathy may be initiated in the ED for patients on warfarin or heparin.
- AAA rupture is believed to occur when the mechanical stress acting on the wall exceeds the strength of the wall tissue.
- Wall tension can be calculated using the Laplace Law for wall tension: P x R/W, where P = mean arterial pressure (MAP), R = radius of the vessel, and W = wall thickness of the vessel.
- AAA wall tension is a significant predictor of pending rupture. The actual tension in the AAA wall appears to be a more sensitive predictor of rupture than aneurysm diameter alone.
- For these reasons, the clinician may wish to achieve acute blood pressure control in patients with AAA and elevated blood pressure.
- Agents commonly used include antihypertensive agents and analgesics.
- Patients with leaking AAAs, if normotensive, do not require pharmacotherapy.
- In the setting of hypotension, reduction of blood pressure may be contraindicated.
- Initial therapeutic goals include elimination of pain and reduction of systolic blood pressure to 100-120 mm Hg, or to the lowest level commensurate with adequate vital organ (cardiac, cerebral, renal) perfusion.
- Whenever systolic hypertension is present, beta-blockers can be used to reduce arterial dP/dt.
- To prevent exacerbations in tachycardia and hypertension, treat patients with IV morphine sulfate. This reduces the force of cardiac contraction and the rate of rise of the aortic pressure (dP/dT) and may thus delay rupture.
Consultations
- Screening men beginning at 65 years reduces the mortality from rupture and is cost-effective.3 Open thoracic and abdominal aneurysm repair has a mortality rate of around 8%, with myocardial infarction being a frequent cause of death.3 Preoperative reduction of cardiac risk by cardiac investigations and beta-blockade may reduce this mortality rate. Autologous transfusion techniques, such as acute normovolemic hemodilution and interoperative cell salvage, reduce the need for allogeneic blood and the complications associated with open surgery. Minimally invasive endovascular repair is now possible for 40% of AAA and an increasing proportion of thoracic aneurysms.3,4
- The combination of screening, reduced preoperative risk, and new minimally invasive techniques extend aortic aneurysm treatment into an increasingly elderly population.
- Urgency of consultation is dictated by the stability of the patient. In patients who are stable but without symptoms, the diagnostic workup takes precedence. Consider consulting a radiologist to determine whether ultrasonography, CT scan, or MRI would be the most appropriate study.
- Follow-up with a vascular surgeon is warranted if the abdominal aorta exceeds 3 cm in diameter or if any segment is greater than 1.5 times the diameter of an adjacent section.
- Patients having abdominal aortic aneurysm (AAA) smaller than 4 cm in diameter require serial ultrasonography twice per year. If the diameter increases by more than 0.5 cm over 6 months, or if it exceeds 4 cm, surgical repair usually is warranted.
- Immediately consult a surgeon for symptomatic patients with AAA. If hemodynamically stable, imaging modalities may be considered following discussion with surgical consultant.
- In cases that involve patients who are unstable, immediately consult a surgeon. Then, notify anesthesia and operating room personnel. Bedside ultrasonography may be obtained while awaiting definitive treatment; however, it should not delay surgery. CT scanning is not appropriate in patients who are unstable.
Medication
The goals of pharmacotherapy are to reduce morbidity and to prevent complications.
Antihypertensives
Used to reduce arterial dP/dt. For acute reduction of arterial pressure, the potent vasodilator sodium nitroprusside is very effective. To reduce dP/dt acutely, administer an IV beta-blocker in incremental doses until a heart rate of 60-80 beats/min is attained. When beta-blockers are contraindicated, such as in second- or third-degree atrioventricular block, consider using calcium channel blockers.
Esmolol (Brevibloc)
Ultra–short-acting beta 2-blocker, particularly useful in patients with elevated arterial pressure, especially if surgery is planned. Can be discontinued abruptly if necessary. Normally used in conjunction with nitroprusside. May be useful as a means to test beta-blocker safety and tolerance in patients with history of obstructive pulmonary disease who are at uncertain risk for bronchospasm from beta-blockade. Elimination half-life is 9 min.
Adult
Loading dose infusion: 250-500 mcg/kg/min IV for 1 min, followed by a 4-min maintenance infusion of 50 mcg/kg/min; repeat loading dose and follow with maintenance infusion using increments of 50 mcg/kg/min (for 4 min) if therapeutic effects not observed in 5 min; repeat sequence up to 4 times prn
As desired BP is approached, omit loading infusion and reduce incremental dose in maintenance infusion from 50 mcg/kg/min to 25 mcg/kg/min or lower; may increase interval between titration steps from 5-10 min if desired
Pediatric
Not established
Aluminum salts, barbiturates, NSAIDs, penicillins, calcium salts, cholestyramine, and rifampin may decrease bioavailability and plasma levels of esmolol, possibly resulting in decreased pharmacologic effect; cardiotoxicity of esmolol may increase when administered concurrently with sparfloxacin, astemizole (recalled from US market), calcium channel blockers, quinidine, flecainide, and contraceptives; toxicity of esmolol increases when administered concurrently with digoxin, flecainide, acetaminophen, clonidine, epinephrine, nifedipine, prazosin, haloperidol, phenothiazines, and catecholamine-depleting agents
Documented hypersensitivity; uncompensated congestive heart failure; bradycardia; cardiogenic shock; A-V conduction abnormalities
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Beta-adrenergic blockers may mask signs and symptoms of acute hypoglycemia and clinical signs of hyperthyroidism; symptoms of hyperthyroidism, including thyroid storm, may worsen when medication is abruptly withdrawn; withdraw drug slowly and monitor patient closely
Labetalol (Normodyne, Trandate)
Blocks alpha-1 beta 1-, and beta 2-adrenergic receptor sites, decreasing BP.
Adult
20 mg (0.25 mg/kg for 80-kg patient) IV over 2 min initially, follow with 20-80 mg q10-15min until BP controlled
Maintenance dose: 2 mg/min infusion; titrate to 5-20 mg/min; not to exceed a total dose of 300 mg
Pediatric
Not established
Labetalol decreases effect of diuretics and increases toxicity of methotrexate, lithium, and salicylates; may diminish reflex tachycardia, resulting from nitroglycerin use, without interfering with hypotensive effects; cimetidine may increase labetalol blood levels; glutethimide may decrease labetalol effects by inducing microsomal enzymes
Documented hypersensitivity; cardiogenic shock; pulmonary edema; bradycardia; atrioventricular block; uncompensated congestive heart failure; reactive airway disease; severe bradycardia
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Caution in impaired hepatic function; discontinue therapy if signs of liver dysfunction present; in elderly patients, a lower response rate and higher incidence of toxicity may be observed
Propranolol (Inderal, Betachron E-R)
Class II antiarrhythmic nonselective beta-adrenergic receptor blocker. Has membrane-stabilizing activity and decreases automaticity of contractions. Propranolol is not suitable for emergency treatment of hypertension. Do not administer IV in hypertensive emergencies.
Adult
40-80 mg PO bid initially; increase as required to usual range of 160-320 mg/d; up to 640 mg/d may be required
Pediatric
0.5 mg/kg/d PO divided bid/qid and increase gradually q3-7d; usual dosage range is 2-4 mg/kg/d divided bid; not to exceed 2 mg/kg/d
Coadministration with aluminum salts, barbiturates, NSAIDs, penicillins, calcium salts, cholestyramine, and rifampin may decrease propranolol effects; calcium channel blockers, cimetidine, loop diuretics, and MAOIs may increase toxicity of propranolol; toxicity of hydralazine, haloperidol, benzodiazepines, and phenothiazines may increase with propranolol
Documented hypersensitivity; uncompensated congestive heart failure; bradycardia; cardiogenic shock; A-V conduction abnormalities
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Beta-adrenergic blockade may decrease signs of acute hypoglycemia and hyperthyroidism; abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm; withdraw drug slowly and monitor closely
Metoprolol (Lopressor)
Selective beta 1-adrenergic receptor blocker that decreases automaticity of contractions. During IV administration, carefully monitor BP, heart rate, and ECG. When considering conversion from IV to PO dosage forms, use ratio of 2.5 mg PO to 1 mg IV metoprolol.
Adult
100 mg/d PO qd or divided bid/tid initially; increase at 1-wk intervals prn up to a total of 450 mg/d prn
Pediatric
Not established
Aluminum salts, barbiturates, NSAIDs, penicillins, calcium salts, cholestyramine, and rifampin may decrease bioavailability and plasma levels of metoprolol, possibly resulting in decreased pharmacologic effects; toxicity of metoprolol may increase with coadministration of sparfloxacin, phenothiazines, astemizole (recalled from US market), calcium channel blockers, quinidine, flecainide, and contraceptives; metoprolol may increase toxicity of digoxin, flecainide, clonidine, epinephrine, nifedipine, prazosin, verapamil, and lidocaine
Documented hypersensitivity; uncompensated congestive heart failure; bradycardia; cardiogenic shock; A-V conduction abnormalities; asthma
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Beta-adrenergic blockade may reduce signs and symptoms of acute hypoglycemia and may decrease clinical signs of hyperthyroidism; abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm; monitor patient closely and withdraw the drug slowly; during IV administration, carefully monitor blood pressure, heart rate, and ECG
Nitroprusside (Nitropress)
Causes peripheral vasodilation by direct action on venous and arteriolar smooth muscle, thus reducing peripheral resistance. Commonly used IV because of its rapid onset and short duration of action. Easily titrated to desired effect. Nitroprusside is light sensitive and both bottle and tubing should be wrapped in aluminum foil. Prior to initiating nitroprusside, administer a beta-blocker to counteract physiologic response of reflex tachycardia that occurs when nitroprusside is used alone. This physiologic response will increase the shear forces against the aortic wall, thus increasing dP/dT. Objective is to keep heart rate between 60-80 bpm.
Adult
0.5-3 mcg/kg/min IV; rates >4 mcg/kg/min may lead to cyanide toxicity
Pediatric
Administer as in adults
None reported
Documented hypersensitivity; subaortic stenosis, idiopathic hypertrophic and atrial fibrillation or flutter
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Caution in increased intracranial pressure, hepatic failure, severe renal impairment, and hypothyroidism; in renal or hepatic insufficiency, nitroprusside levels may increase and can cause cyanide toxicity; sodium nitroprusside has the ability to lower blood pressure and thus should be used only in those patients with mean arterial pressures >70 mm Hg
Analgesics
Pain control is essential to quality patient care. It ensures patient comfort, promotes pulmonary toilet and prevent exacerbations in tachycardia and hypertension.
Morphine sulfate (Astramorph, Infumorph)
DOC for narcotic analgesia due to reliable and predictable effects, safety profile, and ease of reversibility with naloxone. Like fentanyl, morphine sulfate is easily titrated to desired level of pain control.
Morphine sulfate administered IV may be dosed in a number of ways and is commonly titrated until desired effect obtained.
Adult
Initial: 0.1 mg/kg IV/IM/SC
Maintenance: 5-20 mg/70 kg q4h IV/IM/SC
Pediatric
0.1-0.2 mg/kg/dose IV/IM/SC q2-4h prn
Phenothiazines may antagonize analgesic effects of opiate agonists; tricyclic antidepressants, MAOIs, and other CNS depressants may potentiate adverse effects of morphine
Documented hypersensitivity; hypotension; potentially compromised airway where establishing rapid airway control would be difficult
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
Caution in hypotension, respiratory depression, nausea, emesis, constipation, and urinary retention; caution in atrial flutter and other supraventricular tachycardias; has vagolytic action and may increase ventricular response rate
More on Aneurysm, Abdominal |
| Overview: Aneurysm, Abdominal |
| Differential Diagnoses & Workup: Aneurysm, Abdominal |
 Treatment & Medication: Aneurysm, Abdominal |
| Follow-up: Aneurysm, Abdominal |
| Multimedia: Aneurysm, Abdominal |
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References
[Guideline] U.S. Preventive Services Task Force. Screening for abdominal aortic aneurysm: recommendation statement. Ann Intern Med. Feb 1 2005;142(3):198-202. [Medline]. [Full Text].
Blaivas M, Theodoro D. Frequency of incomplete abdominal aorta visualization by emergency department bedside ultrasound. Acad Emerg Med. Jan 2004;11(1):103-5. [Medline].
Daly KJ, Torella F, Ashleigh R, McCollum CN. Screening, diagnosis and advances in aortic aneurysm surgery. Gerontology. Nov-Dec 2004;50(6):349-59. [Medline].
Reichart M, Geelkerken RH, Huisman AB, et al. Ruptured abdominal aortic aneurysm: endovascular repair is feasible in 40% of patients. Eur J Vasc Endovasc Surg. Nov 2003;26(5):479-86. [Medline].
AbuRahma AF, Woodruff BA, Lucente FC, et al. Factors affecting survival of patients with ruptured abdominal aortic aneurysm in a West Virginia community. Surg Gynecol Obstet. May 1991;172(5):377-82. [Medline].
Adamson AS, Darke SG. Aneurysm repair in patients presenting with distal embolization. Am J Surg. Feb 1992;163(2):273. [Medline].
Banerjee A. Atypical manifestations of ruptured abdominal aortic aneurysms. Postgrad Med J. Jan 1993;69(807):6-11. [Medline].
Bengtsson H, Bergqvist D, Ekberg O, et al. Expansion pattern and risk of rupture of abdominal aortic aneurysms that were not operated on. Eur J Surg. Sep 1993;159(9):461-7. [Medline].
Blanchard JF, Armenian HK, Friesen PP. Risk factors for abdominal aortic aneurysm: results of a case-control study. Am J Epidemiol. Mar 15 2000;151(6):575-83. [Medline].
Bower TC, Cherry KJ Jr, Pairolero PC. Unusual manifestations of abdominal aortic aneurysms. Surg Clin North Am. Aug 1989;69(4):745-54. [Medline].
Durham JR, Hackworth CA, Tober JC, et al. Magnetic resonance angiography in the preoperative evaluation of abdominal aortic aneurysms. Am J Surg. Aug 1993;166(2):173-7; discussion 177-8. [Medline].
Ernst CB. Abdominal aortic aneurysm. N Engl J Med. Apr 22 1993;328(16):1167-72. [Medline].
Frauenfelder T, Wildermuth S, Marincek B, Boehm T. Nontraumatic emergent abdominal vascular conditions: advantages of multi-detector row CT and three-dimensional imaging. Radiographics. Mar-Apr 2004;24(2):481-96. [Medline].
Kiell CS, Ernst CB. Advances in management of abdominal aortic aneurysm. Adv Surg. 1993;26:73-98. [Medline].
LaRoy LL, Cormier PJ, Matalon TA, et al. Imaging of abdominal aortic aneurysms. AJR Am J Roentgenol. Apr 1989;152(4):785-92. [Medline].
Lee WA, Carter JW, Upchurch G, Seeger JM, Huber TS. Perioperative outcomes after open and endovascular repair of intact abdominal aortic aneurysms in the United States during 2001. J Vasc Surg. Mar 2004;39(3):491-6. [Medline].
Loughran CF. A review of the plain abdominal radiograph in acute rupture of abdominal aortic aneurysms. Clin Radiol. Jul 1986;37(4):383-7. [Medline].
Lyon M, Brannam L, Ciamillo L, Blaivas M. False positive abdominal aortic aneurysm on bedside emergency ultrasound. J Emerg Med. Feb 2004;26(2):193-6. [Medline].
Marston WA, Ahlquist R, Johnson G Jr, et al. Misdiagnosis of ruptured abdominal aortic aneurysms. J Vasc Surg. Jul 1992;16(1):17-22. [Medline].
National Center for Health Statistics. Vital statistics of the United States. 1991. [Full Text].
Pavone P, Di Cesare E, Di Renzi P, et al. Abdominal aortic aneurysm evaluation: comparison of US, CT, MRI, and angiography. Magn Reson Imaging. 1990;8(3):199-204. [Medline].
Peppelenbosch N, Yilmaz N, van Marrewijk C, et al. Emergency treatment of acute symptomatic or ruptured abdominal aortic aneurysm. Outcome of a prospective intent-to-treat by EVAR protocol. Eur J Vasc Endovasc Surg. Sep 2003;26(3):303-10. [Medline].
Raghavan ML, Vorp DA, Federle MP, et al. Wall stress distribution on three-dimensionally reconstructed models of human abdominal aortic aneurysm. J Vasc Surg. Apr 2000;31(4):760-9. [Medline].
Reddy DJ, Shepard AD, Evans JR, et al. Management of infected aortoiliac aneurysms. Arch Surg. Jul 1991;126(7):873-8; discussion 878-9. [Medline].
Salen P, Melanson S, Buro D. ED screening to identify abdominal aortic aneurysms in asymptomatic geriatric patients. Am J Emerg Med. Mar 2003;21(2):133-5. [Medline].
Stanford W, Rooholamini SA, Galvin JR. Ultrafast computed tomography in the diagnosis of aortic aneurysms and dissections. J Thorac Imaging. Oct 1990;5(4):32-9. [Medline].
Tefera G, Carr SC, Turnipseed WD. Endovascular aortic repair or minimal incision aortic surgery: Which procedure to choose for treatment of high-risk aneurysms?. Surgery. Oct 2004;136(4):748-53. [Medline].
Vohra R, Reid D, Groome J, et al. Long-term survival in patients undergoing resection of abdominal aortic aneurysm. Ann Vasc Surg. Sep 1990;4(5):460-5. [Medline].
Further Reading
Keywords
abdominal aneurysm, abdominal aortic aneurysm, AAA, mycotic aneurysm, abscess formation, atherosclerosis, smoking, chronic obstructive pulmonary disease, COPD, hypertension, syncope, shock, cyanosis, sudden cardiovascular collapse, peripheral atherosclerotic vascular disease, Marfan syndrome, Ehlers-Danlos syndrome, collagen vascular diseases, mycotic aneurysm, claudication, pulsatile abdominal mass, abdominal bruit, aortic rupture
