JCM
4th June 2014
History
• M/28 Chinese
• Police Cadet
• History of back pain treated conservatively
2011
• Severe upper back pain after firing a pistol in
Cadet School
• No SOB, no weakness, no radiation
Examination
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Triage Cat 4
BP 124/66 mmHg, P63/min
Temp 35.7C, SpO2 100%
Mild tenderness at the paraspinal area of Tspine
• Chest clear
• Abdomen soft and no tenderness
CXR
Our management
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CXR: no pneumothorax, pneumomediastinum
Ketorolac IMI given
Pain decreased after IMI
Advised to avoid physical exercise
Discharged with NSAIDs and sick leave for 1
day
4 days later
• Noticed right leg pain and numbness
• Feeling coldness of right leg
• Patient worried about side effects related to
the previous IM Ketorolac
• Circulation normal
• No neurological deficit
• Lower limb power full
X-ray T-L spine
DDx?
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Sprain back?
PID with radiculopathy?
Right leg DVT?
Other possibilities?
……
Outcome
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Admitted to Ortho QMH in view of pain
Suspected T9 collapse at lateral X-ray by Ortho
Private MRI spine referred
Noticed type B aortic dissection on MRI
Both leg warm and abdomen soft
Vascular team consulted and agreed to
takeover
CT Aortogram
CT Aortogram
CT Aortogram
CT Aortogram
• Type B aortic dissection from distal aortic arch
down to right iliacs/ CFA
• No coronary artery stenosis
• Both kidneys perfused symmetrically
• False lumen compressing true lumen leading
to decreased blood flow to both lower limbs
Management
• BP controlled with beta-blockers
• Pain well controlled
• Discharged home D13 after admission
• 2 months later, endovascular stenting was
done in QMH in view of young age and
involvement of the right iliacs/ CFA
Long term management
• Follow up with contrast CT in 6 months
• BP control with home BP monitoring
• Advised light duty and to avoid competitive
sports/ collision
Acute aortic dissection (AAD)
• A potentially catastrophic disease that
remains difficult to diagnose in the emergency
department
• Circulation 2010
– Mortality 40% for immediate death
– 1% per hour for incremental death thereafter
– 20% for perioperative death
– 50% to 70% reported survival rate after initial
surgery
Epidemiology
• True incidence is unknown
• Population-based prevalence studies have
estimated the incidence to be about 3 cases
per 100000 people per year
• Higher incidence in men (65%) and with
increasing age
• Significant medicolegal issues surrounding
missed diagnosis of AAD
• Common misdiagnoses
– Acute coronary syndrome (19%)
– Musculoskeletal pain (20%)
– Pneumonia/ pulmonary embolism (20%)
– Pericarditis (12%)
– Gastrointestinal pain (9%)
– Other causes (20%)
• Consider the diagnosis of AAD in situations of
– Sudden severe chest pain
– Accompanying visceral symptoms (nausea,
vomiting, pallor, diaphoretic)
– Normal/ minimally abnormal ECG findings
– Inappropriate reliance on classic features
Classification
Clinical assessment in the ED
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Risk factors
Presentations
Physical findings
End-organ presentations
Risk factors
Presentations
• Sudden-onset severe chest pain (91%)
• Visceral symptoms – pallor, vomiting, diaphoresis
(78%)
• Intermittent pain (75%)
• Radiation to back/ neck/ arms/ jaw (69%)
• Pleuritic/ positional pain (44%)
• Pyrexia (22%)
• Syncope (9%)
• Tearing quality (3%)…
CMPA case review series of missed AAD (n = 32 patients)
• Poor reliance on the presence or absence of
these features
• High level of suspicion is needed
Physical findings
• Peripheral pulses in the upper extremities/ blood
pressure differentials
• New aortic regurgitation murmurs
• Complications of acute aortic regurgitations
– Congestive heart failure, cardiogenic shock, pericardial
tamponade,
• Mass compression effects on adjacent structures
– SVC, sympathetic chain, recurrent laryngeal nerve,
tracheobronchial tree, esophagus…
• Unreliable and frequently absent in patients
with AAD
End-organ presentations
• Cardiovascular: AR and related disorders, pulse deficits,
BP differentials, syncope, MI, CHF, cardiogenic shock,
conduction abnormalities…
• Syncope: cardiovascular, neurologic
• Neurologic: intracranial, brainstem, spinal cord, lower
extremities
• Ears/ nose/ throat: mass effects on trachea, esophagus,
RLN, sympathetic chain
• Respiratory: mass effects on tracheobronchial tree,
hemorrhage into lung tissue/ pleural space, pleural
effusions
• GI: mesenteric ischemia, aortoenteric fistula
Diagnostic tests
• ECG (non-specific change)
• Laboratory markers (currently no sensitive/
specific test)
– Soluble elastin fragments, smooth muscle myosin
heavy chain, WBC, hsCRP, fibrinogen, D-dimer
Diagnostic images
• Chest X-ray
– Abnormal aortic contour, mediastinal widening,
pleural effusion, displacement of intimal
calcifications, abnormal aortic knob, displacement
of trachea or NG tube deviation to the right…
1. Mediastinal widening
2. Widening of aortic contour
Calcium sign
Diagnostic images (continued)
• CT
• Transesophageal echocardiography
• MRI
Circulation 2010
Management of type B AD
• Mainly Medical treatment in form of BP control
– Maintain PR <60/min by Beta blockers and SBP <120mmHg
[Class I; level C]
– 1 month survival 89%
– 1 year survival 84%
– But poor long term outcome: Mortality 30-50% at 5 year
• Surgical Intervention
– Indicated in complicated AD: malperfusion, rupture, rapid
expansion esp false lumen, extension, severe pain, failed to
control BP [Class I; level B]
– Open Surgery: High mortality in the past
– Endovascular Stenting: Maybe more superior but lacking
evidence on long term survival
Circulation 2010
Endovascular Interventions (TEVAR)
Follow up
• Close follow-up visits
• Long-term medical therapy with beta-blockers
• Serial imaging
– 1, 3, 6 and 12 months post-dissection
– Annually thereafter if stable
Summary for AAD
• Rare but potentially catastrophic
• Presentation and initial assessment findings are
always non-specific
• High index of suspicion is needed
• CT is the most common diagnostic modality
initially used
• Initial management with BP, heart rate and pain
control important
• Subsequent definitive surgical consultation
• Failure to consider AAD in these situations
(and document risk assessments accordingly)
can lead to clinically adverse outcomes for
patients and medicolegal liability for
physicians
References
• Upadhye S, Schiff K. Acute aortic dissection in the
emergency department: diagnostic challenges and
evidence-based management. Emerg Med Clin North
Am. 2012 May;30(2):307-27, viii.
• De Leon Ayala IA, Chen YF. Acute aortic dissection: an
update. Kaohsiung J Med Sci. 2012 Jun;28(6):299-305.
• Hiratazka LF, Bakris GL, Beckman JA, et al. 2010
ACCF/AHA/AATS/ACR/ASA/SCA/SCAI/SIR/STS/SVM
guidelines for the diagnosis and management of
patients with thoracic aortic disease. Circulation
2010;121:e266-369.
References (continued)
• http://www.medinterestgroup.com/portfolioitems/aortic-dissection-cxr-findings/
• http://www.wikiradiography.com/page/Calciu
m+Sign
• Thank you