Explaining Cystic Fibrosis

Cystic Fibrosis is a common explaining station in OSCEs, so I’ve put together some things to say about it to parents/lay people/bus drivers who may be interested.

1. Introduction

As always:

  • Wash hands
  • Introduce yourself
  • Explain why you’re there
  • Check you’ve got the right patient
  • Check they’re happy to talk to you

2. What do they know?   (See OSCE communication checklist top 5 post)

  • Ask what they understand so far
  • Ask what particular concerns they have
  • Make sure you know what they want from the consultation

3. Answering specific questions:

  • What is it?

Cystic Fibrosis or CF is a genetic condition, where the body isn’t able to make the secretions it makes watery enough. This means that any body part that makes these secretions, such as the lungs, the pancreas and the intestines can run into trouble with thick, sticky mucus. This is why people with CF often have recurrent chest infections, and tummy problems.

  • How common is it?

In short, not very. Around 1 in 2500 people are affected. Because you receive a copy of DNA from your mum, and a copy from your dad, both of these copies have to be defective for CF to occur. This means your parents are both ‘carriers’ – they have one defective gene, but they don’t have symptoms because the other copy is working fine. Approximately 1 in every 25 people is one of these ‘carriers’ of the defective gene.

*Here I would draw a diagram about recessive inheritence*

When two people conceive a child, that child receives one of the mother’s genes, at random, and one of the father’s. This means that there are four possible combinations for this gene – Fine/Fine, Fine/defective, defective/Fine, and defective/defective. CF occurs when both are defective, so there is a 25% chance that two carrier parents will have a child with CF.

  • What are the symptoms?

Usually CF is picked up quite early on, as the baby will have recurrent chest infections, and they may struggle to put on weight as well. They may also be wheezy or short of breath, and have diarrhoea. It is usually detected as part of a screening programme for all babies, though, called the heel prick test. We also have a ‘sweat test’ and genetic tests available to diagnose the condition in older children.

  • Could I have prevented it?

There was no way without both you and your partner being specifically genetically tested that you could have known you had the genes, and even then there was only a 25% that your child was affected. There was nothing that you could have done to make it more or less likely.

  • Is there a cure?

Currently there is no cure for the condition, so the main focus is on dealing with the problems that may arise. This includes using antibiotics to prevent chest infections, medicines to help open up the airways and shift the sticky mucus, and providing dietary advice and nutritional supplements to help their growth and development.

  • Is it going to kill my child?

The problem with the sticky mucus and the repeated infections is that it takes its toll on the lungs, and they become progressively more damaged over time, making CF a progressive condition. Currently the only treatment for this that we have is a lung transplant. Currently the life expectancy for people with CF is that over half will live beyond 40, however we anticipate that those children born with it now will live longer than this.

  • What can I do to help?

Ensuring your child eats well and does regular exercise is the best thing you can do, as they will need more calories and the exercise will help shift the mucus. Making sure nobody in the home is smoking, and generally reducing exposure to pollution and smoke will help reduce infections, as will making sure people at home are washing their hands regularly.

  • How can I prevent another child from having it?

Since you have had one child with CF, we know both you and your partner are carriers. This means any future child also has a 1/4 chance of the condition, however new techniques such as IVF allow us to select embryos that are not affected. Clearly that’s another conversation to have on another day, but there are certainly options.

  • Where can I get more information?

I’ll get you a leaflet with all the things we’ve discussed, and it also has some useful websites and contact information should you like more information. There are huge amounts of information online, as well as support groups including the Cystic Fibrosis Trust so it’s definitely worth looking it up, and if you have any other questions do feel free to get in contact with us again and we’d be happy to help. 

4. Wrap it up

Make sure you end by checking the person’s understanding:

“Before we finish, can I just check that I’ve explained it properly? Could you tell me the main points of what we’ve discussed?”

“Have I answered your questions? Please feel free to ask more”

5. Thank your patient and wash your hands


Falls are bad. Most people recognise this fact. However they’re particularly bad in the elderly for a number of reasons, making them the leading cause of mortality in those over 75. Preventing them is a damn sight better than trying to deal with the consequences.

Reasons why falls are bad:

  • They hurt
      • fear of falling and loss of quality of life
      • loss of independence
      • residential home admittance
  • They cause damage
      • osteoporosis and co-morbidities make fractures more likely
      • Fractures lead to immobility, pain, and risky operations
      • They also cost a lot (£5 million a week)
  • They can cause much more damage
    • If on the ground for a long time
      • This can lead to muscle breakdown and kidney damage (rhabdomyolysis)
      • They may not be able to take their medication while on the floor (comorbidities)
      • They may be bleeding, and if they’re on Warfarin, this is going to be worse

Risk factors for a fall are important, and need to be ruled out, or at least acknowledged before letting someone go home, especially if they live alone:

If anyone is going to fall, it’s Marjorie. She’s 80, and a very thin little lady who’s had a lot of health problems in the past. She fell down the stairs last year and has since become dependent on her daughter to help look after her at home. She gets terribly confused about her medications because there are so many, and she worries about falling over because she has to keep rushing to the toilet every so often. Her son bought her some crocs for her birthday, which made her very sad, but the whiskey made it a little better…

  • Over 80
  • Female
  • Low BMI
  • Previous fall
  • Already dependent
  • Polypharmacy
  • Confusion
  • Other illness
  • Urinary incontinence
  • Inappropriate footwear
  • Home hazards
  • Depression
  • Alcohol abuse 

When someone presents with a fall, you should try and figure out why they fell, as this will affect your management significantly. Furthermore, patients will often hide the fact that they’re falling as they’re aware this increases the chance of admission to a care home. Make it clear that you want to help them maintain as much independence as possible, and by telling you what’s causing it, you might be able to help!

  • I tripped over the rug – Occupational Therapy help make homes safer
  • I stood up and everything went fuzzy – Orthostatic hypotension 
  • I leant my head back and fell – balance issues
  • I forgot to take my diabetes medications – hypoglycaemia
  • I got up straight away and felt fine – less worrying than ‘I was on the floor for five days’
  • I found it difficult to talk afterwards – stroke/TIA
  • I can’t find my glasses – eyesight problems

One of the best ways to figure out what happened is a collateral history – ask the patient if anyone else saw what happened.

  • Did they shake/bite their tongue

Bone health is also an important factor to consider, as fractures are more likely to occur in the elderly due to:

  • Osteoporosis
  • Osteomalacia
  • Paget’s disease of bone
  • Metastasis and malignancy

Two simple tests:

  • Timed up and go – ask the patient to stand up without using their hands, walk three metres and turn around and sit down again
    • If they can do this without wobbling then they are low risk
  • Turn 180 – ask the patient to turn so they’re facing the other way
    • If this requires more than four steps then further investigation is warranted

Preventing falls in the future:

  • The house
    • reduce risky obstacles, rugs, exposed wiring, furniture etc
    • wet floors
    • handholds and railings
  • The patient
    • ensure a good diet
    • encourage mobility and exercise
    • pilates and yoga to improve balance are best
    • encourage socialising and group activities to ensure independence and to allow others to check they are alright
  • The treatment
    • always review and query any medications and whether they are indicated
  • The fall
    • ensure that if the patient does fall, they are able to call for help quickly – pendant alarms etc

My general rule – If this person were my grandmother, would I be happy with her living on her own?

Antepartum haemorrhage

This is how I remember the key points about antepartum haemorrhage:

Annie is a 25 year old lady who is 25 weeks pregnant. She doesn’t know much, but she does know she’s having twins. Her anomaly scan shows a low placenta with a clot behind it, and also some exposed vessels between the placenta and the baby.

She has had a number of STI’s in the past, and recently hurt herself falling off her bike, which caused some bleeding from the groin.

The doctor goes to examine her but Annie slaps her hand away and says, “I have a placenta praevia, so you can’t touch this”

Just at that moment, Annie starts bleeding torrentially, and goes very pale. She gets very hot, panics and collapses on the floor. She begins to urinate blood as well and the doctor sets up a transfusion to try and replace some of the blood, before she also puts on some TED stockings. The CTG shows marked foetal distress and very quickly the tiny foeti show no signs of life.

  • Affects 2-5% of pregnancies
  • Defined as haemorrhage after 24 weeks of pregnancy and before birth
  • Mainly idiopathic
  • Placenta usually the cause:
    • placenta praevia (more likely with twins)
    • placental abruption
    • vasa praevia
  • Genital causes:
    • cervicitis
    • trauma
    • vulvovaginal varicosity
  • Be sure to exclude a placenta praevia before performing a digital vaginal examination
  • Complications:
    • anaemia
    • consumptive coagulopathy (DIC)
      • can give 4 units of FFP and 10 units of cryoprecipitate
    • shock
    • psychological sequelae
    • renal tubular necrosis
    • transfusion and its complications
      • VTE risk
    • foetal hypoxia
    • iugr and sga
    • foetal death


Someone has collapsed. You must fix it.


Before you go in:

Read the vignette before you enter the station and think about these:

  • What’s the patient’s name? This is quite important
  • What are you (other than sweating)? Does it say you’re a doctor, student, or passer by? This is what you’re going to have to introduce yourself as.
  • Where are you? On a ward? On the street? What equipment are you likely to have?
    • is there likely to be any danger?
    • bag valve mask (instead of rescue breaths)?
    • auto defibrillator?
    • call 999 or 2222?
    • have you got someone to help you?
    • is it likely trauma was involved?
    • What are your four Hs and Ts of Cardiac arrest?
      • Hypoxia
      • Hypovolaemia
      • Hyper/po kalaemia (metabolic disturbance)
      • Hypothermia
      • Tamponade
      • Tension pneumothorax
      • Thromboembolism
      • Toxins

Deep breath. Check your own pulse so you know whether you’re feeling yours or theirs. Chill. It’s going to be just fine.

As you go in:

Grab a tiny squirt of hand gel and some gloves. Stick them on as you start talking to the patient.


  • Danger
  • Response
    • call their name
    • shake their shoulders
    • squeeze trapezius
  • Call for help
    • If in a bed, lower it in case of needing to do CPR, and drag the bed clear of the wall, to ensure people can access both arms and the head
  • Airway
    • look in their mouth
    • head tilt, chin lift
    • jaw thrust if gurgling noises or risk of spinal injury
  • Breathing
    • listen for ten seconds, while watching their chest and feeling for carotid pulse
    • don’t let hair/necklace/dreads dangling into patient’s mouth
  • 2222 (or 999 if outside)
    • ask assistant to do this
    • “Please could you call 2222, adult cardiac arrest in the Plastic Dummies Ward, and on your way back could you bring the crash trolley, and let me know when it’s done”


  • Chest compressions – it’s all in the hips
    • heel of the right hand on patient’s sternum, 
    • fingers extended, wrists extended, elbows extended
    • left hand on top of right
    • 30 compressions, 5-6cm (1/3 of patient’s chest depth) at 100-120bpm
      • pretty much all house/electro music is 128bpm so if you have that in your head while you do it you won’t be far off
      • count the compressions out loud
    • 2 breaths
      • preferably with bag valve
      • watch the chest rise
      • preferably done by assistant if they’ve returned
        • they might hold mask on face and you use left hand to do the breaths (hence right hand on the bottom for compressions)
    • repeat until crash trolley and/or help arrives


Your first priority is to tag someone else in – ask them if they can take over compressions, and say you’ll count them in, and they should take over after the 2 breaths. Count on alternate compressions:

“3…press…2…press…1…press” —- 2 breaths —- they begin.

Now you’re clear to think. If there’s only 2 of you, you can take over airway.


Pads, pacemaker and piercings

  • one over apex, other just below right clavicle
  • >8cm from pacemakers
  • away from piercings and jewellery (doesn’t need removing, just move away)
  • one on the back if needed

Select, stop, shock?

  • select the ‘pads’ option for trace monitoring on the defibrillator
  • call to stop CPR and check the rhythm
    • you have 5 seconds to assess the rhythm, the first 3 are needed to let the rhythm settle after CPR stops
      • if it looks like a normal or vaguely organised trace, check for pulse 
        • if pulse, stop cpr
        • if no pulse, back on the chest
      • if not normal, decide if shockable
        • shockable – VF, pulseless VT
        • non-shockable – PEA, Asystole

Continue, Charge, Clear

  • While CPR is happening, say:
    • “Continue CPR, everyone else clear, oxygen away, I’m charging” and press charge
      • (150J biphasic)
  • Once charged:
    • “Stand clear, shocking”
    • Shock
    • Back on the chest

Time, think, treat

Ideally you would have these jobs delegated, with a system running like clockwork, allowing you to think.

Have someone timing (using the clock on the defibrillator) and counting the number of cycles

  • rhythm and shock check every 2 minutes

Think about your Hs and Ts and what might be causing this, and how you might treat it

  • Look at their drug chart
    • opiate painkillers
    • potassium sparing/losing diuretics
  • Listen to the chest
    • equal air entry? Tension pneumothorax? Tamponade?



  • during CPR:
    • establish a definitive airway
      • cuffed endotracheal tube in the trachea with the cuff inflated is the only secure airway
    • get IV access
      • if you can’t, get IO access
      • take bloods and send them off
        • FBC
        • U&E
        • Group and Save
        • VBG
    • have drugs at the ready
      • ADRENALINE 1mg IV – 10ml 1:10 000 pre-loaded syringe
        • every other cycle (3-5 mins)
      • AMIODARONE 300mg IV – after 3 shocks
        • if needed again, 150mg
        • infusion if still required
  •  Treat the cause:
    • Tamponade – pericardiocentesis
    • Tension pneumothorax – thoracocentesis (2 ICS Mid clavicular line)
    • Toxin – remove toxin/give antidote
    • Thrombus – thrombolysis
    • Hypothermia – warm patient
    • Hypoxia – 15l 100% oxygen
    • Hyper/po kalaemia – fix abnormal electrolytes
    • Hypovolaemia – IV fluid challenge

Continue until one of the following happens:

  • return of cardiac output
  • rhythm is no longer shockable, and a senior member of staff calls it


  • ABCDE assessment
  • Oxygen (sats >94%)
  • consider therapeutic cooling


  • Thank your team!


  • CXR
  • 12 lead ECG
  • Echo
  • Blood pressure
  • Bloods
  • Transfer to ITU
  • Write everything down
  • Go talk to relatives

Things to remember:


If you ask someone to do something, make sure you tell them to tell you when it’s done, to avoid confusion and help your thought process along.

Abdominal X-ray

Chest radiographs are phenomenal in terms of how much information they can provide given how simple and easy they are to perform. Abdominal films are also useful, but less commonly used as there are fewer indications for ordering them, and they don’t give the same wealth of information that a chest film can. Nevertheless, it’s essential that you can look at one without panicking, and get a rough idea about what’s going on inside that patient of yours.

Indications: “Gasses, masses, bones and stones”

  • Obstructed bowel
  • Perforated bowel
  • Bowel Ischaemia
  • Blunt or perforating abdominal injury
  • Intussusception
  • Foreign bodies
  • Suspected abdominal mass
  • Acute and chronic pancreatitis
  • Toxic megacolon


  • AP Supine
  • AP erect
  • Lateral decubitus
  • Supine lateral
  • KUB

Step 1: The basics

  • Patient Identity
    • right patient
      • name
      • date of birth
      • hospital number
        • always always always check all three – statistically the probability of two patients in the hospital having the same name and date of birth is scarily high…
    • right time
      • are you looking at a previous scan or the most recent
    • right view
      • is it the same as the one you ordered?
      • is it adequately exposed?
      • can you see the whole abdomen


Step 2: Gasses 3,6,9

  • Small bowel
    • Look for valvulae conniventes – or rings that distinguish small bowel from large
    • Small bowel shouldn’t be more than about 3 cm in diameter
  • Large bowel
    • Look for haustra – lines only go part way across the large bowel
    • The retroperitoneal parts are easier to find as they’re relatively constant in their location:
      • ascending
      • descending
      • rectum
    • Large bowel shouldn’t be more than 6 cm in diameter
    • The caecum shouldn’t exceed 9 cm
  • Walls
    • gas in the wall of bowel suggests ischaemic colitis
  • Air-Fluid levels
    • more than four or five visible fluid levels, great than 2.5 cm long is abnormal and may suggest:
      • gastroenteritis
      • ischaemia
      • obstruction
      • ileus
  • Peritoneum
    • Rigler’s sign (double wall) is a sign of intraperitoneal gas, and may reflect perforation or penetrating trauma
    • air may be seen under the diaphragm
  • Soft tissues
    • surgical emphysema may be visible especially after trauma

Step 3: Masses

  • Solid organs
    • Liver
      • Right upper quadrant
      • Grey
      • Breast tissue may overlie the upper aspect
      • May have cholescystectomy clips present
    • Spleen
      • Left upper quadrant
    • Kidneys
      • T12-L3
      • Right lower than left due to liver
    • Bladder
  • Psoas muscles
    • bulging may indicate a retroperitoneal pathology
  • Vessels
    • Calcifications may indicate an aortic aneurysm

Step 4: Bones

  • Ribs
  • Spine
  • Sacrum
  • Pelvis
    • Check all of these for:
      • fractures
      • degeneration
      • metastasis
      • cysts


Step 5: Stones

  • Stones should be looked for in the:
    • Kidneys
    • Ureters
      • follow the tips of the lumbar transverse processes down to the sacroiliac joint
      • The ischial spines mark where the ureters enter the bladder
    • Bladder
    • Gallbladder
    • Pancreas (calcification)



  • Piercings may look like foreign bodies
  • Not all calcification of soft tissues is clinically important


Hope this helps!









The 1 minute rule

If something takes less than a minute, do it now.


I used to be absolutely terrible when it came to having a whole load of little jobs to do. I’d try and work out the best order to do things in to be productive, or write a list and work my way down it but it seemed so frustratingly endless. So I started using the one minute rule. If you’re part way through a task, and another one lands in your lap, either from an email, facebook post or housemate – and it is likely to take less than a minute to achieve, do it straight away.

The logic is that if you add it to the list of things to do, or try and work out when best to do it, you’re already spending nearly a minute just fretting about when to do it, so why not just get it done?


Here’s a story to help remember some of the details of intussusception. Remember to try and really picture this event, in your garden. If you can use children that you’ve seen or know, it will help make the story stick better. If you can make it even more ridiculous than I have, then go for it – the weirder the better!

Two boys and a girl are playing in the garden at a family barbecue. The boys are 6 months and 18 months old, and the girl is 12 months old.

  • Typically affects children between 6 and 18 months
  • Boys are twice as affected as girls

They’re all dancing, and doing a special dance where they have to jump as high as they can, and bring their knees up to their chest. As they’re doing this, they all turn completely white and start rolling around on the floor complaining of pain in their abdomen.

  • Child complains of abdominal pain
  • Often characteristically draws knees up to chest
  • Pale
  • Characteristic ‘Dance’s Sign’

One of the boys then does a poo. Unfortunately all he’s been eating is jelly, so he blasts jelly all over the other two. They both vomit, but since they’ve just been eating sausages from the barbecue, there’s now jelly and sausages all over the garden.

  • Vomiting
  • Blood-stained faeces (like jelly)
  • Sausage like mass palpable in the lower right quadrant

The children then all start screaming, but they’re screaming at such a high pitch that it’s causing all the windows to smash, so you then have to go on a trip to Target to buy replacements.

  • Ultrasound is the primary imaging modality
  • Characteristic ‘target’ sign seen

The Background

Intussusception is a medical emergency in which part of the bowel collapses into the adjacent part like a telescope (or extendable selfie-stick for those born after 1994). It can lead to obstruction and perforation, and then sepsis and shock.

The reason it’s dangerous is because the segment of bowel that is drawn in can have its blood supply cut off, and become necrotic and then perforate. The ischaemic bowel loses its mucosa into the bowel lumen, and this forms the characteristic ‘red jelly’. In reality, any type of blood in the stool should have intussusception on the differential diagnosis, especially if the child is between 6 and 18 months.


A variety of things can cause intussusception, although how it is that they do it isn’t well understood. It is thought that enlarged lymphoid tissue after an infection may play a role, and this would also explain why intussusception is relatively rare in the first three months of life, while the infant is still protected by passive immunity.

The different types include:

  • ileocolic (90%)
  • ileoileocolic (less common)
  • ileoileal (rare)
  • colocolic (rare)


The diagnosis is made based on:

  • clinical examination
    • PR exam can be very helpful in children
  • history
  • Dance’s sign
    • emptiness in the lower right quadrant
    • sausage shape in right upper quadrant
  • Ultra-sound Scan
    • diagnostic imaging modality of choice
    • gives a characteristic target shape

If you google intussusception you get some awesome radiographs

I can’t put any on here because I don’t own them

sad face

Breastfeeding drug contraindications

Which drugs should be avoided when breastfeeding?

Amy is on a low-carb diet. She is aspiring to be a supermodel

  • amiodarone
  • carbimazole
  • aspirin

Amy was breastfeeding her baby and sipping her drink by the swimming pool, when a mercedes benz followed by four bicycles plunged into the pool.

  • ciprofloxacin
  • chlorampenicol (chlorine in pool)
  • benzodiazepines
  • tetracyclines

The bicycles exploded in two huge clouds of sulphur, while the mercedes exploded because it was made of lithium.

  • sulphonamides
  • sulphonylureas
  • lithium

It was all very excyting.

  • cytotoxic drugs

The following drugs should be avoided:

  • antibiotics: ciprofloxacin, tetracycline, chloramphenicol, sulphonamides
  • psychiatric drugs: lithium, benzodiazepines
  • aspirin
  • carbimazole
  • sulphonylureas
  • cytotoxic drugs
  • amiodarone

Neonatal Hypoglycaemia risk

Some babies are at risk of hypoglycaemia. The following story should help you to remember the relevant risk factors!

It’s really early in the morning, and two babies wake up to find their mum collapsed on the floor. 

One baby is really small and the other is fecking massive. 

The mother has collapsed because she’s in DKA. 

She’s banged her head on the way down and there’s a lot of blood on the floor. 

Big baby thinks to slow the heart down to stop the bleeding and gives her beta blockers. 

The little baby doesn’t respond for 5 mins, and even then is hardly speaking. 

In fact all he does is pull a silly face and poo all over the floor.

  • preterm
  • low birthweight
  • large birthweight
  • diabetic mother
  • polycythaemia
  • mother on beta-blockers
  • APGAR <7 in first 5 mins
  • dismorphic face – suspected inborn error of metabolism


Read the full question

This is drilled into any student from a young age, and it never ceases to be true. Exam papers are minimalistic, they rarely contain any information that they don’t need (unless they’re testing your ability to sift through useless information…). This means that everything in the question is there for a reason, so analyse every bit

Eg. A 48 year old lady from Africa presents with…   

They’re not writing this for fun! This is saying ‘I want you to think about the risk factors for this age group and this nationality – use the information they’re giving you!

Keep the needle out of the flame

Don’t put a needle in inflamed tissue

This may sound obvious, but it applies all over the body. Needles hurt anyway, so sticking a needle into an infected or inflamed area is going to hurt a lot more, and risk spreading the infection. This applies to local anaesthetic, injection of botox into an overactive bladder, or injecting steroids into a painful joint.

The example of local anaesthetic:

Lidocaine doesn’t work well in an acidic inflamed environment, and the blood vessels in inflamed tissue are dilated to improve supply and drainage to the area, meaning the systemic spread is massively increase. Finally, the effective half life plummets as it all gets washed away. 


Follow me

Let the patient guide you

Searching for a diagnosis is like trying to find a certain room in a large building complex. The quickest and easiest way is to ask the person who knows where the rooms are and who has the keys to all the rooms.

This person is the patient.

Ask them where to go, and let them lead you. Don’t try and jump ahead, just follow them to the correct destination. If you start jumping, and thinking ‘I think this is pneumonia’, you’re essentially running ahead to a random room and asking ‘is it in here?’. Wait till the patient has told you everything, and see where you’ve ended up.