Nontraumatic thoracic aortic dissection: Difference between revisions

No edit summary
No edit summary
Line 14: Line 14:
**Elderly males with chronic hypertension
**Elderly males with chronic hypertension
**Atherosclerotic risk factors (smoking, hypertension, HLD, DM)
**Atherosclerotic risk factors (smoking, hypertension, HLD, DM)
===Classification (Stanford)===
===Classification (Stanford)===
*Type A - Involves any portion of ascending aorta  
*Type A - Involves any portion of ascending aorta  
Line 56: Line 57:
**Pulse deficit (2.7x)
**Pulse deficit (2.7x)
**[[Hypertension]] at time of presentation (49% of all cases<ref name="a">Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA. 2000; 283(7):897-903.</ref>)
**[[Hypertension]] at time of presentation (49% of all cases<ref name="a">Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA. 2000; 283(7):897-903.</ref>)
*Studies
**Enlarged aorta or widened mediastinum (3.4x)
**[[LVH]] on admission ECG (3.2x)


===Specific===
===Specific===
Line 127: Line 125:
===No Risk Factor Screening===
===No Risk Factor Screening===
*[[CXR]]
*[[CXR]]
**Abnormal in 90%  
**Abnormal in 90% (3.4x)
**Mediastinal widening (seen in 56-63%)  
**Mediastinal widening (seen in 56-63%)  
**Left sided pleural effusion (seen in 19%)  
**Left sided pleural effusion (seen in 19%)  
Line 144: Line 142:
===Other Findings===
===Other Findings===
*[[ECG]]
*[[ECG]]
**[[LVH]] on admission ECG (3.2x)
**Ischemia (esp inferior) - 15%  
**Ischemia (esp inferior) - 15%  
**Nonspec ST-T changes - 40%  
**Nonspec ST-T changes - 40%  

Revision as of 06:23, 13 July 2020

Not to be confused with traumatic aortic transection

Background

  • Most commonly seen in men 60-80 yrs old
  • Intimal tear with blood leaking into media
  • Mortality increases 1% per hour of symptoms when untreated
  • Diagnosis delayed > 24hr in 50% of cases
  • Bimodal age distribution

Classification (Stanford)

  • Type A - Involves any portion of ascending aorta
    • Requires surgery
  • Type B - Isolated to descending aorta
    • Primarily medical management with surgery consultation
Classification of aortic dissection
Image AoDissect DeBakey1.png AoDissect DeBakey2.png AoDissect DeBakey3.png
Percentage 60% 10–15% 25–30%
Type DeBakey I DeBakey II DeBakey III
Classification Stanford A (Proximal) Stanford B (Distal)

Clinical Features

General

  • Symptoms
    • Tearing/ripping pain (10.8x increased disease probability)
    • Migrating pain (7.6x)
    • Sudden chest pain (2.6x)
    • History of hypertension (1.5x)
  • Signs

Specific

Differential Diagnosis

Chest pain

Critical

Emergent

Nonemergent

Hypertension

Evaluation

Acute Aortic Dissection (AAD) Risk Score

A score 1 should be awarded for each of the 3 categories that contain at least one of the listed features

Predisposing conditions Pain features Physical findings

Chest, back, or abdominal pain described as:

  • Abrupt in onset/severe in intensity

AND

  • Ripping/tearing/sharp or stabbing quality
  • Evidence of perfusion deficit
    • Pulse deficit
    • Systolic BP differential
    • Focal neurological deficit (in conjunction with pain)
  • Murmur of aortic insufficiency (new or not known to be old and in conjunction with pain)
  • Hypotension of shock state
Score Category Prevalence
0 Low 6%
1 Intermediate 27%
>1 High 39%

No Risk Factor Screening

  • CXR
    • Abnormal in 90% (3.4x)
    • Mediastinal widening (seen in 56-63%)
    • Left sided pleural effusion (seen in 19%)
    • Widening of aortic contour (seen in 48%), displaced calcification (6mm), Calcium sign (look for white line of calcium within aortic knob and measure to outer edge of the aortic knob - distance greater than 0.5 cm is positive and > 1 cm is highly suspicious for dissection), aortic kinking, double density sign
CXR showing widened mediastinum and porminent aortic knob

Low-Intermediate (Based on AAD) Risk Rule-Out[3][4][5]

  • D-dimer for ADD score ≤ 1 (low or intermediate risk)

High Risk/Definitive

  • CT aortogram chest
    • Study of choice
    • Similar sensitivity/specificity to TEE and MRA
CT chest with contrast of thoracic aortic dissection.

Other Findings

  • ECG
    • LVH on admission ECG (3.2x)
    • Ischemia (esp inferior) - 15%
    • Nonspec ST-T changes - 40%
  • Bedside US
    • Can help in ruling in patients when AOFT is >4cm
    • Rule out pericardial effusion and tamponade, especially in hypotension, syncope, dyspnea
    • TEE has a sensitivity of 98% and 95% specific[6]
Type A Aortic Dissection[7]

Management

Lower wall tension by lowering BP (La Place T = P × r)

Control heart rate before blood pressure (Goal to keep HR <60 bpm and SBP 100-120)[8]
  • Important considerations
    • Right radial arterial line or right arm blood pressure will be the most accurate
    • Beta blockers are good first-line options, since they reduce heart rate and aortic wall tension
  1. Heart rate control (beta-blockers are first line)
    • Esmolol
      • Advantage of short half life, easily titratable
      • Bolus 0.1-0.5mg/kg over 1min; infuse 0.025-0.2mg/kg/min
      • Esmolol Drip Sheet
    • Labetalol - has both α and beta effects
      • Push dose - 10-20mg with repeat doses of 20-40mg q10min up to 300mg
      • Drip - Load 15-20mg IV, followed by 5mg/hr
    • Metoprolol
      • 5mg IV x 3; infuse at 2-5mg/hr
    • Diltiazem - Use if contraindications to beta-blockers
      • Loading 0.25mg/kg over 2–5 min, followed by a drip of 5mg/h
  2. Blood pressure control (vasodilators)
    • Only use if beta-blocker is ineffective
    • Do not use without a beta-blocker (must suppress reflex tachycardia - shear forces from increased HR)
    • Nicardipine/Clevidipine - consider following regimen for nicardipine:
      • 5mg/hr start, then titrate up by 2.5mg/hr every 10 min until goal
      • Once at goal, drop to 3mg/hr and re-titrate from there
      • May initially bolus 2mg IV[9]
    • Nitroprusside 0.3-0.5mcg/kg/min - Risk of cerebral blood vessel vasodilation and CN/Thiocynate toxicity
    • Fenoldopam
    • Enalapril
  3. Analgesia

Disposition

  • Admission to OR or ICU

Complications

  • AV Regurgitation/Insufficiency
    • CHF with diastolic murmur
  • Rupture
  • Vascular obstruction
    • Coronary: ACS
    • Carotid: CVA
    • Lumbar: Paraplegia

See Also

External Links

References

  1. ↑ 1.0 1.1 1.2 Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA. 2000; 283(7):897-903.
  2. ↑ Spittell PC, S et al. Clinical features and differential diagnosis of aortic dissection: experience with 236 cases (1980 through 1990) Mayo Clin Proc. 1993;68:642–51.
  3. ↑ Circulation. 2018 Jan 16;137(3):250-258. doi: 10.1161/CIRCULATIONAHA.117.029457. Epub 2017 Oct 13. Nazerian, et al. Diagnostic Accuracy of the Aortic Dissection Detection Risk Score Plus D-Dimer for Acute Aortic Syndromes: The ADvISED Prospective Multicenter Study.
  4. ↑ Asha SE et al. "A systematic review and meta-analysis of D-dimer as a rule out test for suspected acute aortic dissection." Annals of EM. 66;4;368-377Ocotber 2015.
  5. ↑ Shimony A, et al. Meta-analysis of usefulness of d-dimer to diagnose acute aortic dissection. Am J Cardiol. 2011; 107(8):1227-1234.
  6. ↑ Shiga T, Wajima Z, Apfel CC, Inoue T, Ohe Y. Diagnostic accuracy of transesophageal echocardiography, helical computed tomography, and magnetic resonance imaging for suspected thoracic aortic dissection: systematic review and meta-analysis. Arch Intern Med. 2006 Jul 10;166(13):1350-6.
  7. ↑ http://www.thepocusatlas.com/echocardiography-1
  8. ↑ Tsai TT, Nienaber CA, and Eagle KA. Acute Aortic Syndromes. Circulation. 2005;112:3802–3813
  9. ↑ Curran MP et al. Intravenous Nicardipine. Drugs 2006; 66(13): 1755-1782. http://emcrit.org/wp-content/uploads/2014/07/bolus-dose-nicardipine.pdf
Retrieved from "https://www.wikem.org/w/index.php?title=Nontraumatic_thoracic_aortic_dissection&oldid=262188"