A Bolus is a bonus - fluid management in children

So fluids in kids is an easy topic for an exam as it follows clear rules, however it is tricky for ED doctors as most of us have limited paediatric exposure and it has some important differences to the management of adults. Children are far more prone to fluid shifts and the therefore poor fluid management of children can kill.

Below are a few simple rules aimed at giving safe answers that are suitable for an exam, the reality of the matter in the ED is that if you are in doubt there are all sorts of useful resources that can guide you e.g. your boss or the paediatric reg/ PICU. There are even apps to help with the calculations.

For the purposes of the below assume I am referring to 0.9% sodium chloride unless stated otherwise.

Step 1:

Know the child's weight, you cannot proceed without this, but you may have to work it out:

• 0-12  months: weight = (0.5 x age in months) + 4
• 1-5 yrs: weight = (2x age in years) + 8
• 6-12 years: weight = (3x age in years) + 7

Step 2:

Bolus for the shocked child: know the cause of shock

• Sepsis: 20ml per Kg
• Hypovolaemia/ trauma: 10ml per kg
• DKA: 10 ml per kg - do not exceed 30ml per kg in total - 
• and if you are managing a child with DKA and needing fluid boluses you should probably not be managing them on your own!!!

Step 3:

Maintenance fluids: "4-2-1 rule"

• 4mls per Kg for the first 10 kgs
• 2mls per Kg for 10-20 kgs
• 1mls per Kg for 20+ Kg

Worked example:

22kg child =

4mls x 10 +

2mls x 10+

1ml x 2 = 22 ml/ hr

Don't forget that maintenance will need to consider potassium and dextrose to be included in regime.

Step 4:

Special circumstances:

• DKA: can't stress this one enough - cautious fluid is the order of the day and rehydration may be undertaken over a 48 hr period!!!
• Burns: remember Parkland 4x %BSA X Weight - give half over first eight hours from injury and then second half over next sixteen hours.
• Dehydration: similar to burns you can calculate the deficit by working out the %dehydration x weight.
• Hypoglycaemia - weight x 2mls - here the fluid is 10% dextrose

Questions:

1) What is your estimated weight for a seven year old boy?

2) What would be a suitable maintenance fluid regime for this child?

3) He has sustained 6% partial thickness burns, what are his fluid requirements over the first 24 hours.

4) How much dextrose would a hypoglycaemic 6 month old require?

Diabetic Ketoacidosis- Glucagon is the Problem!

Another common topic and also a frequent presentation to the ED is DKA. On the whole I think of this as straight forward ie bang up some fluids and insulin and it'll sort itself out! That being said when you actually read about it things are a little bit more complicated.

Your hospital will have it's own policy and approach, but a nice little guide has been produced by the Joint British Diabetes Societies Inpatient Care Group:

http://www.bsped.org.uk/clinical/docs/DKAManagementOfDKAinAdultsMarch20101.pdf

Let's start with some background to put things in perspective:

• It is potentially life threatening, although mortality rates have fallen in the last 20 years from 7.96% to 0.67%!
• Cerebral oedema especially in children and adolescents is the most serious complication.
• The typical fluid deficit in DKA may be 100 ml/kg!
• It is now possible to measure blood ketones at the bedside.
• The treatment of DKA has developed and will continue to develop as our understanding increases.

The rest of this post is about adults, there are key differences in the management of children/ adolescents.

Definition:

1. Blood glucose >11
2. Ketones > 3 (or 2+ on urine)
3. pH <7.3 or bicarb <15

Pathophysiology:

Its a lack of insulin, right? Well yes and no.

Type one diabetics have impaired insulin production and therefore cannot bring their sugars down, but Insulin also acts to oppose other hormones (glucagon). It is this lack of opposition that causes the metabolism of fatty acids which in turn produces the ketones. So it is good to think of it as unopposed gluconeogenesis: the production of ketones lowers the pH and therefore gives us the acidosis ie. not a sugar problem.

Bang up some fluids and give insulin:

Treatment is aimed at correct the abnormalities and these patients are certainly dry and in need of lowering their blood sugars, but actually we need to think of treatment goals as switching off the gluconeogenesis and ketone production.

1. Fluid resuscitation - the link at the top contains a bit of debate as to the fluid to give, but essentially 0.9% Chloride is the answer because you can add potassium when it is needed.
2. Insulin- fixed rate infusion based on weight (0.1 units/kg/hr) - this corrects the sugars but also suppresses ketogenesis!
3. Monitor K+ and add it to fluids given - remember insulin will push it into intracellular space.
• hypokalaemia is a complication of treatment.
4. Give glucose when blood glucose is <14 - DKA is not a sugar problem but the production of ketones driven by glucagon, what we don't want is the sugar to fall and the gluconeogenesis to begin again!!!

What should I be worried about?

Things to worry about are the complications mentioned above: cerebral oedema and hypokalaemia.

Other things that warrant a higher level of care (HDU/ ITU) include:

• pH <7.1
• bicarb <5
• cardiovascular compromise
• Blood ketones >6
• Hypokalaemia on admission
• Anion gap >16
• Reduced GCS

Question:

A 36 year old lady who frequently attends the department with diabetic problems presents with a three day history of abdo pain and vommiting. She ways 65kg. Her observations are as follows: HR 117, Bp 109/76, RR 30, Sats 99% (21%). The results of her blood gas are as follows:

• pH: 7.23,
• Pa O2: 10
• Pa CO2: 1.4
• HCO3: 11.2
• Glucose: 36

a) What are the diagnostic criteria for Diabetic Ketoacidosis (DKA)? (3)

b) Write an appropriate prescription for an insulin regime in this patient. (2)

c) Give three features that should trigger discussion with critical care? (3)

d) What would be an appropriate fluid regime for this patient? (2)

Clever Marks:

Another question could quite easily ask you to calculate the anion gap - I have left this out of the gas information as I intend to do another medical maths entry on this topic.

Completely unpredictable...

So sometimes the exam just contains weird and wonderful things that you wouldn't expect - innervation of the female genital tract being an often quoted example. Then again other questions that come out of left field can with hindsight be identified as a popular issue around the time the exam was set. Another example that fits this is a major incident question following the 7/7 bombings.

So in light of that what sort of sort things have sprung to my mind? (if you can think of others please post in the comments).

1. Measles- recent outbreak in Wales. Questions could easily cover rashes/ other child infections and vaccination schedules. Also could be extended to meningitis or other infections amongst students
2. Over crowding: http://www.bbc.co.uk/news/health-24432072 a BIG issue at the moment, CEM have released a statement this week and did you know they have a document detailing their recommendations for dealing with over crowding (released approx a year ago!) www.collemergencymed.ac.uk/code/document.asp?ID=6296
3. Paracetamol - recent guideline change (again about a year ago).

Other things to think about:

• Capacity
• Consent
• DVLA guidance
• Child protection.

Question:

a) What markers indicate a department is overcrowded?

b) What steps can be taken in the ED to facilitate flow?

c) Define boarding.

d) At what point does the ED become responsible for a patient?

e) What steps can be taken to improve output problems?

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)

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?

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)

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.

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

First up some Free Stuff...

Ok, so this has started as a pet project alongside my revision for MCEM part B, its content should follow the path of the College of Emergency Medicine exams as I do.

The aim is to share useful resources and some notes I make based around the CEM curriculum and exams. Initially it may be more sharing/ highlighting other peoples good work, but as I get a feel for it I shall hopefully generate more of my own stuff.

I would like to create a resource for quick bites of revision to fit around work.

1) two websites with free examples of Part B SAQ's

http://www.mcemcourses.org - if  you haven't checked these guys out yet I would recommend doing so. I finally passed MCEM A after taking their course and I am booked on their Part B course (Expect a review after I attend). Their website contains several free resources for all parts of the exam including practice questions for part B. As further endorsement they are the authors of one of the few books for the exam.

http://mcemexamprep.co.uk - I used this website prior to my first sitting of MCEM A, but they also have sample questions for part B. I will be using their Part B questions over the next month.

2) Toxicology: 

had these shared with me by somebody else #Foamed
http://storify.com/nataliemmay/toxicology-revision-notes-for-fcem

3) Finally a tip from me... 

Local anaesthetic calculations can be tricky, but are a common exam question and an everyday activity in the ED. To work out how much lidnocaine is in a ml of a percentage solution simply multiply the percentage by 10.

• 1% x 10 = 10mg/ ml

Best of luck to all those sitting the exams...