The St.Emlyn's Podcast

Ep 3 - Understanding diagnostics 1. SNout SpIn and Probability. St.Emlyn's

A podcast discussing sensitivity and specificity of diagnostic tests and how we can use this in our everyday medical care of patients. 

This article from the Centre for Evidence Based Medicine is also useful. 

Ep 4 - Diagnostics 2. Beyond simple yes vs no diagnostics. St.Emlyn's

Dear all,

It would appear that the organ member was correct and we cannot be certain about the organ pipes. Apparently there are doubts about whether they are safe or need replacing. 

We will once again turn to Dr Beardsell and Prof. Carley to see if there is anything more that we can do. As I am due to allocate funds for repairs to musical instruments this year then we must ensure that these are spent wisely. 

If there is a less than 2% chance of failure we will wait. If there is a greater than 50% chance of failure then we should spend the money. 

The situation is uncertain and we need help.

I have the honour to be et. etc. etc.

The Choirmaster at St.Emlyn's

Ep 5 - Understanding diagnostics 3. Why prevalence helps us stay in practice

Iain and Simon tackle the effect of prevalence on diagnostic performance. Mrs Trellis of North Wales makes a return appearance to discuss the delicate issues of sensitivity and Rick Body joins us by mail to raise concerns about the difficulties of missing patients with myocardial disease.

Listen and enjoy, visit the blog site and keep in touch.

Don't forget to subscribe to the podcast via iTunes, to subscribe to the blog site and to like us on facebook.

vb

S

Ep - 11 Understanding Troponin Part 1

Do you remember when it took three days to 'rule in' or 'rule out' an acute myocardial infarction (AMI)?  When I was a medical student doing my first clinical attachments, I remember doing ward rounds on the CCU seeing patients with suspected AMI.  The way they were managed is a million miles from what we do now.  Back then, patients would have serial ECGs and then be admitted for cardiac enzyme evaluation over the course of the next 3 days.  We'd measure CK, AST and LDH.  'CK' was the so-called 'early marker', which would rise early after the start of an AMI.  Today we use CK as a marker of skeletal muscle damage (e.g. rhabdomyolysis).  AST and LDH (today we think of these as liver function tests, I know) were the 'late markers' - and by late I really mean late - we might see a rise on days 2 and 3.

Could you imagine for a second, in today's world, ruling out AMI because their CK and LFTs were normal?  It's completely unthinkable.  That's how much cardiac troponin has changed our practice.  We rely on it so completely to diagnose AMI.  And yet, it's one of the most misunderstood tests in medicine.  Given how much we use it, I guess we feel that we all should know lots about this test.  But doctors still have so many questions.  Here are just a few:

• What is cardiac troponin?
• Why is it a marker of AMI?
• What else causes a raised troponin and how?
• Should we be doing troponins at 3 hours, 6 hours, 12 hours?  What's the difference and what's the evidence?
• What is a 'delta troponin'?
• What do you need to 'rule in' AMI?
• How do you use cardiac troponin in patients with renal failure?

This is just a brief list.  With the research I do in this area and my experience developing protocols/guidelines, people get in touch to ask questions like this quite a lot.  There are loads of questions that people ask - but there are lots of themes in common.  We thought it was about time we produced a handy run down in the true spirit of #FOAMed.

Take a listen to Part 1 of our troponin podcast.  While Simon and Iain have been prolifically churning out spectacular stuff for some time now, this is my debut on the St. Emlyn's podcast.  I really enjoyed talking about troponin with Iain - and I hope we covered some useful stuff.

We'll cover more in part 2, when we'll move on to discussing high sensitivity troponins, what they are, how to use them and how to speak the troponin lingo.  Please get in touch if there's anything we haven't covered that you'd like us to, or if there's anything you'd like us to elaborate on some more!

Rick

Ep 12 - Intro to EM: The patient with headache

We've all had headaches, but not often severe enough to prompt us to seek help in an Emergency Department.

In our practice 10% of patients who do present to the ED  with a primary presentation of headache will have serious pathology and our job as Emergency Physicians is to work out who these are. Key to this is actively ruling out the life-threatening and life-changing diagnoses:

• Subarachnoid Haemorrhage
• Meningitis
• Tumours and Space Occupying Lesions
• Temporal Arteritis

Listen to Simon and Iain discuss how to approach these patients here

Further Resources

Headaches at Life in the Fast Lane - a great summary from the LiTFL crew

NICE Guidelines (NCG150) - diagnosis and management of headaches; there's a flowchart and some red flags although you could read the St Emlyn's summary here!

Headache from the Flipped EM Classroom

Ep 13 - Intro to EM: The patient with shortness of breath

Breathless patients are a challenge in the ED. Shortness of breath can be a frightening presenting complaint for both patients and doctors. As always, think about the possible life threatening causes and actively rule them out. For breathless patients think especially about:

• Pneumonia
• Asthma/COPD
• Pulmonary Embolism
• Acute left ventricular failure
• Pneumothorax

 

Breathless Patients Podcast

In this podcast Iain and Simon discuss their approach to breathless patients in the ED which we hope will provide you with a good starting point.

 For those of you who are more visual learners here is the video recorded a few years ago for SEMEP featuring our very own Iain Beardsell.

http://vimeo.com/35310564

 

Take Home Points

• Oxygen should be used in the patient with shortness of breath and the patient monitored closely. Hypoxia kills
• Always rule out life threatening causes first
• These patients are sick - do not be afraid to ask advice from a senior colleague early
• Look for clues - you don't have to wait until the penultimate page of the story to solve the mystery.

What have you learned about breathless patients?

 Oxygen - or no oxygen??
Oxygen administration is rarely a problem in the immediate and acute setting - and can save lives. So yes, when you first approach a patient who is short of breath, get that oxygen on while you make your assessment then think about the finer points of respiratory failure afterwards. 

Where do I begin?
A focused history, including asking the patient about previous conditions and whether they know what's going on!
And then - initial assessment and examination including vital signs (especially respiratory rate), looking for clues as to the underlying cause of their breathlessness, remembering the five common causes. 

What treatments might be useful?
A small fluid bolus might help and carries relatively little risk; think about the need for nebulised bronchodilators for patients with asthma or COPD, and remember that antibiotics given early to patients with sepsis save lives.
If the patient has pain we should definitely treat that too.

Which investigations might help me find out more?

• A chest x-ray is often useful in patients who are short of breath; your ED seniors might be able to use bedside ultrasound to further ascertain the underlying pathology, so get help early!
• ECGs are often useful in these patients
• Blood gases can also provide lots of useful information - think carefully about whether you need arterial gases and if so, please use local anaesthetic.
• If nothing makes sense - get a blood sugar, remembering that metabolic disease may cause an acidosis, presenting with an increased respiratory rate (although not often true dyspnoea).
• And GET SENIOR HELP (including getting your seniors to assess you for those all-important workplace-based assessments; definitely start those early)

Other resources

Chest Radiographs

One of the key investigations in patients with shortness of breath is the humble chest radiograph. There are some phenomenal FOAM resources for interpretation of CXRs (along with other XRs) at Radiology Masterclass. Well worth bookmarking for your ED shifts (but do ask a senior if you're unsure).

Chest X-Ray Anatomy  -  Chest X-Ray Abnormalities  -  Chest X-Ray Systematic Approach

Blood Gases

Think! Do you really need an ABG? If the answer is yes, please use local anaesthetic! Your patients will thank you...

Further Reading on Shortness of Breath

The Flipped EM Classroom - Shortness of Breath (with further links).

Natalie May

 

Ep 15 - Understanding Troponin Part 2

Recently we published part one of our series on cardiac troponins.  If you haven't checked it out yet, you can find it here.    In the second part, we're going to take a look at high sensitivity troponins and some of the more advanced areas around understanding cardiac troponin and its use in practice.  We'll give you a quick run down on the troponin lingo - the language you need to be able to speak in order to fully understand how to use high sensitivity troponin in your practice, including terms like the limit of blank, limit of detection, co-efficient of variation and 99th percentile.

We'll also ask whether Joe Lex had a point when he stirred up controversy around these assays with this legendary tweet:

What if we called it "low specificity troponin" instead of "high sensitivity troponin?" Would that knock some sense into people?

— Joe Lex (@JoeLex5) October 9, 2012

So, check out the associated BLOG POST here and listen to the podcast. There is more on diagnostics and troponin to come very soon.

Hope you enjoy! Please keep the feedback, questions and comments coming. As always, we'd love to hear from you.

Rick

DOI: Much of my research work involves HsT. To help with this I have received reagents from companies who make HsT assays, but I not received any other financial benefit or gifts in kind as part of my work and have no financial ties to any companies.

Ep 20 - Understanding Troponin Part 3: The NICE guidance.

Rick and Iain explore how the latest guidance about the use of high sensitivity troponin was developed and how far we can be assured that it is evidence based.

The NICE guidance is available here. http://www.nice.org.uk/guidance/dg15

vb

S

Ep 37 - Karim Brohi at LTC (LTC 2014)

Karim Brohi joins the St.Emlyn's team at the London Trauma Conference to talk on vascular injury and arterial dissection. A whole range of diagnoses that you should not miss, but which is easy to miss.

Tricky!

Check out the blog post that accompanies this podcast here.

S

Ep 47 - Barbra Backus on Risk scores in Acute Coronary syndromes

Barbra Backus joins Rick Body to discuss the origin, development and future of risk scores for ED patients with possible acute coronary syndromes. Two researchers at the top of their game, and  authors of the HEART and MACS scores.

 

vb

 

S

Ep 128 - Can we use diagnostic probability to guide treatment thresholds in ACS with Charlie Reynard and Rick Body

This is a really important concept developed by Charlie Reynard and Rick Body here in Manchester. There is an accompanying paper in the EMJ that you can read via this link https://emj.bmj.com/content/34/12/A870 

This concept could radically change how we make probabilistic prescribing decisions in the ED. Have a listen and look out for a blog post on St Emlyn's soon.

Ep 129 - January 2019 Round Up

The latest blog posts, ideas and thoughts from the St Emlyn's podcast. This month with Simon Carley and Rick Body,

Ep 132 - Aortic Emergencies with George Wills at #stemlynsLIVE

Back in late 2018 we gathered in Manchester for the inaugural #stemlynsLIVE conference. Our friend Dr George Wills gave a great talk on Aortic Emergencies.

All emergency physicians know that it's all to easy to miss an aortic catastrophe. Listen to George's wisdom on common pitfalls and top tips to make you a better emergency clinician.

vb

S

Also check out these excellent #FOAMed resources.

• Subscribe to the blog (look top right for the link)
• Subscribe to our PODCAST on iTunes
• Follow us on twitter @stemlyns
• PLEASE Like us on Facebook
• Find out more about the St.Emlyn’s team

Ep 133 - February 2019 Round Up

Our regular monthly round up of the best of the blog from Feb 2019.

Ep 134 - March 2019 Round Up

Here’s our regular monthly round up of the best of the blog from March 2019

 

Ep 135 - April 2019 Round Up

Here is the latest from the St Emlyn's team

 

Ep 143 - The Future of Diagnostics with Rick Body

Prof. Rick Body is an internationally recognised expert in diagnostic testing. In this podcast he takes us through diagnostics today and also the near future which may change almost everything. 

You can read more and see the slides/video at http://www.stemlynsblog.com

Ep 202 - May 2022 Round Up

Our monthly round up of all from the St Emlyn's blog. We discuss pathways into emergency care research, pad positioning in cardioversion of AF and possible gender differences in the presciption of TXA in trauma.

We also chat about travel in Lithuania, memories of defibrillating with hand held paddles and Simon's recent forst infection with COVID.

We mention a post on Lyme disease which you can read here (especially if you live near the New Forest...)

 

Ep 206 - October 2022 Round Up

In our new regular slot of the middle Monday of the month we're delighted to bring you the highlights from the St Emlyn's blog this month.,

Iain and Simon chat about batching in EDs, Ossilation in decision making and a whole lot more about trauma (chest drains, extrication, sex and TXA and rib fixation).

Please do like and subscribe and keep an eye out for our new sister website St Emlyn's Medical School and it's podcast series coming soon. 

Ep 213 - Sensitivity and Specificity (CAN 10)

The latest CAN is one of our brand-new 'revision editions' -- brief podcasts aimed at covering the essentials of critical appraisal for medical students and junior doctors preparing for exams.

With the help of Gregory Yates, an academic doctor based in Manchester, this episode introduces two core concepts: sensitivity and specificity. These are two ways of thinking about the accuracy of a diagnostic test. Knowing the sensitivity and specificity of an investigation will give you a decent idea of how it should be used in the emergency department.

Sensitivity (Sn) describes the chance that a test will be positive if your patient has the condition you're testing for. Some people call it the 'true positive rate' or alternatively the positivity in disease (PID) rate. If you need a hand remembering it, you can always remember that PID is a sensitive issue.

 

Meanwhile, specificity (Sp) considers the chance of a test being negative if the patient doesn't have the condition you're testing for. It's the 'true negative rate' or alternatively the negativity in health (NIH) rate. There are times when we particularly need a test to have a high sensitivity. This is generally when we want to be particularly confident that a test accurately identifies everyone with the relevant condition because we really don't want to miss it. We need a high sensitivity to rule out disease. (Sn-uff it out). At other times, we need to be confident that a patient with a positive test actually has the disease - for example, if the treatment is unpleasant or involves exposing patients to risk. In that case, we want a high specificity to rule in disease. (Sp-in it in).

 

In this CAN, we use D-Dimer as an example of a very sensitive investigation: it’s positive in nearly 100% of cases of venous thromboembolism. Specificity describes the likelihood that the test will be negative if your patient does not have the disease. We use HbA1c as an example of a highly specific investigation: it’s rarely used in the emergency department, but if it’s elevated, we can be almost certain that the patient is diabetic. HbA1c is almost never (<1%) raised in non-diabetics.

The trouble is, many patients with a positive D-Dimer do not have a venous clot, and the majority of diabetics will have a normal HbA1c! No test is perfect, and we discuss how emergency physicians weigh up sensitivity and specificity when choosing which investigations are the best "fit" for clinical decision-making. By the end of this CAN, you will be ready to do the same -- in your exams, and on the shop floor.

 

Ep 215 - March 2023 Monthly Round Up

Our monthly podcast round up from St Emlyn's Blog. This month Simon and Iain discuss the prehospital use of troponin measurement in the assessment of patients with chest pain and the use of AI in medicine, as well as an update about St Emlyn's WILD.

Please do like and subscribe