The daily educational pearl – the Buerger’s test

So you think your patient has chronic limb arterial insufficiency.

You decide to the Buerger’s test

– with the patient supine, ask them to slowly lift the legs up (above the level of the right atrium) and look for colour change in the feet – if it occurs when the legs are elevated at an angle of less than 20 degrees it indicates severe ischaemia; in a limb with a normal circulation the toes stay pink, even when the limb is raised by 90 degrees

– the ask them to exercise the feet ~ 30 sec and look for colour change

– then ask them to sit up and measure the time to return of normal colour – if it’s > 20 sec, it is sign of ischaemia

The daily education pearl – aortic dissection treatment

Aortic dissection – treatment in ED

Early therapy for aortic dissection is CRITICAL and should be started while waiting for imaging.

Treatment has 3 goals:

1. analgesia
2. reduce BP
3. reduce the rate of rise in arterial pulse to reduce vascular wall shearing forces i.e.reduce HR


Reduce BP / HRtarget systolic BP 100-120 mmHg and HR < 60/min

A beta-blocker should be started before any vasodilators (to prevent the reflex tachycardia associated with vasodilators) – textbooks advise esmolol or labetalol but you can use metoprolol as well (selective Bblocker, so safe in patients with airway disease). If Bblockers are absolutely contraindicated, you can use a Calcium -channel blocker BUT a central-acting one (verapamil, diltiazem) and not a peripheral acting one (nifedipine, amlodipine)
Then start a vasodilator – nitroprusside or GTN.
If there is a BP difference between the 2 arms, treatment should be titrated to the higher BP, as they can get pseudohypotension due to an intimal flap obstructing the extremity.

If the patients are hypotensive, they should be fluid / blood resuscitated, but aim for sBP of 100mmHg, not higher. Pericardiocentesis can be a temporizing measure in the severely hypotensive patient, while awaiting transfer to theatre.

Type A aortic dissections (involving ascending aorta) require surgical treatment.
Type B aortic dissections (involving descending aorta only) can be managed medically in a tertiary hospital environment, with surgery only for those with ongoing pain, uncontrolled hypertension, occlusion of a major arterial trunk, rupture, or development of a localized aneurysm.

The daily educational pearl – aortic dissection

Aortic dissection

Risk factors:
– hypertension
– connective tissue disorders / vasculitis – Marfan’s, Ehlers-Danlos, giant cell arteritis
– congenital heart disease – bicuspid aortic valve

– cocaine / amphetamine use
– exertion
– trauma

– iatrogenic – intraaortic balloon pump insertion

Women with Marfan’s have increased risk of dissection during pregnancy.


– pain

* present in 90% cases

* sharp, “tearing”, “ripping”

* anterior chest (ascending aorta) / neck + jaw (aortic arch) / interscapular area (descending aorta) / lumbar area or abdomen (descending aorta below diaphragm)

* migration of the pain occurs with propagation of the dissection

– neurological symptoms (focal weakness / altered mental state – involvement of carotid / vertebral or spinal arteries) – 17% of cases

– syncope

– signs of lower limb ischaemia (involvement of iliac arteries)

Physical exam:

– severe hypertension refractory to medical therapy if renal arteries are involved (renin release)

– signs of pericardial tamponade – hypotension / tachycardia / raised JVP / muffled heart sounds

– aortic regurgitation – 32% of patients

– pulse deficits / radio-radial or radio-femoral delay / discrepancies in BP between limbs – only 30% sensitivity

– signs of ischaemia – CVA (carotid / vertebral a.) / limb / peripheral neuropathy (spinal a.)


– ECG – 3% cases dissect into a coronary artery, most commonly RCA – inferior STEMI on ECG

– CXR – abnormal in 80% cases; possible findings (think about the anatomy of the aorta!)
1. mediastinal widening (>8 cm measured at the level on the aortic knuckle)
2. left pleural effusion
3. apical pleural cap
4. depression left main bronchus
5. trachea deviated to the right
6. ETT deviated to the right
7. NGT deviated to the right
8. obliteration of the aortopulmonary window
9. right paratracheal stripe > 3 mm
10. “calcium sign” (intimal calcification separated from the outermost part of the aorta by > 5 mm)

– CT thoracic aortogram is the diagnostic test of choice – if your DD is dissection and PE, do a CTPA as the radiologists can look at the aortic lumen on a CTPA but can’t diagnose a PE on a CTA

– echo – can show dissection of ascending aorta