Tuesday, 23 March 2010

Causes of Anaemia

Causes of Microcytic Hypochromic Anaemia

TICS - "Tiny Tics cause Microcytic Anaemia"

Thalassaemia
Iron deficiency
Chronic disease
Sideroblastic anaemia

or "Find Those Small Cells" * - I think this is my favourite

Find = Fe deficiency
Those = Thalassaemia
Small = Sideroblastic anaemia
Cells = Chronic disease.

or "Heavy Sid 's Always after Tha Lasses"

Heavy = Fe = Iron Deficiency
Sid's = Sideroblastic Anaemia
Always = Chronic Disease
Tha Lasses = Thalassaemia


Causes of Normocytic Normochromic Anaemia

ABCD

Acute blood loss
Bone marrow failure/infiltration
Chronic disease
Destruction (haemolytic) anaemia

'nuff said


Causes of Macrocytic Anaemia

"Macdonald's do FAB burgers"

Folate deficiency

Alcohol abuse
B12 (thiamine) deficiency

or

"FAT RBC"

Foetus (pregnancy)
Alcohol
Thyroid (hypo)

Reticulocytosis
B12/Folate
Cirrhosis

or

"FAT RBCs make me MAD"

Foetus (pregnancy)
Alcohol
Thyroid (hypo)

Reticulocytosis
B12/Folate
Cirrhosis

Multiple Myeloma/Myeloproliferative Disorders/Myelodysplasia
Aplastic Anaemia
Drugs (Methotrexate, Zidovudine)

and remember that both B12 and Folate are Megaloblastic, while the rest are Normoblastic.

with help from:
http://www.passmed.co.uk/anaemia.html
http://www.scribd.com/MemorableMedicine

Friday, 19 March 2010

Fractures #1

What is a Fracture?
A break in the continuity of the bone, which also results in damage to the surrounding soft tissue.

Types of fracture

Open fracture (compound) - where the surface wound communicates with the fracture itself, allowing for the possibility of contamination and infection.
Closed fracture - The skin or wound has an intact surface.
Intra-articular fracture
Extra-articular fracture
Displaced fracture
Undisplaced fracture

Transverse
Oblique
Spiral
Multifragmentary/Comminuted - >2 fragments
Avulsion - bony fragment torn off by tendon/ligament

Compression/Crush - crumpling of cancellous bone (calcaneum, vertebral)
Stress - repeated stress = bone fatigue
Greenstick - cortex has buckled on one side through bending rather than breaking, children
Pathological - fracture in a bone already weakened by disease. Through generalised bone disease (OP)/localised abnormality (mets)

OP fractures - *spine & femoral neck

Displacement of fractures
Impaction - fragments are driven into each other, causing shortening
Angulation/Alignment - fragments are in angle with each other. Describe in degrees & distal fragment,
Opposition - lateral displacement
Rotation - observed with mismatched widths of distal and proximal fragments.

Dislocation - complete loss of congruity between the articular surfaces of a joint.
Subluxation - partial loss of contact between two joint surfaces.

Fracture Healing

1) Bleeding into fracture
2) Inflammatory Reaction
3) Cell Proliferation, callus formed
4) Consolidation, lamellar bone
5) Remodelling under stress

Plastering
UL - 6 weeks
LL - 12 weeks

Wednesday, 17 March 2010

Cardiovascular Examination - The Script

WIPER

Washes hands.

Introduces self.
&
Asks Permission to examine the patient.

"Hi, my name is __________, I'm a final year medical student. Would it be alright for me to listen to your heart? Thank you."

Expose
&
Reposition

"I would like to have the patient at 45 degrees and exposed from the waist up. 
 Is it alright if I put you at 45 degrees? And are you fine to be undressed from the waist up? Thank you so much."

General Inspection


Bedside - 
"I'm looking around the bed for any 
- ECG leads,
- O2 therapy, 
- or medication, for example, GTN spray."

The Patient -
"I'm looking at the patient to see 
- if they look ill,
- are they SOB at rest,
- is there any cyanosis?
- Are they overweight or cachectic?
- Is there any obvious genetic syndrome, for example, Marfan's?"

Hands -
"Do you have any pain in your hands at all? May I have a look and feel of them?
I'm initially assessing for 
- the temperature 
- and hydration - are the hands particularly sweaty or clammy?
At the nails I'm testing 
- the cap refill 
- and looking for splinter haemorrhages.
At the sides of the fingers I'll inspect for
- signs of clubbing
- or tar staining.
I am then looking at the palms and finger pulps for 
- Janeway lesions 
- or Osler's nodes."

Wrist -
"At the patient's wrist 
- I'm feeling the radial pulse to assess its rate and rhythm."

Upper Arm  - 
"At the antecubital fossa 
- I'm palpating the brachial pulse, to assess rate, rhythm and character. 
- I would at this point also like to take the patient's blood pressure.
Do you have any pain in your arm or shoulder? If it's alright, I'm just going to pull your arm up, relax - it shouldn't hurt.
- I'm testing for the presence of a collapsing pulse."

Neck -
"I'm just to feel your neck now.
- At the neck I am palpating the carotid pulse to assess the rate, rhythm and character.
Can you look to your left, and rest your head against the pillow/my hand?
- I'm assessing the JVP to see if it's raised, and moves with respiration.

Eyes -
"Can you look at the ceiling for me? I'm just going to pull down your lower lid, if you don't mind.
I'm looking at the 
- sclera to assess for any sign of jaundice, 
- and I'm looking to see any paleness of the conjunctiva.
And look straight ahead now.
I'm looking at the 
- iris for corneal arcus.
- I am looking around eyes for xanthelasma."

Cheeks -
"I am looking at the cheeks for mitral facies."

Mouth -
"Can you open your mouth for me?
I am looking at 
- the lips for peripheral cyanosis
- I am looking at the soft palate
- and assessing the dentition.
Can you raise your tongue to the roof of your mouth?
I am looking 
- under the tongue for signs of central cyanosis.
You can relax your mouth now."

CHEST


Inspection - 
"I'm looking at the chest for 
- any scars, 
- pacemakers, 
- abnormal chest movements or shapes, 
- and whether there are any visible pulsations.
- I can also check their leg to see if I suspect vein graft surgery."

Palpation -
"Do you have pain in your chest? If it's fine I'm just going to have a feel of your chest. Can you lean to the left for me?
- I am palpating the apex beat.
- I am also palpating for the presence of heaves or thrills."

Auscultation -
"I'm just going to have a listen now - you can breathe normally.
- I am listening at the 4 areas, with both the bell and the diaphragm of the stethoscope.
Can you breathe in for me and hold your breath. Ok, thank you, now can you breathe out for me and hold your breath. Now breath normally. Can you sit up and lean forward for me? Can you lean towards you left-hand side for me?
If there is an abnormal sound I am assessing 
- the time, 
- the site and radiation (either at the carotids or the axilla), 
- the loudness and pitch, 
- and the relationship to respiration and posture.
Can you hold your breath for me?
- I am also listening at the carotids for any evidence of bruits.
You can breath normally now.
Can you lean forward for me?
- I am listening for evidence of basal crackles.
- I am also checking for sacral oedema.
Ok, you can lean back on the bed and relax. Thank you very much _______, I'm all done - do you need any help putting your clothes back on?

To finish off the exam I'd like to examine
- the peripheral pulses, 
- palpate the lower limbs for peripheral oedema,
- record an ECG, 
- do a urine dipstick
- and if relevant - check the legs for scars from vein grafts, and examine the abdomen, particularly the liver if I suspect right heart failure.
Thank you again."

The ''And finally..." can be remembered handily by
DOPE as in "the person who writes this blog is dope... and for some reason I'm using slang from the 90s."

Dipstick
Oedema
Peripheral Pulses
ECG

I thank you.
Take a bow. Take a bow.

Saturday, 13 March 2010

Risk Factors - Thromboembolism

The major risk factors for DVT/PE can be remembered with the mnemonic

His Leg Might Fall Off

History of thromboembolism
Immobility (hospital/institution)
Surgery (*abdominal/pelvic/orthopaedic)
Varicose Veins in the Leg
Malignancy
Fracture/Trauma
Oestrogen (pregnancy - *late, OCP, HRT)

thanks to:
http://youngmongoose.blogspot.com/2010/02/dvtpe-risk-factors.html

Minor Risk Factors include:
CVS - MI/HT/Heart Failure/Indwelling Central Line
Resp - COPD
Haem - Thrombophilia eg antithrombin, Protein C or S deficiency/Factor V Leiden mutation/aPPL antibody/Prothrombin variant/Homocysteinaemia
Polycythaemia/Thrombocythaemia/PN Haemoglobinuria/Sickle Cell Anaemia
ID - Serious Infection
GE - IBD/Obesity
Renal - Nephrotic Syndrome

Also important to recall:

Virchow's Triad
  • Endothelial Injury
  • Stasis
  • Hypercoagulability
Imagine the tube at rush hour - stuck (stasis) at station, filled with people (hypercoagulability) with their bags and briefcases stuck in the doors (endothelial injury).

Thursday, 25 February 2010

Infective Endocarditis

Infective Endocarditis has several predisposing factors.

These include
 - Rheumatic heart disease
 - Mitral Valve Prolapse
 - Intravenous Drug User
 - Congenital Heart Disease (*bicuspid aortic valve)
 - Prosthetic Valve
 - HOCM

(imagine an pregnant (Cong. HD) IVDU, collapsed (MV Prolapse) in a room (Rheum), with a prosthetic leg (prosthetic valve) made by the HCME (HOCM) company) Yeah, I know it's messed up.

Several organisms tend to be the culprit with this condition:

  • Viridans Streptococci
  • Streptococcus Bovis
  • Staphylococcus Aureus
  • Enterococci
  • Gram Negative
(imagine a smiling (VS) cow (SB) in a pink cloak (gram -ve) holding a staff (SA) beckoning you to enter (Enterococci).

Clinical Features include:
 A) Fever (*90%)
 B) Anorexia & Weight Loss
 C) Clubbing
 D) Splinter Haemorrhages
 E) Osler's Nodes
 F) Janeway's Lesions
 G) Petechiae
 H) Roth's Spots
 I) New or changing murmur
 J) Systemic Emboli
 K) Splenomegaly
 L) Haematuria

ECGs for the Incredibly Slow!!

... That's the title of the book my publishing empire is going to kick off with.

They'll all be titled "[INSERT NAME OF SUBJECT] for the Incredibly Slow!!" Of course there are exclamation marks. Us slow people need all the help we can get. It'll be written by a slow person - for slow people. I predict millions.

Like the CXRs, ECG reading, for the majority of it, is reading what's in front of you out loud and getting complimented on it. Yeah, at the end you're expected to deliver a diagnosis, but that's only the most minute-simultaneously-important part of it. And to look your slickest you need a system. Like counting cards, only with less fun or money.

How To Report An ECG
 "Please Miss-Amazing-Medical-Student-Person, can you report this ECG for me?"
"Of course I can, can I just let my insides shrivel up and die first, due to the inevitable humiliation about to occur?"
"Sorry?"
"Oh, nothing, sorry I meant..."

A) Rate - what speed (R-R interval)? tachy/brady?
B) Rhythm - where from - sinus/ventricular? regular/irregular?
C) Cardiac Axis - left/right axisdeviation?

D) P Wave - is it normal/peaked & tall/notched and broad?
E) PR Interval - is it regular/prolonged? (N=3-5 small sq)
F) Q Waves - are there any abnormal Q Waves present?
G) QRS Complex
    1) Height - are there particularly tall R waves in V1 or V6?
    2) Width - are they abnormally wide? (N=3 small sq)
    3) Transition Point - is the where R=S around V3 or V4?
H) QT Interval - abnormally short or long? (N=2 large sq)
I) ST Segment - raised/depressed in any of the leads?
J) T Waves - are they inverted/peaked/flat?
K) U Waves - are there any at all?

Basically - just travel along the ECG line, and you'll be fine.

Data Interpretation - What fun!!

Ah medical school - years of looking at stuff and not knowing what it means, but pretending you do. But then final year rolls around and you realise you actually HAVE to know what stuff means. Well. I didn't see that coming, did you?

How To Interpret A Chest Radiograph (without getting cross-eyed)

The X-ray has essentially 5 shades of grey, which is why they make for riveting viewing:
BLACK = Gas
DARKER GREY = Fat
LIGHTER GREY = Soft Tissue
WHITE  = Bone
BRIGHT WHITE = Man-made

The Interpretation comes in 3 part
1) The Spiel - the boring, but necessary details
2) The Film - the technical quality
3) The Chest - the actual findings

Firstly the spiel, this sounds well impressive if done slickly, but essentially you're just reading out loud..
a) Type of Projection + Any specific techniques
b) Name of Patient
c) Age/DOB of Patient
d) Date Taken
e) Location Taken

"e.g. This is a (1)PA film of (2)Mrs - , a (3)56 yr woman, taken on the (4)--/--/-- in (5)A&E, after she presented with..."

Types of Projection:-
PA/AP/Lateral/Supine/Erect/Semi-Erect (the patient is upright, but not in an ideal position) and Mobile.
Techniques include if it was taken in expiration etc.

Secondly, the film, where we get to criticise x-ray technicians when they can't hear us.
Morbidly we use the acronym RIP to assess these,

Rotation
Inspiration
Penetration

Then the chest, remember not to get too excited at this bit, though it's what everyone's been waiting for.

First - the weird thing you can't stop looking at. Calling it such is not so good, but cleaning it up as "the most striking abnormality on initial assessment is..." Continue on that system if ti feels natural - otherwise go for...
Airway - assess the trachea, mediastinum and the hila
  • Deviation of trachea
  • Width and contour of mediastinum
  • Size and density of the hila
  • Level and symmetry of the hila

Breathing - Lungs and pleura
  • Size
  • Parenchyma
  • Vascular Lung Markings
  • Pleural thickness or calcification
  • Opposition against chest wall e.g. pneumothorax
Circulation - Heart and major vessels
  • Heart size, size of chambers
  • Outlines of aorta, IVC and SVC
  • Man-Made stuff e.g. stents, clips, wires, valves, pacemakers
  • Size of pulmonary vessels
Denser stuff (yeah, it doesn't totally work) - Bones and soft tissues
  • Bone disease, fractures, bony deposits
  • Surgical Emphysema
  • Breast presence/absence/symmetry
2) Then the Review Areas otherwise known as the stuff you forget.
From top to bottom...
Apices
Behind the Heart
Breast Shadows
Costophrenic Angles
Below the Diaphragm
... which sort of works.

Remember!!

ALWAYS compare to a previous x-ray if possible.
The X-ray is a 2D image of a 3D structure.
Never stop looking for stuff!! Make the examiner bored!! Still be there when the lights are off and everyone has gone home!!