Acute Kidney Injury (& Hyperkalaemia)...

Whilst revising this I couldn't stop myself seeing how easy it is to turn into a part B question, the stem could begin with an ecg and ask you to describe the changes and give the diagnosis. Then ask you to list causes and describe the treatments. Alternatively you could be given a blood gas result including a sodium, potassium and glucose with an Addissonian picture and be asked to list what changes you would look for on the ECG, then to describe your management. Worst case scenario could even be to define an Acute Kidney Injury. Given it lends itself so well it is little wonder that it is a previous part B question!

Acute Kidney Injury:

Definition:

Stage 1: 
- creatinine rise >26 from baseline over 48 hrs
- creatinine rise x1.5 from baseline over 1 week
- Urine output <0.5 ml/kg/hr for 6 hrs

Stage 2:
- creat 2-3x baseline
- urine output <0.5ml/kg/hr for 12 hrs

Stage 3:
- creat >3x baseline
- <0.3ml/kg/hr for 24 hrs or anuria

The Causes are summarised in the following diagram borrowed from the wonderful Sketchy medicine

Investigation in the ED can help pin down the cause: protein on urine dip suggests glomerular disease, blood on dip think TINS (Trauma/ infection/ neoplasm/ Stones). However by far the commonest cause is pre-renal ie poor perfusion (sepsis/ hypovolaemia/ etc).

Management in the ED involves: catheter and hourly urine output, IVI bolus and response monitoring, treat the cause!

Hyperkalaemia

The most significant complication of AKI from an ED perspective is the potential for an increased serum potassium, as this can by imminently life threatening!

• Mild: 5.5-6 mmol/l
• Moderate 6.1-6.9 mmol/l
• Severe >7 mmol/l

See raised K+ think ECG:

• Tall t-waves (easy)
• short QT
• prolonged PR
• wide QRS
• flat p waves
• VT  (may be pulsed)

Treatment:

1. Calcium Chloride 10mls 10% IV - cardioprotective
2. Insulin - shifts potassium intracellular (remember to give with glucose!)
3. Salbutamol neb.

Clever Marks:

Marks may be available for recognising an addisonian crisis (hyponatraemia, hyperkalaemia and hypoglycaemia) and treatments including hydrocortisone.

Bad to Worse... SIRS, Sepsis and Shock...

The bread and butter of Resus, there are certain things you will see at work time and time again and this is one of the them. However it is not always something we manage as well as we should. Here is a three step approach to recognising sepsis:

Step 1:

The first concept you have to get your head round is the the Systemic Inflammatory Response Syndrome (SIRs)... Which requires two or more of the following:

• Hr >90
• RR >20
• Temp >38.3, <36
• WCC >12 or <4

SIRs does not mean sepsis but it does mean the patient is unwell (seems obvious), however it just means the body is reacting to an insult. This could be trauma/ post surgery/ PE/ infection/ autoimmune. I find my self documenting explicitly the sirs criteria present before my diagnosis for all my patients and this makes it easier to remember the exact criteria.

Step 2:

Does the patient have an infection or do you suspect they might? This deliberately includes the suspicion of infection as you may not have proof straight away but this should not delay treatment. It obviously requires you to have examined the patient and consider basic investigation. If the answer is yes the patient has sepsis.

Step 3:

Is there end organ dysfunction? Easy ones to quickly measure are renal function (urine output) and brain function (GCS).  If the answer is yes the patient has severe sepsis. You can also measure liver function (INR), Lactate, etc.

The final thing to know is the definition of SHOCK- which is inadequate tissue perfusion given end organ dysfunction and this clearly overlaps with our severe sepsis definition. The magic number to remember is a MAP <65.

What Next?

Its all good and well recognising SIRs/ Sepsis/ Shock but actually that is only half the story as we need to be able to treat these patients as well. Guidance exists on this from the surviving sepsis campaign: http://www.sccm.org/Documents/SSC-Guidelines.pdf

This can be summarised into initial management steps and some physiological targets:

Decussation is the key to the infamous Brown Seqard...

Well this one always gives me a headache... spinal cord syndromes! No matter how hard I try I can't keep these in my head, however the video podcasts http://emergencymedicineireland.com/anatomy-and-em/ always make it easy to refresh my knowledge:

AFEM 06.1 - anterior cord syndrome
AFEM 06.2 - central cord syndrome
AFEM 06.3 - brown seqard

This is a pet topic made for exams as it includes anatomy and specific clinical findings matched to that anatomy, it can be linked to a variety of clinical cases/ images. It could also quite easily be tied into a question about c-spine clearance, management of suspected spinal injury or SCIWORA.

My summary of Brown Seqard is below (the colour scheme and concept are borrowed from AFEM):

Can't Pee...

Another of the CT3 additional presentations:

Urinary retention is a fairly common presentation, but it is not the most glamorous of topics, there is however a CEM standard for its management and it easily could make an SAQ.

There is a nice summary article on the BMJ website http://www.bmj.com/content/318/7188/921

Question:

A 72 year old man presents with increasing lower abdominal pain and the inability to pass urine for the past 24 hours. He is in obvious distress and is tachycardic and hypertensive, a bladder scan is performed and shows in excess of 800mls. You successfully pass a urethral catheter and the patient is quickly relieved.

1) List 3 differentials for this man's problem. (3)

2) What clinical features would suggest a history of prostatism? (2)

3) Following insertion of a urethral catheter list three things you should document. (3)

4) Give two features that would require hospital admission. (2)

Blood Pressure is a GP thing right?

So we spend a lot of our time worrying about shock/ hypotension and are probably better at putting people's blood pressure up (white coat hypertension). Just occasionally though you will meet somebody whose blood pressure is too high and needs to come down.

What constitutes a hypertensive emergency? The section in the BNF is rather good for this and was my go to resource for part A.

Important numbers are 180/ or /110, the second step is to decide if there is end organ dysfunction:

1. Hypertensive encephalopathy
2. Acute LVF
3. Acute MI
4. Aortic Dissection
5. Intracranial Haemorrhage
6. AKI
7. Eclampsia

The presence of any of the above is hypertensive emergency.

Without them it is hypertensive urgency.

Remember BP = CO x SvR

Treatment options mostly cause some form of vasodilatation: sodium nitroprusside/ labetalol/ nitrates.

Another review of a course...

So I recently attended the Bromley Mcem Part B course (http://www.mcemcourses.org).

The course itself is two days in the clinical education centre of the Princess Royal hospital in Orpington. It includes 4 practice papers (with one sent out before the course) and lectures on some common topics that come up frequently.

The course faculty admit that they cannot cover the whole syllabus but they do try to flag up common things. It also includes so good tips on exam technique and how to approach the paper. I'm am not going to go into detail on what they say as I don't want to steal their content. However I will say I found the course useful and came away feeling better prepared to tackle the paper.

Another useful thing they encourage is to mark other people's papers to recognise how to make the examiner's life easier.

Their website's free resources include cases of the week, these make good practice questions.

All in all I would definitely recommend the course.

Decompression, Drain or not to drain...

Tension pneumothorax... every one knows how and where to decompress (https://www.youtube.com/watch?v=PblI70wkpjg - you only have to watch the first three minutes but I recommend the whole episode).

However what if it is a primary pneumothorax, measured at 3cm and no features of a tension? Fortunately the BTS are there to help: http://www.brit-thoracic.org.uk/Portals/0/Guidelines/PleuralDiseaseGuidelines/Pleural%20Guideline%202010/Pleural%20disease%202010%20pneumothorax.pdf

The Takeaway points can be summarised in the following flow chart and diagram

Another nice easy stem would be to describe the anatomical landmarks for the safety triangle:

Question...

(this should be easy after reading the above)

A skinny 24 your old presents with shortness of breath and reduced air entry on auscultation of the left chest.

1) Describe your management of this condition.

2) What features would suggest a tension pneumothorax?

3) Give the land marks of the "safe ares" for chest drain insertion, and why is it "safe"?

4) List three predisposing factors for this condition.

5) What advice would you give before discharge?

College Standards...

Found another wonderful little document on the college website (actually discovered it quite by accident preparing for a CBD on urinary retention). It summarises the standards set by CEM for the timings of certain investigations and interventions for various conditions, including:

• Asthma
• Dislocated shoulders
• Feverish Children
• Fractured Neck of femur
• Head injury in Adults
• Hand Injury
• Mental Health
• Pain
• Paracetamol OD
• Radiology
• Recording vital signs in Majors and Resus
• Renal Colic
• Retention of Urine
• Safeguarding Children
• Sepsis and Meningitis in Children
• Severe Sepsis and Septic Shock in adults
• Spontaneous Pneumothorax in Adults

This has to be mandatory reading for PART B, it is like a one stop shop for writing SAQs! These are basic standards that lend themselves so well to examination.

The document above: Download the clinical standards

Then CEM guidance in general: http://www.collemergencymed.ac.uk/Shop-Floor/Clinical%20Guidelines/

Bazzet's Formula and QTC...

So this will be the first of a few posts on ecgs (this will be a new label on the blog). I am going to start with one of the things I hate... calculating the QTC.

Without devolving into a massive rant knowing how to calculate this is relatively straight forward and there are some good apps that can do it for you, rather than doing the math itself. It is also one of the weaknesses of the automated ecg interpretations. However it is also of great clinical importance i.e.. sudden cardiac death and has been a previous question.

Hopefully the following is not new to you:

I don't think I can do a better job of explaining than the following: http://lifeinthefastlane.com/ecg-library/basics/qt_interval/

If that doesn't clear things up the only thing I can suggest is to work it out every time and ecg is thrust under your nose - if you work anywhere like where I do this will mean after one shift you will be an expert!

ACS Risk scoring

All scoring systems make good SAQs as there are different things to ask such as components, what carries more weight and asking why is it useful.

Both TIMI and GRACE help predict the mortality/ further consequences in patients with suspected or confirmed ACS. In the ED perhaps they are most useful for helping to support a safe discharge of a person with trop negative chest pain. After all a STEMI will be referred regardless of their GRACE score.

Nice recommend the GRACE score which is worked out via normograms and therefore usually computer generated after the inputs are entered. It is also worth knowing the Khilip classification of heart failure (an easy SAQ: outline the Khilip classification of heart failure)

1. No heart failure
2. Mild- moderate heart failure
3. Pulmonary oedema
4. Cardiogenic Shock

The Timi Score has come up in previous questions and lends it self very well as one point is assigned to each feature making it easy it calculate. The risks range from 5% for 1 point, up to 41% for 6/7 points.

Question:

A 54 year old male smoker presents with an episode of central chest pain whilst walking his dog. He felt sweaty, clammy and nauseous at the time.

1) What are the indications on ECG for PCI? (3)

2) What initial treatments should be given in the ED? (3)

3) List three  further features of history you would like to enable you to calculate his risk of death and name the scoring system you would use. (4)

DVLA and illness.

So you've seen a patient, sorted them out and now it's time for discharge... they take their car keys out of their pocket and then you remember does the DVLA have something to say about their diagnosis?

Never fear, the college has a nice little summary of conditions that lead to restrictions on driving.

CEM summary of DVLA fitness to drive medical standards

Conditions restricting driving:

Things that do

1. Seizure- 6 months
2. LOC with high risk factors- 6 months unless cause identified
3. Cough syncope- 6 months
4. CVA - 1 month
5. Angina- driving must stop with symptoms at rest/ emotion/ at wheel
6. Arrhythmia - stop driving if arrhythmia incapacitates
7. Diabetes- only if awareness of hypoglycaemia is lost
8. Attacks of disabling giddiness - stop driving

Things that don't

1. Hypertension
2. Single episode of syncope.

Copycat or Inspired By...

Inspired by the previous post about sketchy medicine I have scanned in one of my revision "post-it" notes that I have up around my desk. It's my summary of common organisms causing illness in adults...

Brilliant little find...

I stumbled upon this little gem of a website with fantastic cartoon summaries of various topics... perfect for a quick revision bite...

http://sketchymedicine.com

Also some of the images are for sale on etsy.

Here's an example for toxidromes:

Another Post about Burns...

Found this article on BMJ whilst trying to find an learning module on burns (for CT3 curriculum), contains an SAQ style question.

http://www.bmj.com/content/341/bmj.c4485

DIY is dangerous...

What to say about this one... it was a bansaw.

Calculations for Kids...

An essential part of the CT3 - Paediatric Block, most likely to appear in part C, but could easily be part of a stem in Part B.

WETFLAG Calculation

W        Weight           1-12months (0.5 x age in  months) + 4

                                    1-5yrs (2 x age in yrs) + 8

                                    6-12yrs (3 x age in yrs) + 7

E          Electricity        4 Joules / Kg/ biphasic

T          Tube ETT      Internal Diameter   (age/4 + 4) =    --- mm

Length           Oropharangeal Tube (age /2 +12) = -- cm

                                                Nasopharyngeal tube (age /2+ 15) = --- cm 

F          Fluids             Medical / cardiac arrest – 20 ml/ kg

                        Trauma cases initial Bolus 10 ml/ kg, then 2^nd 10 ml /kg

L          Lorazepam   0.1 mg / Kg  IV/ IO

A         Adrenaline    0.1 ml/kg of 1:10, 000 = 10mcg/kg

G         Glucose         2ml / kg of 10% dextrose 

Utilised on both APLS and EPLS - again especially relevant to CT3 year.

For a day to day basis there are some excellent apps for the smart phone enabled. Certainly for those with an iPhone I would recommend Paeds ED.

• After inputing the gender plus known weight or age it gives you resus data plus key doses of common medications.  Invaluable at 2am when a sick kid rocks up and your brain is not at it's mathematical peak.

Paracetamol:

By far the commonest paediatric prescription I write. Dosed at 15mg/kg

The easy way:

= weight (kg) x 10 + half again                 

for 30 Kg = 30 x 10 = 300 + 150 = 450 mg

Baby on Board

The majority of pregnancies don't need the ED, but sometimes things don't go to plan, therefore a working knowledge of physiology in pregnancy and certain presentations are common MCEM questions.

For Part A

For Part B

Pre-Eclampsia affects around 5-6% of pregnancies. It is a triad of...

1. Hypertension 
2. Proteinuria
3. Oedema

1-2% of patients with pre-eclampsia will develop eclampsia. Eclampsia is marked by the development of seizures.

For Pre-eclampsia:

• Obstetric input
• Consider left lateral position - see physiological changes in pregnancy
• Control BP - labetalol/ hydralazine
• Limit fluid input.
• Consider magnesium
• Delivery is the definitive management. Notably pre-eclampsia can develop for up to several weeks after delivery!

For Eclampsia:

• ABC!
• Magnesium 4g IV over 5-10 mins to treat seizures.

Further Reading:

• http://www.rcog.org.uk/files/rcog-corp/GTG56.pdf 
• http://www.nice.org.uk/nicemedia/live/13098/50416/50416.pdf

A Quiz For Fun...

Anybody care to take a guess at what the foreign body is? No prizes I am afraid, but will definitely earn respect. Post your answers in the comments below... The answer will be revealed in due course.

Differing Blood Pressures.

1) Give FOUR causes of a widened mediastinum. (2 marks)
2) List THREE features (other than a widened mediastinum) that can be found on CXR with dissection of thoracic aorta. (3 marks)
3) Identify FOUR risk factors for aortic dissection. (2 marks)
4) Outline your management of Aortic dissection in the ED (3 marks)

Feel free to post your answers in the comments below.

C-Spine X-rays

Neck pain post RTC is a common clinical presentation and can form an easy exam question. Anything from interpreting an X-ray to questions on guidelines for choosing who/ how to image could come up.

http://www.radiologymasterclass.co.uk/tutorials/musculoskeletal/x-ray_trauma_spinal/x-ray_c-spine_normal.html - Is a good guide to interpretting C-spine X-rays.

The ABCD approach of ATLS is also an accepted approach.

Imaging (XR) should be performed in the following (CEM recommendations):

• GCS <15
• Neurological deficit/ parasthesia
• Hypotension or abnormal respirations
• Neck pain >7/10
• Patients with neck pain + one of the following high risk factors
• fall >1m / 5 stairs
• axial loading
• RTC >60mph/ rollover/ ejection
• Bicycle collision
• Age >65
• Injury >48 hr previously
• Representation with the same injury
• Known vertebral disease
• Patients with a high risk factor and injury above clavicle/ painful thoracic injury even if no neck pain.

The exceptions being if there are no high risk factors and any of the following low risk factors then an assessment of range of movement can be made...

• Simple rear-end RTC
• Sitting in ED
• Mobile at any time
• Delayed onset of pain
• Absence of midline tenderness

CT When:

• GCS <13
• Intubated
• Inadequate XR or uncertainty
• If CT for head injury or multiregion trauma

CEM Guidline pdf, Practical guide

B is For... Books and a tip for Burns management

There aren't many books specifically for MCEM

For Part A:

Question books - never underestimate the benefit of practicing MCQ's

• Get Through MCEM Part A: MCQs (Get Through Series) - AKA the Red One
• Divided into sections on specific areas covered by the exam such as anatomy, physiology,   pharmacology, microbiology, etc.
• As well as 3 mock papers.
• Gives answers and good depth of explanations.
• Recommended by most and is of similar standard to the exam itself.

• MCEM Part A Practice Questions (Oxbridge Medica's Revision Series) - AKA the Green One
• Again divided into key topics for each chapter, the chapter sizes seem weighted to reflect the exam.
• What I like the most is that answers are on the reverse of the same page as the question. This means you can use the book in short spells, or even in the rare event of spare time on the shop floor.
• This one seems harder to get hold of via the internet (amazon/ ebay

• Practice Papers for MCEM Part A - AKA the Blue One
• 8 practice papers back to back.
• Seems to be similar standard to the exam, my scores prior to taking the paper reflected my final score in the paper.
• The smallest book in terms of physical size but given its structure it doesn't lend itself to "quick" bites. Better to sit and practice as mock exams.

Other Books:

• Revision Notes for MCEM Part A
• Essentially the syllabus but annotated with bullet points, is also as you would expect a little bit bulky. Notably contains a few errors, but there really aren't any alternatives based on the syllabus directly.
• Can be useful for a quick dip on specific topics, but leans towards specific facts rather than explanations of base principles. Useful when used with other book.

• Basic Medical Sciences for MRCP Part 1, 3e (MRCP Study Guides)
• This might not be specifically for us but with the degree of overlap of basic sciences this is a book worth a read. Anecdotally the content seems to correlate with some common Mcem questions
• It is also worth having your favourite anatomy text and a specific microbiology book.

For Part B:

• Revision Notes for MCEM Part B
• My goto book at the moment, covers the whole syllabus in good depth with common exam topics and tips flagged up.
• Includes example SAQ's based on each chapter and previous papers.
• Get Through MCEM Part B: Data Interpretation Questions
• About to start this one and will update it as I work through it, but it written by some of the team behind the Bromley courses so has some credibility.

For Part C: - I'm not quite here yet so watch this space...

AND Finally...

For those who have made it to the bottom of this post a bite of information...

Parkland formula for fluid requirements for the first 24 hours in burns:

Burn Surface Area (BSA) x Weight (Kg) x 4             BSA x W x 4 (8/16)

Notably the clock starts at the time of the injury and half should be given over the first 8 hours, the second half over the next 16 hours. If a patient arrives 1 hr post injury you have 7 hours to give the first half.

A is a good place to start...

So let's start with an Airway question...

A three year old attends the ED late at night with her mother. She has had a barking cough and stridor on exertion. Her sats are 96% on air and she appears relatively well.

1) What are the normal heart and respiratory rate for this child? (2 marks)
2) Give SIX differentials for stridor in this age group. (3 marks)
3) List THREE drugs including dose and route for stridor. (3 marks)
4) Name and give three components of a scoring system for croup. ( 2 marks)

Answers will follow later in the week...

Resp Rates:
Neonate	30-50
Infant	20-30
Child	20-30
Adolescent	15-20

Give six differentials – 0.5 mark each•Croup (laryngotracheobronchitis) – rougly 80%•Epiglottis•Foreign body•Airway Trauma•Anaphylaxis/ angioedema•Retropharyngeal abscess•Diptheria•Smoke inhalation•Whooping Cough

List 3 drugs (including dose and route) used for  stridor- 0.5 for drug, 0.5 for dose & route
•Dexamethasone 0.15-0.6mg/kg, PO•Budesonide 1-2mg neb,
•Adrenaline 5mls 1:1000 neb.•Clever marks for heliox