Cerebral artery vascular territories and consequences

Anterior cerebral artery (ACA)

Supplies:

• Medial frontal lobe
• Medial parietal lobe
• Basal ganglia
• Anterior fornix
• Anterior corpus callosum

Signs and symptoms:

• Contralateral hemiparesis and hemisensory loss (lower extremities > upper extremities)
• Left hemineglect (right ACA)
• Aphasia (left ACA)
• Grasp and sucking reflex
• Flat affect
• Impaired judgment
• Urinary incontinence

Middle cerebral artery (MCA)

Supplies:

• Lateral frontal lobe (Superior MCA)
• Lateral temporal lobe and portion of parietal lobe (Inferior MCA)
• Internal capsule, corona radiata, basal ganglia (Deep MCA)

Signs and symptoms:

• Contralateral face and upper extremity weakness and spasticity (superior MCA)
• Non-fluent aphasia (left superior MCA)
• Hemineglect (right superior MCA)
• Fluent dysphasia (left inferior MCA)
• Right visual field deficit (left inferior MCA)
• Mild contralateral hemiparesis (right inferior MCA)
• Severe left neglect (right inferior MCA)
• Visual field deficits (right inferior MCA)
• Contralateral motor hemiparesis (deep MCA)
• Aphasia (left deep MCA)
• Left neglect (right deep MCA)
• Combination of everything (proximal MCA)
• Global aphasia (left proximal MCA)
• Left hemineglect (right proximal MCA)

Posterior cerebral artery (PCA)

Supplies:

• Occipital lobe
• Inferior/medial temporal lobe
• Upper brainstem
• Midbrain
• Thalamus

Signs and symptoms:

• Contralateral homonymous hemianopia
• Contralateral hemisensory loss
• Visual agnosia and prosopagnosia (not recognising human faces)
• Dyslexia (difficulty reading)
• Agraphia (difficulty writing)
• Anomia (difficulty remembering words or names)
• Thalamic pain (a form of chronic pain)
• Dysesthesias (abnormal sensation)
• Involuntary movements
• Weber's syndrome (oculomotor nerve palsy and contralateral hemiplegia or hemiparesis)
• Cranial nerve III palsy

Superior cerebellar artery (SCA)

Supplies:

• Superior cerebellum
• Dentate nucleus
• Lateral pons

Signs and symptoms:

• Limb ataxia
• Dizziness with nausea/vomiting
• Horizontal nystagmus
• Loss of ipsilateral conjugate gaze
• Contralateral H
• Contralateral Horner's syndrome
• Contralateral loss of pain/temperature sensation
• Loss of touch, position, or vibratory sense

Posterior inferior cerebellar artery (PICA)

Supplies:

• Lateral medulla and inferior cerebellum
• Lateral medullary syndrome (Wallengerg's)

Signs and symptoms:

• Ipsilateral or contralateral loss of pain and temperature on the face
• Ipsilateral limb and gait cerebellar ataxia
• Vertigo
• Nystagmus
• Ipsilateral Horner's syndrome
• Dysphagia
• Ipsilateral sensory loss

Anterior inferior cerebellar artery (AICA)

Supplies:

• Lateral caudal pons
• Small areas of the cerebellum

Signs and symptoms:

• Ipsilateral horizontal or vertical nystagmus
• Vertigo
• Nausea
• Vomiting
• Ipsilateral facial paralysis
• Ipsilateral loss of conjugate gaze to the side of the lesion
• Ipsilateral deafness and/or tinnitus
• Ipsilateral ataxia
• Ipsilateral loss of sensation over the face
• Contralateral impaired pain and temperature

Basilar artery (BA)

Supplies:

• Ventral pons
• Corticospinal tracts
• Long tracts
• Cranial nuclei
• Reticular activation system

Signs and symptoms:

• LOCKED-IN SYNDROME
• Tetraplegia
• Bilateral cranial nerve palsy (spared upward gaze)
• Coma (cognition spared)

Mental capacity assessment

Four main checklist points

1. The person understands what decision they need to make and why they need to make it, as well as understands both what happens if they do and if they do not make the decision
2. The person can retain the information provided
3. If the person can understand and weigh up the information relevant to this decision
4. If the person can communicate their decision in any way

Oesophageal dysphagia history taking

HISTORY FOR SHOULD BE DIVIDED WHEN MAKING THE DIAGNOSIS INTO EITHER

1. SOLIDS ONLY or SOLIDS AND LIQUIDS
2. INTERMITTENT or PROGRESSIVE

SOLIDS ONLY suggests mechanical obstruction, whereas SOLIDS AND LIQUIDS suggests a neuromuscular cause.


Causes


SOLIDS ONLY and INTERMITTENT

• Lower oesophageal ring

SOLIDS ONLY and PROGRESSIVE

• Cancer
• Peptic stricture

SOLIDS AND LIQUIDS and INTERMITTENT

• Diffuse oesophageal spasm

SOLIDS AND LIQUIDS and PROGRESSIVE

• Scleroderma
• Achalasia

Investigations in respiratory medicine

Bedside tests

 

Sputum examination

• Collect a good sample and send it for microscopy (Gram stain and auramine/ZN stain), culture and cytology
• Clear and colourless (chronic bronchitis)
• Yellow-green (pulmonary infection)
• Red (haemoptysis)
• Black (smoke, coal dust)
• Frothy white-pink (pulmonary oedema)

 

Peak expiratory flow (PEF)

• Maximal forced expiration through a peak flow meter
• Correlates well with FEV1 as an estimate of airway calibre but is more effort-dependent
   

Pulse oximetry

• Non-invasive assessment of peripheral O2 saturation
• Worry if less than or equals to 80%, unless it is normal in that patient (e.g. COPD)
• Check ABG
• Erroneous readings: poor perfusion, motion, excess light, skin pigmentation, nail varnish, dyshaemoglobinemia and carbon monoxide poisoning

Arterial blood gas (ABG) analysis

• Heparinised blood taken from the radial branch or femoral artery
• pH, PaO2 and PaCO3 are measured using an automatic analyser
• pH normal 7.35 to 7.45
• PaO2 normal 10.5 to 13.5kPa
• PaCO2 normal 4.5 to 6.0 kPa
• Type 1 respiratory failure (respiratory compensation
• Type 2 respiratory failure (no respiratory compensation)
 

Alveolar-arterial O2 concentration gradient

• Normal range 0.2 - 1.5kPa aged 25 years and 1.5 - 3.0 kPa aged 75 years
• High - problem with O2 transfer
• Low - hypoventilation

Spirometry

• Measures lung volumes
• FEV1 and FVC
• Objective defect (e.g. asthma, COPD)
• FEV1/FVC ratio is <75%
• Restrictive defect (e.g. pulmonary fibrosis, sarcoidosis, pleural effusion, connective tissue diseases, neuromuscular problems, interstitial pneumonias, obesity)
• FEV1/FVC ratio is 75% and above

 



 

Further investigations

 

Lung function tests

Radiology

Fibreoptic bronchoscopy

Bronchoalveolar lavage

Lung biopsy

Surgical procedures



Aphasia, Dysarthria, Dysphasia, Dyslexia etc.

As a general rule, a(something) means the COMPLETE absence of, whereas dys(something) is merely a DISORDER of.

Aphasia - Total absence of ability to form speech or language

Dysphasia - Disorder of language

Receptive Dysphasia - Difficulty in comprehension

Expressive Dysphasia - Difficulty in putting words together to make meaning

Dysarthria - Disorder of speech

Agraphia or dysgraphia - Disorder of writing

Acalculia or dyscalculia - Inability to manipulate numbers

Dyslexia - Difficulty reading

Flow of CSF in the brain

Cerebrospinal fluid is produced by modified ependymal cells in the choroid plexus present in almost all components of the ventricular system

This is the order of flow in the brain:

1. Ventricle: Right lateral ventricle and Left lateral ventricle
2. Passage: Interventricular foramen (Foramen of Monro)
3. Ventricle: Third ventricle
4. Passage: Cerebral aqueduct (Aqueduct of Sylvius)
5. Ventricle: Fourth ventricle
6. Passage: 2x Foramen of Luschka (Lateral apertures) and 1x Foramen of Magendie (Medial aperture)
7. Spinal cord: Subarachnoid space of the spinal cord
8. Passage: Arachnoid granulations or Lymphatics
9. Circulation: Venous sinuses or Lymphatics

3 screening questions for musculo-skeletal disease

1. Are you free of any pain or stiffness?
2. Can you dress yourself alright?
3. Can you manage stairs?

Biliary tree

Start from either LIVER or GALL BLADDER


Liver

• Right hepatic duct
• Left hepatic duct

Gall bladder

• Cystic duct

1. The right hepatic duct and the left hepatic duct join to form the common hepatic duct
2. The common hepatic duct joins with the cystic duct to form the common bile duct
3. The common bile duct joins with the pancreatic duct and exit through hepaticopancreatic ampulla (Sphincter of Oddi) in the 2nd part of the duodenum

OSCE revision: Explaining a CT head scan

Introduction

Introduction

• Introduce and identify yourself
• Patient's full name, age, date of birth and preferred name
• Obtain consent to interview

Understanding

• Take a brief history
• Ascertain if the patient knows what a CT scan is and why she needs it

Concerns

• Elicit concerns based on pre-conceived ideas  

Explaining

CT scan

• Clarify what a CT scan is
• "It stands for Computerised Tomography. A CT scan uses X-rays to produces images of the body. The images are produced from data which the scanner acquires and are subsequently turned into cross-sectional images of the body, much like slices in a loaf of bread."

Procedure

• Stop eating and drinking 2 hours before the scan
• Looks like a giant washing machine (or giant doughnut)
• Will be placed inside
• May feel claustrophobic
• Scanning is painless and should take around 10 minutes
• When in the room will be left alone
• Will be able to speak to the operator through an intercom system
• May need IV contrast (harmless dye), so check for allergies

Safety

• Generally safe
• Lowest practical dose of radiation (since it is made up of multiple X-rays)
• Benefits outweigh risk of exposure

Risks

• Not recommended for pregnant women

 

Closing up

Understanding

• Check whether the patient has understood what had been explained

Questions

• Encourage the patient to ask questions and deal with them appropriately
• Ask about concerns

Summary

• Summarise everything

Consent

• Take consent

Respond

• Acknowledge patient's feelings and react positively to them

Adapted from: MasterPass

OSCE revision: Explaining an MRI scan

Introduction

 

Introduction

• Introduce and identify yourself
• Patient's full name, age, date of birth and preferred name
• Obtain consent to interview

 

Understanding

• Take brief history
• Ascertain if patient knows what an MRI scan is and why it is needed

 

Concerns

• Elicit concerns based on pre-conceived ideas
 

 

Explaining

 

MRI scan

•  Clarify what an MRI scan is
• "It stands for magnetic resonance imaging and is a non-invasive way of getting pictures of the human body. The process uses a magnetic field to obtain accurate pictures of an area and does no involve X-rays."

 

Procedure

• Allowed to eat and drink freely before
• Placed into a large tube
• May feel claustrophobic
• Painless procedure
• About 30 minutes (longer can be up to an hour)
• Noisy, but will be provided with earplugs
• Will be left alone in the room but will interact with operators through intercom
• May need IV contrast (harmless dye), and check for allergies

 

Safety

• Extremely safe
• No risk of repeated exposure unlike CT, since X-rays are not involved 

 

Risks

• Check that there are no contraindications (metallic parts)
• No pacemakers, surgical clips, metallic fragments in eyes (CT to confirm absence if in question) or metallic heart valves unless otherwise certified

 

 

Closing up

 

Understanding

•  Check whether the patient has understood what had been explained

 

Questions

• Encourage the patient to ask questions and deal with them appropriately
• Ask about concerns

 

Summary

•  Summarise everything

 

Consent

•  Take consent

 

Respond

•  Acknowledge patient's feelings and react positively to them

 

 

Adapted from: MasterPass

Schmorl's nodes

Radiology

Schmorl's nodes or nodules are protrusions of the cartilage of the intervertebral disc through the vertebral body endplate and into the adjacent vertebra

They are detected on plain X-ray films

Problems

• May contact the marrow of the vertebra and lead to inflammation
• Protrusions are associated with necrosis (don't know if necrosis is caused by)

Mesial temporal sclerosis

Neuroradiology

Mesial temporal sclerosis (hippocampal sclerosis) is a specific pattern of hippocampal neuron cell loss, and is divided into three categories based on 'sectors' affected.

• CA1 and CA4
• CA4 alone
• CA1 to CA4

Characteristics

• Hippocampal atrophy and gliosis
• Increased T2 signal
• May occur with other temporal lobe pathologies
• Most common feature in temporal lobe epilepsy

ECG abnormalities

Sinus tachycardia

• Rate >100
• Causes
• Anaemia
• Anxiety
• Exercise
• Pain
• Sepsis
• Hypovolaemia
• Heart failure
• Pulmonary embolism
• Pregnancy
• Thyrotoxicosis
• Beri beri
• CO2 retention
• Autonomic neuropathy
• Sympathomimetics e.g. caffeine, adrenaline, and nicotine

Sinus bradycardia

• Rate <60
• Causes
• Physical fitness
• Vasovagal attacks
• Sick sinus syndrome
• Acute MI (inferior most likely)
• Hypothyroidism
• Hypothermia
• Increased intracranial pressure
• Cholestasis
• Drugs e.g. Beta blockers, digoxin, amiodarone, verapamil

 AF

• Causes
• IHD
• Thyrotoxicosis
• Hypertension

1st and 2nd degree (Mobitz I/II) heart block

• Causes
• Normal variant
• Athletes
• Sick sinus syndrome
• IHD
• Acute carditis
• Drugs (digoxin, Beta-blockers)

3rd degree complete heart block

• Causes
• Idiopathic (fibrosis)
• Congenital
• IHD
• Aortic valve calcification
• Cardiac surgery/trauma
• Digoxin toxicity
• Infiltration (abscesses, granulomas, tumours, parasites)

Q waves

• Pathological Q waves are usually >0.04s wide and >2mm deep
• Causes
• Infarction
• Acute MI

ST elevation

• Causes
• Normal variant (high take-off)
• Acute MI
• Prinzmetal's angina
• Acute pericarditis (saddle-shaped)
• Left ventricular aneurysm

ST depression

• Causes
• Normal variant (upward sloping)
• Digoxin (downward sloping)
• Ischaemic (horizontal)
• Angina
• Acute posterior MI

T inversion

• V1-V3
• Normal (Blacks and children)
• Right bundle branch block (RBBB)
• Pulmonary embolism
• V2-V5
• Subendocardial MI
• HCM
• Subarachnoid haemorrhage
• Lithium
• V4-V6 and aVL
• Ischaemia
• LVH
• Left bundle branch block (LBBB)

Myocardial infarction

• Within hours, the T wave may become peaked and ST segments may begin to rise
• Within 24 hours, the T wave inverts, as ST segment elevation begins to resolve
• ST elevation rarely persists, unless a left ventricular aneurysm develops
• T wave inversion may or may not persist
• Within a few days, pathological Q waves begin to form
• Q waves usually persist, but may resolve in 10%
• The leads affected reflect the site of the infarct
• Inferior (II, III, aVF)
• Anteroseptal (V1-V4)
• Anterolateral (V4-V6, I, aVL)
• Posterior (V1-V2, tall R)
• Subendocardial (No Q waves, ST and T changes present)

Pulmonary embolism

• Sinus tachycardia is commonest
• There may be RAD, RBBB, right ventricular strain pattern (R-axis deviation, dominant R wave and T wave inversion/ST depression in V1 and V2, leads II, III and aVF may show similar changes)
• Rarely, the 'SIQIIITIII' pattern occurs: deep S waves in I, pathological Q waves in III, inverted T waves in III

Metabolic abnormalities

• 'Digoxin effect': ST depression and inverted T wave in V5-6 (reversed tick)
• In digoxin toxicity, ANY arrhythmia can occur (ventricular ectopics and nodal bradycardia are common)
• Hyperkalaemia: Tall, tented T wave, widened QRS, absent P waves, 'sine wave' appearance
• Hypokalaemia: Small T waves, prominent U waves
• Hypercalcaemia: Short QT interval
• Hypocalcaemia: Long QT interval, small T waves

Radiology OSCE tips and checklists

Presentation tips

• Pay attention to the clinical details
• Have lines prepared
• Make brief comment on image quality
• Describe the 'obvious' abnormality first
• Continue systematically
• Describe things that you are unsure of and come back to them only if you think that they are relevant
• Check the review areas
• Summarise in one sentence with a link to the clinical scenario
• Suggest immediate management
• Observe examination etiquette

Chest X-ray check list

• Correctly identifies patient
• Correctly notes time and date
• Correctly states AP or PA
• Comments on image quality
• Comments on medical devices
• Assesses lung expansion
• Accurately assesses heart size
• Comments on salient abnormalities using correct terminology
• States correct diagnosis
• Offers appropriate management plan
• Requests appropriate next image

Abdominal X-ray check list

• Correctly identifies patient
• Correctly notes time and date
• Comments on image quality
• Comments on medical devices
• Assesses bowel gas pattern
• Assesses soft tissues and bone
• Comments on abnormal calcification
• Offers appropriate management plan
• Requests appropriate next image (Erect chest X-ray)

Adapted from: http://radiologymasterclass.co.uk

Chest x ray anatomy

Visible structures

• Trachea
• Hila
• Lungs
• Diaphragm
• Heart
• Aortic knuckle
• Ribs
• Scapulae
• Breasts
• Stomach

Invisible or obscured structures

• Sternum
• Pleura
• Oesophagus
• Fissures
• Spine
• Aorta

Trachea and major bronchi

• The large airways contain air and are therefore less dense (blacker) than surrounding tissue
• The trachea should be central, but may be displaced slightly to the right since it passes to the right of the aorta
• The trachea and bronchi are visible, and branch at the carina

Hilar structures

• Each hilum contains major bronchi and pulmonary vessels
• Lymph nodes on each side are not visible unless abnormal
• Left hilum is often higher than the right due to the presence of the heart on the left side
• Position, size, and density of hila are important
• If position is changed, has it been pushed or pulled?
• If size and density are both increased then it is indicative of pathology

Lung zones

• Lung are assessed and described by dividing them into upper, middle, and lower zones (not lobes)
• Compare left to right, and normal to abnormal
• Be careful of pathologies that give rise to bilateral abnormalities
• Note that the lower zone extends below diaphragm due to the diaphragm's dome shape

Pleura and pleural spaces

• The pleura and pleural spaces are only visible when abnormal
• Lung markings should reach the thoracic wall
• Normal invisible pleura
• Trace around the entire edge of the lung (starting and ending at the hila), paying attention to where abnormalities are most seen
• Is there pleural thickening, pneumothorax or effusion?

Lung lobes and fissues

• Left lung has two lobes and an oblique fissue (seen on lateral view)
• Right lung has three lobes and both a horizontal (seen on normal (AP/PA) view) and an oblique fissure (seen on lateral view)
• Each lobe has its own covering of pleura
• Fissures are important because some diseases are confined to a certain extent within lobes
• May have azygous fissure (azygous vein runs within it)

Costophrenic angles and recesses

• Costophrenic angles are limited views of the costophrenic recess
• They should be sharp on frontal view (although when they are blunt it isn't always pleural effusion)
• Formed by lateral chest wall and dome of each diaphragm

Diaphragm

• The hemidiaphragms are domed structures
• Each hemidiaphragm should be well defined
• The left hemidiaphragm should be visible behind the heart
• The hemidiaphragm contours do not represent the lowest part of the lungs
• Liver beneath the right
• Stomach (gastric bubble visible) beneath the left

Heart size and contours

• Cardiothoracic ratio (CTR) = Cardiac width : Thoracic width
• Heart size is assessed as CTR (>50% is abnormal but only applicable to PA)
• Cardiac contours
• Right (Right atrium)
• Left (Left ventricle)

Mediastinal contours

• Middle mediastinum contains the heart
• Aortic knuckle
• Represents the left lateral edge of the aorta as it arches backwards over the left main bronchus and pulmonary vessels
• Displacement or loss of definition may mean aneurysm or adjacent lung consolidation
• Aorto-pulmonary window
• Lies between arch of the aorta (superior) and pulmonary arteries (inferior)
• Abnormal enlargement of lymph nodes can be seen here
• Right para-tracheal stripe
• From the level of the clavicles to the azygous vein the right edge of the trachea is seen as a thin white stripe
• If this stripe is abnormally thickened (more than or equals to 3mm), it may represent a paratracheal mass or an enlarged lymph node

Soft tissues

• These need to be assessed on every chest x ray
• Thick soft tissue may obscure underlying structures
• Black within soft tissue may represent gas
• Breast asymmetry is common and should not be mistaken for pathological soft tissue
• Nipple markings may be seen but care should be taken that they are not pathological lung nodules
• Pseudo-blunting of the costophrenic angle may be due to breast, malposition, etc.
• Soft tissue fat appears less dense and therefore darker
• These are usually regular as opposed to irregular pockets of black as is in the case of surgical emphysema

Bones

• These need to be assessed on every chest x ray
• They are also helpful in assessing the quality of the x ray
• Look for abnormalities of single bones and diffuse bone disease
• Clavicles clearly seen on x ray
• Spinous processes of vertebra should lie midway between the medial ends of the clavicles (if not then the patient is rotated)
• Check of metastases in bones especially in well-defined structures such as the clavicle, scapula, and humerus
• Ribs are important in assessing the inspiratory effort made by the patient
• Anteriorly there should be 5-7 ribs
• More than 7 ribs and flattening suggests lung hyper-expansion
• Adequate penetration when spine can be seen through the heart

Approach to ECG

Confirm details

• Name
• Age
• ECG date

Rate

• 25mm/s standard (0.04s per small square, 0.2s per big square)
• 300 divide by number of big squares between each R-R interval

Rhythm

• Intervals should be equal (card method)
• Different rates either 100% irregular (AF) or multiples (varying block)
• Sinus rhythm  is P wave followed by QRS 

Axis

• Normal -30 to +90 (Complexes in leads I and II are usually both normal)
• Left axis deviation -30 to -90
• Left anterior hemiblock
• Inferior MI
• VT from LV focus
• Some WPW syndromes
• Right axis deviation +90 to +180
• RVH
• PE
• Anterolateral MI
• Left posterior hemiblock
• Some WPW syndromes

P wave

• Normally one before QRS complex
• Absent
• AF
• Sinoatrial block
• Junctional (AV nodal) rhythm
• Dissociated from QRS
• Complete heart block
• Bifid
• P mitrale (left atrial hypertrophy)
• Peaked
• P pulmonale (right atrial hypertrophy)
• Pseudo P pulmonale (K+ lowered) 

PR interval 

• Start of P to start of QRS
• Normal 0.12s to 0.2s (3-5 small squares)
• Prolonged
• Delayed AV conduction (1st degree heart block)
• Shortened
• Unusually fast AV conduction down an accessory pathway (e.g. WPW)

QRS complex

• Normal less than 0.12s
• > or = 0.12 suggests ventricular conduction defects (e.g. bundle branch block) 
• Large complexes (vertical) suggest ventricular hypertrophy
• Q wave
• <0.04s wide and <2mm deep (although V5, V6, AVL and I would be normal)
• Pathological seen a few hours after acute MI

QT interval

• Start of QRS to end of T
• Calculate QTc because it varies with rate
• QTc = QT / square root of RR = 0.38s to 0.42s
• Prolonged
• Acute MI
• Myocarditis
• Bradycardia (e.g. AV block)
• Head injury
• Hypothermia
• U&E imbalance (decreased K+, Ca2+ and/or Mg2+)
• Congenital (Romano-Ward and Jervell-Lange-Nielson syndromes)
• Drugs
• Sotalol
• Quinidine
• Antihistamines
• Macrolides (e.g. erythromycin)
• Amiodarone
• Phenothiazines
• Tricyclics

ST segment

• Usually isoelectric
• >1mm elevation = Infarction
• >0.5mm depression = Ischaemia

T wave

• Normally inverted in AVR, V1 and occasionally V2
• Abnormal if in I,II,V4,V5,V6
• Peaked in hyperkalaemia
• Flattened in hypokalaemia

J wave

• Abnormal peak right after S wave
• Hypothermia, subarachnoid haemorrhage, hypercalcaemia

X-ray basics

Formation:

X-rays are formed in an X-ray tube when:

1. A high-energy electron (an accelerated electron) knocks and displaces an inner shell low-energy electron (from tungsten nuclei in the tube anode).
2. This causes an outer shell electron (from same tungsten nuclei) to take the place of the inner shell electron.
3. The resultant energy loss as a result of this electron's shift from the outer shell to the inner shell is in the form of the X-ray itself.

Principles:

• X-rays travel in straight lines
• Body parts further away from the detector are magnified compared with those that are closer
• Magnification can be helpful in localising abnormalities
• Relevance to AP, PA, Lateral etc. (Left Lateral means that the Left is closer to detector and is hence LESS magnified than the right)

Tissue densities:

• An X-ray image is a map of X-ray attenuation (greater attenuation = more blockage of the beam)
• Attenuation is variable depending on the density and thickness of tissues
• Descriptions can be done in terms of density
• Less dense = Darker
• More dense = Brighter
• In increasing density (Darker to Brighter)
• Air
• Fat
• Soft tissue
• Bone
• Metal

X-ray safety:

• X-rays are potentially harmful
• Requests for radiological examinations should be clinically justified
• The inverse square law
• The strength of the X-ray beam is inversely proportional to the square of the distance from the source
• Standing back double the distance will therefore quarter the dose of radiation

Cardiovascular symptoms

Chest pain

Serious causes

• MI
• Dissecting aortic aneurysm
• Pericarditis
• Pulmonary embolism

Description

• Character
• Constricting (angina, oesophageal spasm, anxiety)
• Sharp (pleura, pericardium)
• Prolonged dull central chest pain (MI)
• Radiation
• Shoulder/both arms or epigastric (cardiac ischaemia)
• Instantaneous, tearing, interscapular or retrosternal (aortic dissection)
• Precipitants
• Cold, exercise, palpitations or emotion (cardiac or anxiety)
• Food, lying flat, hot drinks, alcohol (oesophageal spasm but may still be cardiac)
• Relieving factors
• Rest of GTN (cardiac)
• Antacid (GI)
• Leaning forward (pericarditis)
• Associations
• Dyspnoea (cardiac pain, pulmonary emboli, pleurisy, or anxiety)
• Nausea, vomiting, or sweating (MI)
• Chest pain with tenderness (Tietze's syndrome)
• Pleuritic pain
• Pain exacerbated by inspiration 
• Inflammation of pleura
• Differentials include musculoskeletal (fractured rib) or subdiaphragmatic pathology (gallstones)
• Acutely ill patients
• Admit to hospital
• Check pulse and BP in both arms
• JVP
• heart sounds
• Examine legs for DVT
• Give O2 by mask
• IV line
• Relieve pain (morphine 5-10mg IV slowly 2mg/min + antiemetic)
• Cardiac monitor
• 12 lead ECG
• ABG
• Think about: dissection, zoster, ruptured oesophagus, cardiac tamponade with shock, opiate addiction

Dyspnoea

• Causes
• LVF
• Pulmonary embolism
• Any respiratory cause
• Anxiety
• History
• SOB at rest or exertion
• Exercise tolerance
• Episodic or triggered by lying flat
• Heart failure: orthopnoea (pillows at night), paroxysmal noctural dyspnoea (waking up at night gasping for breath), and peripheral oedema
• Pulmonary embolism: acute onset of dyspnoea and pleuritic chest pain, risk factors for DVT

Palpitations

• Causes
• Ectopics
• AF
• SVT
• Ventricular tachycardia
• Thyrotoxicosis
• Anxiety
• Phaeochromocytoma
• History
• Previous episodes
• Precipitating/relieving factors
• Duration of symptoms
• Chest pain
• Dyspnoea
• Dizziness
• Patient's pulse?

Syncope

• Cardiac or CNS events
• Vasovagal 'faints' are common (pulse decreased, pupils dilated)
• Cardiac cause: Chest pain, palpitations, dyspnoea
• CNS cause: Aura, headache, dysarthria, limb weakness
• Ask observer:
• Was there pulse?
• Limb jerking?
• Tongue biting?
• Urinary incontinence?
• Rapid (arrhythmia)?
• Prolonged (seizure)?

Cardiovascular health

Ischaemic heart disease (IHD) is the most common cause of death worldwide.


Preventing IHD

• Exercise (Decreased BP, Increased HDL)
• Stopping smoking
• Eating healthily
• Avoid obesity
• Moderate alcohol drinking

Smoking cessation

• Psychological
• Advice congruent to patient's beliefs about smoking
• Enumerate advantages to increase motivation
• Invite patient to choose a date to stop
• Throw away all accessories
• Pharmacological
• Nicotine gum
• Varenicline (oral selective nicotine receptor partial agonist) 
• Bupropion (increases dopamine in mesolimbic system and via noradrenergic effects in the locus ceruleus)

Risk equation calculation

• Age
• Sex
• BMI
• Cholesterol/HDL
• FHx
• BP
• Smoking
• PMHx (IHD, rheumatoid arthritis, AF, hypertension, renal disease)
• Social deprivation (via postcode)

What this blog is about.

In my attempt to prepare for the finals, I am setting up this blog. There are two types of entries. The first is free text, and the second is the characterisation of a disease based on "Dressed In a Surgeons Gown A Physician Might Make Progress"

D - Definition

I - Incidence

S - Sex

G - Geography

A - Aetiology

P - Pathogenesis

M - Macroscopic pathology

M - Microscopic pathology

P - Prognosis

Treatment options may be added



This was adapted from: http://www.revise4finals.co.uk/medicine/mnemonics/r4f_pastest_mnemonics.pdf


Thank you, good luck, and have fun!