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

• Triage Cat 4• BP 124/66 mmHg, P63/min• Temp 35.7C, SpO2 100%• Mild tenderness at the paraspinal area of T-

spine• Chest clear• Abdomen soft and no tenderness

CXR

Our management

• 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?

• Sprain back?• PID with radiculopathy?• Right leg DVT?• Other possibilities?• ……

Outcome

• 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

• 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 widening2. 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/portfolio-items/aortic-dissection-cxr-findings/

• http://www.wikiradiography.com/page/Calcium+Sign

• Thank you