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Aneurysm, Thoracic: Treatment & Medication
Updated: Sep 28, 2009
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Treatment
Prehospital Care
- In patients with symptoms suggestive of thoracic aortic aneurysm (TAA), prehospital care should consist of ensuring adequate airway and breathing, providing oxygen via a nonrebreather mask, placing 2 large-bore intravenous lines, and providing continuous cardiac monitoring.
- Patients who are unstable (often those with a ruptured aneurysm or dissection) may require airway protection, mechanical ventilation, and aggressive fluid resuscitation. Timely communication between prehospital care providers and the receiving hospital is important in ensuring that the proper resources are available and brought to bear rapidly.
Emergency Department Care
- Initial stabilization includes the following:
- Placing 2 large-bore intravenous lines, administering 100% oxygen, and providing a cardiac monitor
- Monitoring urine output
- Consider alternate diagnoses. Until the diagnosis of thoracic aortic aneurysm (TAA) is established, be vigilant for other causes of symptoms, such as myocardial infarction (MI), aortic insufficiency, CHF, or pulmonary embolus.
- Provide aggressive blood pressure control. Beta-blockers and nitrates are commonly used.3
- For patients who are hemodynamically unstable, provide the following:
- Aggressive fluid resuscitation (including blood products)
- Placing an arterial line in the right radial artery (or in the left radial artery, if the systolic blood pressure on the left is higher), especially in patients who may have dissection or in those who are receiving intravenous nitroprusside and/or esmolol
- Correction of coagulopathy
- Immediate surgical consultation
Consultations
- Immediately consult with a cardiac surgeon (for ascending aorta or arch) or with a vascular surgeon (for descending aorta) for patients who are hemodynamically unstable or for patients with symptoms of a thoracic aneurysm. Anesthesia and operating room personnel need to be contacted in cases where emergent operative procedures are indicated.
- Consult with a vascular surgeon or a cardiac surgeon and a radiologist to determine the optimal studies for assessing the anatomy of the thoracic aneurysm.
Medication
The goal of medical therapy is to reduce the pulse pressure (dP/dt) within the aorta. Reducing the heart rate, the blood pressure (BP), pain, and anxiety are the mainstays of therapy.
Antihypertensive agents
These agents are used to reduce arterial pressure. Short-acting IV beta blockade and nitrates are very effective in reducing the dP/dt, especially in the ascending aorta. Consider calcium channel blockade in patients with contraindications to beta blockade.
Esmolol (Brevibloc)
Ultra–short-acting beta1-blocker particularly useful in patients with labile arterial pressure because it can be abruptly discontinued if necessary. Typically 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 of bronchospasm from beta blockade. Elimination half-life is 9 min. The objective is a target heart rate of 55-65 bpm.
Adult
Loading dose infusion: 250-500 mcg/kg IV over 1 min, followed by a 4-min maintenance infusion of 50 mcg/kg/min; if desired clinical effects are not observed, a repeat loading dose may be administered, followed by a 4-min infusion at 100 mcg/kg/min IV; 2 more repeat loading doses may be administered if desired effect is still not attained, increasing each subsequent 4-min infusion dose by 50 mcg/kg/min IV; the overall pattern would yield the following:
Cycle 1: Load 250-500 mcg/kg IV over 1 min, 50 mcg/kg/min IV over 4 min
Cycle 2: Load 250-500 mcg/kg IV over 1 min, 100 mcg/kg/min IV over 4 min
Cycle 3: Load 250-500 mcg/kg IV over 1 min, 150 mcg/kg/min IV over 4 min
Cycle 4: Load 250-500 mcg/kg IV over 1 min, 200 mcg/kg/min IV over 4 min
When 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, possibly resulting in decreased pharmacologic effect; sparfloxacin, astemizole (recalled from US market), calcium channel blockers, quinidine, flecainide, and contraceptives may increase cardiotoxicity; digoxin, flecainide, acetaminophen, clonidine, epinephrine, nifedipine, prazosin, haloperidol, phenothiazines, and catecholamine-depleting agents may increase toxicity
Documented hypersensitivity; uncompensated CHF; bradycardia; cardiogenic shock; AV 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 withdrawn abruptly (withdraw drug slowly and monitor closely)
Labetalol (Normodyne, Trandate)
Blocks alpha-, beta1-, and beta2-adrenergic receptor sites, decreasing BP.
Adult
Initial dose: 20 mg (0.25 mg/kg for 80-kg adult) IV over 2 min; follow with 20-80 mg IV q10-15min until BP is controlled
Maintenance dose: 2 mg/min IV continuous infusion; titrate up to 5-20 mg/min; not to exceed total dose of 300 mg
Pediatric
Not established
Decreases effects of diuretics and increases toxicity of methotrexate, lithium, and salicylates; may diminish reflex tachycardia associated with nitroglycerin use without interfering with hypotensive effects; cimetidine may increase blood levels; glutethimide may decrease effects by inducing microsomal enzymes
Documented hypersensitivity; cardiogenic shock; AV block; uncompensated CHF; pulmonary edema; bradycardia; reactive airway disease
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 occur; lower response rate and higher incidence of toxicity may be observed in elderly patients
Metoprolol (Lopressor)
Selective beta1-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
5 mg IV q2min, up to 3 times
100 mg/d PO qd or divided bid/tid initially; increase at 1-wk intervals prn; not to exceed 450 mg/d
Pediatric
Not established
Aluminum salts, barbiturates, NSAIDs, penicillins, calcium salts, cholestyramine, and rifampin may decrease bioavailability and plasma levels, possibly resulting in decreased pharmacologic effects; sparfloxacin, phenothiazines, astemizole (recalled from US market), calcium channel blockers, quinidine, flecainide, and contraceptives may increase toxicity; may increase toxicity of digoxin, flecainide, clonidine, epinephrine, nifedipine, prazosin, verapamil, and lidocaine
Documented hypersensitivity; uncompensated CHF; cardiogenic shock; bradycardia; AV 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 reduce signs and symptoms of acute hypoglycemia and may decrease clinical signs of hyperthyroidism; abrupt withdrawal may exacerbate symptoms of hyperthyroidism, including thyroid storm (withdraw drug slowly and monitor closely); during IV administration, carefully monitor BP, heart rate, and ECG
Propranolol (Inderal, Betachron E-R)
Class II antiarrhythmic nonselective beta-adrenergic receptor blocker. Has membrane-stabilizing activity and decreases automaticity of contractions. Not a first-line agent in the treatment of hypertensive emergencies. Do not administer IV in hypertensive emergencies.
Adult
40-80 mg PO bid initially; increase to usual range of 160-320 mg/d PO prn; up to 640 mg/d PO may be required
Pediatric
0.5 mg/kg/d PO divided bid/qid; increase gradually q3-7d; usual dosage range is 2-4 mg/kg/d PO divided bid; not to exceed 16 mg/kg/d
Aluminum salts, barbiturates, NSAIDs, penicillins, calcium salts, cholestyramine, and rifampin may decrease effects; calcium channel blockers, cimetidine, loop diuretics, and MAOIs may increase toxicity; may increase toxicity of hydralazine, haloperidol, benzodiazepines, and phenothiazines
Documented hypersensitivity; uncompensated CHF; bradycardia; cardiogenic shock; AV 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); caution in patients with reactive airway disease; consider arterial line for close BP monitoring
Nitroprusside (Nipride, Nitropress)
Causes peripheral vasodilation by direct action on venous and arteriolar smooth muscle, thus reducing peripheral resistance. Commonly used IV because of rapid onset and short duration of action. Easily titratable to reach desired effect. Light sensitive; both bottle and tubing should be wrapped in aluminum foil. Prior to initiating, administer beta-blocker to counteract physiologic response of reflex tachycardia that occurs when nitroprusside is used alone. This physiologic response increases shear forces against aortic wall, thus increasing dP/dT.
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; 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, levels may increase and can cause cyanide toxicity; has ability to lower BP and thus should be used only in patients with mean arterial pressures >70 mm Hg
Analgesics
Analgesics are used to control pain and to decrease sympathetic tone.
Morphine sulfate (Astramorph, Infumorph)
DOC for narcotic analgesia because of 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. If administered IV, may be dosed in a number of ways; commonly titrated until desired effect obtained.
Adult
Initial dose: 0.1-0.3 mg/kg IV/IM/SC
Maintenance dose: 5-20 mg IV/IM/SC q4h for a 70-kg adult
Pediatric
0.1-0.2 mg/kg IV/IM/SC q2-4h prn
Phenothiazines may antagonize analgesic effects; tricyclic antidepressants, MAOIs, and other CNS depressants may potentiate adverse effects
Documented hypersensitivity; hypotension; potentially compromised airway in which 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
Avoid 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, Thoracic |
| Overview: Aneurysm, Thoracic |
| Differential Diagnoses & Workup: Aneurysm, Thoracic |
 Treatment & Medication: Aneurysm, Thoracic |
| Follow-up: Aneurysm, Thoracic |
| Multimedia: Aneurysm, Thoracic |
| References |
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References
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Further Reading
Keywords
thoracic aneurysm, aortic aneurysm, thoracic aortic aneurysm, TAA, abdominal aortic aneurysm, cystic medial necrosis, atherosclerosis, Marfan syndrome, Marfan's syndrome, Ehlers-Danlos syndrome
