Medical School Lesson Plan – Acute Aortic Dissection

Picture the scene…

You see a 73 old man in majors who has had a sudden onset of severe chest pain, which has now gone. He is sitting reading the paper and in majors.

Learning Objective

To learn about the diagnosis and management of acute aortic dissection in the ED.

Listen to David Carr’s talk on acute aortic dissection.

Read and make notes on this article from the European Society of Cardiology.

This part of the teaching session should be lead by an experienced clinican. The cases provided are merely examples and if possible the learners should be encouraged to discuss patients they have seen in their clinical practice.

You see a 73 old man in majors who has had a sudden onset of severe chest pain, which has now gone. He is sitting reading the paper. He has a normal examination and his ECG normal. His vital signs are normal apart from a blood presssure of 190/100.

Simple tests such as the ECG and CXR can help lower the probability of STEMI, pneumothorax or other lung pathology. The chest X-ray will also give you an idea about if there is mediastinal widening, although normal CXR does not rule out aortic dissection if clinical suspicion is high.

Many ED clinician would suggest that if you consider aortic dissection is a possible diagnosis, then the only test to rule it out is a CT aortagram. The caveat to this is that if you have less clinical experience aortic dissection will likely always be part of your differential in the patient with chest pain.

Here you really need to talk to a senior and ask them to see the patient with you. Then you’ll get any idea of their theshold for organising further testing.

You don’t really need anymore information. It is all there in the history as David Carr said in his SMACC talk. This is (yet) another example of the history being the most important thing in your clinical encounter.

A 68 year old lady presents with sudden onset neck pain and chest pain. She looks unwell, with distended neck veins and a blood pressure of 90/50. Her ECG shows inferior ST elevation. She is in severe pain, and tells you that her pain was maximal at time of onset. The nurse in charge tells you she is going call the cath lab…

1. 2. What test would you want at the bedside? 3 Which other team needs to be involved?

This isn’t straightforward. You have an ECG that shows inferior myocardial infarction, but the history could be that of an aortic dissection. In these cases you need senior input early, as well as involvement of the recvelant specialties in your hospital. Even if you think this isn’t coronary occlusion causing STEMI I’d call the cardiologist and tell them about the patient and ask them to join me in resus (preferably with an Echo machine).

Although inferior ECG changes could represent right ventricular infarction and a drop in pre load (causing the low blood pressure), here the suspicion would be that a type A dissection could be causing bleeding into the percardium and cardiac tamponade.

An urgent echocardiogram looking for a pericardial effusion with “tamponade physiology” – Diastolic right ventricular collapse (high specificity); Systolic right atrial collapse (earliest sign); Plethoric inferior vena cava with minimal respiratory variation (high sensitivity) and exaggerated respiratory cycle changes in mitral and tricuspid valve in-flow velocities as a surrogate for pulsus paradoxus.

As soon as a Type A dissection is confirmed you will need to contact your local cardiothoracic service. This will differ depending on your hospital and it is important to discuss that now. How would you make that happen? Where is the phone number for the cardioothoracic team (or is it via the switchboard)? Who organises the transfer if the patient needs to be takenb to another hospital?

Type A aortic dissection is a time-critical problem, and mortality increases with the time to surgery, so early involvement is the key. One of the key attributes of an effective Emergency Physican is the ability to “make things happen” – no more so than in this case.

In this session we have learned about the clinical assessment of the patient with a potential acute aortic dissection.

Remember to consider the diagnosis in anyone with “chest pain plus one”, ie chest pain and another system involved: headache; limb ischaemia, etc.

It aortic dissection is a potential diagnosis then a CT aortogram is the only test that can rule it out – discuss these patients with your ED senior colleague.

Remember that difference between the Type A and Type B dissection – the management for these differs and early recognition of the Type A is vital if the patient is to have a chance of survival.

In order to embed today’s learning further, reflect on what you have learnt and record in your portfolio whether it has had any impact (or is expected to have any impact) on your performance and practice.

Was this a topic that you were confident you knew already? Which parts were new to you? Were there elements that you will use on your next clinical shift.

Dscuss this session with your colleagues – were there people who missed it who you can share the highlights with?



Cite this article as: Sanjay Ramamoorthy, "Medical School Lesson Plan – Acute Aortic Dissection," in St.Emlyn's, September 22, 2020, https://www.stemlynsblog.org/medical-school-lesson-plan-acute-aortic-dissection/.

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