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Med in Small Doses - Ventricular Tachyarrhythmias

2012-02-22T13:17:00.002+10:00

This post is on some common and important Ventricular Tachyarrhythmias (e.g. Ventricular Fibrillation). See Cardiac Arrhythmias for a complete overview. A Quick Guide to ECG will also give you tips on how to approach an ECG.

Typically Board Complex (QRS>0.12)

General Approach to the acute management of Ventricular Tachyarrhythmias is ACLS or Advanced Life Support (ALS). VF & pVT are both shockable rhythms.

VF (V-fib)
Most serious. Cardiac Output = 0.
VF is a medical emergency that requires prompt BLS interventions.

Key ECG Features

Irregular rhythm
No measurable rate
Loss of P Waves
No discernible QRS complex

VF via ECGPedia

VT
Most common cause is myocardial ischaemia or scarring following an AMI. Pulseless VT is a major threat to life.

Key ECG Features

QRS Regular (occasionally slightly irregular) and wide (>0.12s)
Ventricular rate = 150 - 250 bpm
P Waves do link up with QRS Complexes
Hard to seperate QRS Complex and T Waved

VT via ECGPedia

Ventricular tachycardia: treatment LAMB:

L idocaine

A miodarone

M exiltene/ Magnesium

B eta-blocker

Consider DC Cardioversion (repeat up to 3 times).

Pulseless VT: Commence ALS. Early defibrillation is the priority.

Torsades

Torsades de pointes, or simply torsades, is a French term that literally means "twisting of the points." Wikipedia

Can progress to VF.

Key ECG Features

Regular (mostly)
Rotation of the heart's electrical axis by at least 180°
Ventricular rate = 150-300 bpm

Torsades adapted from Wikipedia

RFs: FLASH

F Familial Long QT syndrome

L eft Ventricular Hypertrophy

A cidoisis / Antiarrhythmics (Class III)

S low heart rate / SAH

H ypos (e.g. Hypokalemia, Hypocalaemia, Hypomagnesaemia, Hypothermia)

Tx: Withdrawal of the offending agent, infusion of Mg2+ sulfate, antiarrhythmic drugs, and electrical therapy as needed.

Med in Small Doses - Schizophrenia

2012-02-15T12:00:00.000+10:00

This is part of the Med in Small Doses series, which aims to give you a snapshot of a disease or disorder. For information about the series, or common abbreviations click here.

International Prev. 0.5-1.0%. M = F. Males have worse outcomes.

CFs: A useful mnemonic is HD N CD. Think High Definition And CD.

H: hallucinations

D: delusions

N: Negative symptoms (flat affect, social withdrawal, poverty of speech)

C: catatonic or grossly disorganized behavior

D: Disorganized speech

Positive

Hallucinations
Delusions
Disorganised behaviour
Thought disorder
Catatonia

Negative

Social withdrawal
Emotional flattening
Anhedonia
Reluctance to perform everyday tasks

PATHO: Genetic Factors (accounts for ~80%) & Environmental Factors play a role.

Cortex – atrophy, larger ventricles &↓temporal lobe volume

Limbic system – ↓ size of amygdala, hippocampus and parahippocampal gyrus.

More marked on left side.

Thalamus – ↓ volume

Dx Criteria:

Psychotic symptoms for over a month
Impaired psychosocial function
Continuous signs of illness for over 6 months
Not explained by prominent mood disorder

Tx: Long-term planning & Family Education are important aspects.

Antipsychotics - Typical (e.g. Haloperidol & Flupenthixol) & Atypical (e.g. Clozapine & Risperidone)

Mood stabilisers (e.g. Lithium - 'Gold Standard'; or Clozapine) & Psychosocial therapy

Med in Small Doses - SVT Tachyarrhythmias

2012-02-08T10:30:00.000+10:00

This post is on some common and important SVT/Atrial Tachyarrhythmias (e.g. Atrial Fibrillation). See Cardiac Arrhythmias for a complete overview. A Quick Guide to ECG will also give you tips on how to approach an ECG. Remember Bundle Branch Blocks effect ECG interpretation.

Typically Narrow complex (QRS<0.12)
EXCEPTION: SVT + Bundle Branch Block cause Board complex.

Supraventricular tachycardia: causes SNAP

S inus tachy

N odal tachy

A fib

P aroxysmal atrial tachy

Irregular
Atrial Fibrillation (AF): most important arrhythmia. irregular, irregular pulse. Loss of P waves.

Adapted from AFib by J.Heuser

RFs: IHD, HTN, Chronic EtOH use, cardiomyopathy, Congenital HD, Valvular lesions

Causes PIRATES:

P ulmonary: PE, COPD

I atrogenic

R heumatic heart: mirtral regurgitation

A therosclerotic: MI, CAD

T hyroid: hyperthyroid

E ndocarditis

S ick sinus syndrome

Complications: ↓ CO, embolic stroke, ↑ ventricular response.

Tx: Rate control (Beta-blockers, CCB, digoxin), rhythm control (DC cardioversion, amiodarone, flecainide) & anticoagulation.

AF < 48h – Cardiovert immediately with a bit of heparin
AF > 48h – Look for a clot. Rhythm control or rate control + anticoagulation.

Management ABCD

A nti-coagulate

B eta-blocker to control rate

C ardiovert

D igoxin

Multifocal atrial tachycardia (MAT): P-waves of at least 3 different morphologies that all fall before irregular, narrow QRS complexes.

Regular
Sinus Tachycardia (rate > 100 bpm)
Causes: exercise, pain, anxiety, hypovolaemia, PE, hyperthyroidism.
Management Priority: Search for a cause.

AVNRT: nodal problem.

Most common regular SVT tachycardia.
Females > Males

AVRT: accessory pathway.

Most common WPW. Short PR intervals. Delta waves.

General Tx: Valsalva manoeuvre, Carotid Sinus Massage (CSM), ocular pressure. Adenosine, DC cardioversion.

What would be the ideal app for Medical Students?

2012-02-07T10:30:00.000+10:00

Medical students are one of the highest user groups of smart phones. With the use of Smart phones (e.g. iPhone, Android, Windows) medical students have access to thousands of resources right at their fingertips. Whether it be native apps such as, Medscape, Epocrates, even mobile textbooks like Oxford Handbook of Clinical Medicine or web apps. There are a huge range of options available. Each with their own degree of usefulness (some apps that are still my favourites are listed in Top Medical Apps for the iPhone).

If you want to skip the Back Story which contains a degree of fluff, then head on straight to The Situation.

The Back Story
Many universities globally have developed an app for their students and staff. These are generally broadly targeted, with features such as timetables, news, events, contacts and so on. Some are good, whilst some are just plain bad or fail to provide enough services. As far as I'm aware though, there are hardly any apps developed specifically by a university, for their medical program.

Which leaves me thinking that there is a huge wasted opportunity.

As some of you may know I developed my own unofficial app for my medical school, known as UQ Med Lite. I developed this app, mainly because I felt there was a huge gap in what the school was offering. I'm a regular user of my iPhone, and I found that daily tasks like checking my timetable were a hassle under the existing system.

So with a few nights learning the basics of coding I developed my app. The original app solely acted as a portal, and simple provided links to important websites or contacts. I quickly realised that with all the materials I had built up on this blog, I could quite easily turn it into a quick reference tool as well. So that's what I did.

Now the app provides a range of features summarised below.

MBBS Timetable
Clinical Skill Guides (History Taking & Examination)
Drug List (Drugs needed to know by Year 3)
Pathology (Robbin's Pathology, UQ Resources & related resources)
Inbuilt access to mobile versions of Up to Date, Pubmed & Access Medicine
Help you get connected. (Set-up Eduroam profile, mobile email & much more)
UQ's My Library and Library resources for the MBBS Program
Information on UQ's Clinical Schools with maps.
Information on the School of Medicine and related student societies.

While in no means perfect, and definitely limited by my technical skill and time I'm willing to put in, it provides a basic point of connection and reference for UQ's medical students.

The Situation
Like many people I would have rather seen my own medical school make an app. Unfortunately, they did not, so I went ahead and gave it a crack. But now I ask you this,

If your medical school had an app what would you like to see in it?

It can be anything that comes to your mind.

The Problem of Healthcare in Rural Australia

2012-02-06T12:36:00.002+10:00

Well a lot has been happening recently concerning Rural Healthcare (or maybe I'm just paying more attention) and I thought I would just shed some light. I do not claim to be an expert this area, and I certainly do not have all the facts, but I hope this post gives you a good snapshot of the current situation.

In part one, we will take a general look at the rural healthcare system as it stands. In part two, I'll take you through some of the issues I believe are particular pertinent to medical students and doctors. Which are part of the larger solution to Rural Healthcare.

The System

The healthcare situation in Rural Australia has long been dire. But it's not just Australia that is in trouble. Countries all over the world are finding that maldistribution of the workforce is one of the main issues limiting access to primary health care (World Health Organization 2006, 2010). Rural Australia has a widely dispersed population in a geographically and culturally varied region.

So what can we do about it?

Well the Australian solution for the past decade or so has been to send all the new incoming international doctors out to the bush. While in some cases this tactic has worked fine, there are many cases where both the doctor and the community are left short-changed. Dr Hambleton from the AMA noted,

''What we ask of our international colleagues is mind-boggling, because rural practice is challenging for any graduate, let alone someone unfamiliar to the country way of life,''.

In other words a flimsy band-aid solution at best.

Now here's a shocking statistic, 41% of the rural and remote Australian medical workforce in 2007 trained overseas (Australian Government Department of Health and Ageing 2008).

On the consumer-side of things, a recent report noted that, rural residents miss out on ~6 million GP visits, they would otherwise have, if they had the same access to health-care as their metropolitan counterparts. (Access to general practitioner services amongst Rural Australians, 2012).

Interestingly they also noted;

Parity is an insufficient goal and disadvantaged persons and underserved areas require greater access to health services than the well served metropolitan areas due to their greater poverty and poorer health status.

In other words, as the Australian and State governments have let the situation get so bad, they now need to invest more if they were to ensure health equality across Australia.

The most recent figures from the Australian Institute of Health and Welfare show there were 4600 excess deaths in rural Australia from 2004 until 2006, compared to major cities, and the most common causes were heart disease, circulatory disease, chronic obstructive pulmonary disease, motor vehicle accidents and suicide.

There are many other aspects of the Rural Healthcare situation that can be explored, which I will not cover here. However, if you are particularly interested in Mental Health and the Better Access program, you should check out Alison Fairleigh's blog which delves into these topics. Alternatively follow the #RuralMH discussions on twitter.

Education & Encouragement

The current solution to Rural Healthcare is not working, so it's time that the policy makers took another look and re-considered their approach. There are many things which could be altered to improve the situation, but two topics I'm going to cover are education and encouragement.

Student Diversification
Medical education is one area that has a chance of addressing the rural workforce shortages. Government policies were made a while back that encouraged medical schools to intake a certain proportion of rural students. The idea being, that these students would be more likely to return to their rural communities for professional practice. Medical Schools like JCU with higher rural intakes, have demonstrated that a larger number of their medical students end up in rural practice as Doctors.

The biggest issue here: Not all medical schools have been adhering to the rules.

Schools fail on bush doctor target

Thankfully, some of the worst offenders have now begun putting in place entrance pathways that ensure there are a larger number of rural students within their course. From next year the University of Queensland which was previously one of the worst offenders, has set up a separate rural entry quota of 25% for its medical school. Meaning that rural applicants will only have to compete amongst themselves for those places (Med schools to ease rural student entry).

Stay tuned for more to come on these two areas in part 2.

Image: Adapted from Rural Southern Story County by cwwycoff1.

Med in Small Doses - Cardiac Arrhythmias Overview

2012-01-31T11:00:00.000+10:00

Disorder of heart rate (slow: bradycardia or fast: tachycardia) or rhythm. Can occur at Sino-atrial node, Atria or Ventricles.

Can be broadly split into tachyarrhythmias and bradyarrhythmias.

PATHO: Problems with the Heart's electrical conduction system.

Causes: (STRIDES)

S tructural Abnormalities

T hyroid Disease

R heumatic Heart Disease

I schaemia

D rugs (e.g. digoxin, CCB, B-Blockers)

E lectrolytes (e.g. K+, Ca2+, Mg2+)

S ocial Drugs (e.g. Caffeine, Cocaine)

CFs: Asymptomatic, Palpitations, Sweating, De-compensated (Low BP, LoC, Chest pain, pulmonary oedema), Syncope, Dyspnoea, Sudden Death.

Ix: Best investigation is ECG. Note Bundle Branch Blocks effects ECG interpretation. Read a Quick Guide to ECG to understand the basics behind reading and interpreting ECGs.
FBC and U&E. Holter monitor, echocardiogram & coronary angiography.

General Tx: Please note that these are very basic principles. Please seek the appropriate medical advice or the specific regimen that goes with certain arrhythmias.Lifestyle management including management of some modifiable causes, medications, electrical therapy (defibrillation, cardioversion, or pacing), insertion of pace-maker.

Asystole: treatment "Have some asystole "TEA":

T ranscutaneous pacing

E pinephrine
A tropine

Overland to Endeavour

2012-01-26T10:00:00.000+10:00

Usually I keep this blog away from personal adventures, and stick with the facts and figures of medicine. At times however, I feel that there are certain experiences worth sharing. With it being Australia Day, it seemed even more relevant that I share this experience. I had the great opportunity during last December to participate on-board the STS Young Endeavour from Hobart to Sydney. Before I go any further, I'll tell you a bit about the Young Endeavour.

STS Young Endeavour is sail training ship used by the Young Endeavour Youth Scheme for the Youth of Australia. It is operated by the Australian Navy and can include up to 30 youth crew on any single voyage. The aim of the scheme is to build leadership, foster teamwork, develop life-long friendships and create a strong sense of community responsibility.

The vessel is brigantine rigged, with a 32-metre (105 ft) tall mainmast, and ten sails with a total area of 511 square metres (5,500 sq ft).

But first we must go Overland
Before I got to get under-way on that fantastic voyage, I took some time out to explore some of Tasmania's natural treasures, one of them being the Overland Track. The Overland Track is one of Australia's most well known tracks, running 65kms from Cradle Mountain to Lake St Clair. Along this track you will encounter all types of scenery and terrain; from the rocky sides of mountains to waterfalls surrounded by lush rainforest.

It has it all.

I can honestly say I have not been to too many more beautiful or diverse places in the world. The greatest gift I got from the track was its' quietness. I had the opportunity to get away from noise that generally accompanies my day to day life, and allowed it me to reflex on what had occurred throughout the year.

Like everybody, medical students and doctors similarly can get caught up with all the things going on around us. So I add this reminder to you,

Take the time to enjoy the simple things in life and the small pleasures that give you joy, and shed those things which are little more distractions.

Aye Captain
Young Endeavour similarly pushed me to rethink, my attitude towards the world and myself. Each morning we were given many inspirational quotes from the Captain to begin our day. There is one quote for me that really stood out, which we were told right before climbing for our first time to the top of the 32m foremast.

Start by doing what's necessary, then what's possible, and suddenly you are doing the impossible. Francis of Assisi

These simple, yet powerful set of words, can be carried everywhere through your life, which at the end of day I feel can be summed up as;

Give everything a go.

Aside from climbing the foremast the Young Endeavour threw many challenges at me personally and the youth crew team, which I could literally spend hours going in to. So rather than doing that I'll just give you a snapshot of some of my highlights.

Participating in Mawson's 100th Tribute
Stopping in at fantastic locations like Wineglass Bay & Eden
Crossing the Bass Strait entirely on Sail Power
Furling (i.e. tying up) sails during the middle of the night, along the yards
Command Day - Where the Youth Crew take control of Young Endeavour for 24hrs. The Captain kindly reminded before we started that we were responsible for a $22 million ship.
Having a fantastic time with a great bunch of people.

So why am I mentioning all of this?

Well the Ballot is open again for voyages from July to December 2012 and I would like to see as many young Australians as possible have a chance to jump on-board this amazing vessel.

Apply Here

If you are a past Youth Crew or Staff member go to youngendeavouraa.org to stay in the loop and participate in future events.

That's all from me for now. Hope you had a great Australia Day.

Med in Small Doses - Asthma

2012-01-25T10:44:00.000+10:00

This is part of the Med in Small Doses series, which aims to give you a snapshot of a disease or disorder.

Inflamed small airways due to hypersensitivity. Multifactorial – genetics + environmental influences

PATHO: Inflammation (T2H, IL-5, etc) → bronchoconstriction → oedema → ↑ mucus secretion → smooth muscle hypertrophy → damage to epithelium and shedding.

CFs: Classic Triad - Wheeze, Cough (dry, or productive of mucoid or pale yellow sputum), Dyspnoea. Nasal mucosal swelling, ↑nasal secretions

RFs: mnemonic - FEAR UP
F amily history
E czema
A cid reflux
R hinitis (allergic)
U rticaria
P olyps (nasal)

Ix: Chest x-ray, Allergy testing, Eosinophil count

Spirometry: ↓ FEV1/FVC, ↓ PEF, ↓ FVC

The different PFTs:

SPIROMEtry

S pirometry

P EFR

I nhalation tests:

R eversibilty of

O bstruction with beta-agonist

M etacholine challenge

E xhaled NO

Tx & Mgmt: Monitoring & scheduled visits, education and avoid triggers.
Relief vs prevention, B2-Agonists: airway dilation. Glucocorticoids: anti-inflammatory.

Treatment of Status Asthmaticus: (severe acute asthma)

Oxygen
Nebulised salbutamol
IV hydrocortisone
Oral prednisolone

Mnemonic

A drenergics

S teroids

T heophyllines (althouigh not used as much now though)

H ydration

M ask

A ntibiotics if necessary.

Rule of 2's
Treatment needs to be changed if there are more than:

2 uses of relief inhalers per week
2 nocturnal awakenings per month
2 canisters of relief inhaler used per year

For a review of respiratory pathology checkout an Introduction to Respiratory Pathology & Pulmonary Tumours.

Med in Small Doses - Alzhiemer's Disease

2012-01-18T11:00:00.000+10:00

This is part of the Med in Small Doses series, which aims to give you a snapshot of a disease or disorder.

Most common dementia. F>M. 65% of dementia at all ages (K&C). Prevalence doubles every 5 years after age 65. 5-10% familial. Insidious onset.

PATHO: ↓ cholinergic neurons in hippocampus & prefrontal cortex. Amyloid angiopathy. Widened Sulci. Hydrocephalus ex vacuo Medial temporal lobe atrophy.
The cognitive changes in AD follows a characteristic pattern, beginning with memory impairment and progressing to language (naming, comprehension and finally fluency) and visuo-spatial deficits.

Cortical atrophy with neuritic plaques (Aβ) and neurofibrillary tangles (tau). Cleavage by α & γ = normal. Β-secretase + γ → Aβ formation → neurotoxic.

Two Types:
Early Onset (<60yo & linked to genetics); Late Onset (>60yo & more common)

Dx Criteria: Dx of AD is made by clinical assessment. Memory impairment & ≥1 of; Aphasia, Apraxia, Agnosia, ↓ executive function. Ø Delirium or other CNS disturbance.

FEATURES

RONALD (Ronald Reagan, a famous victim):
R eduction of Ach
O ld age
N eurofibrillary tangles
A trophy of cerebral cortex (diffuse)
L anguage impairment
D ementia (MC in elderly)/ Down's syndrome

COMMON CHARACTERISTICS
ALZHEIMER'S:
A nterograde amnesia is usually first sign
L ife expectancy increase shows more cases in recent years
Z apped (loss of) acetylcholinergic neurons
H ereditary disease
E ntire hippocampus becomes affected
I dentified by neurofibrillary tangles
M utation in amyloid genes associated w/ disease
E ntorhinal areas degenerate first
R etrograde amnesia ultimaltely develops
S enile plaques are formed at synapse

RFs:

Advancing age
FHx
ApoE-ε4 genotype
Obesity
Insulin resistance
↑Lipids
HTN
Inflammatory markers
Down syndrome

Ix: MMSE, MRI, Screen for hypothyroidism & B12 deficiency

Tx: AChE inhibitors (donepezil, rivastigmine, galantamine). NMDA blocker (Memantine) to decrease glutamate excitation. Ginkgo biloba, Antioxidants (Vit E), Psychosocial interventions.

Happy New Year

2012-01-17T11:00:00.000+10:00

It is long overdue, but a Happy 2012 to everyone.

Stay tuned for some exciting posts coming to you in the next few weeks. In the meantime you can check out some of the biggest hits of 2011 on IVLine.

How to perform a Clinical Eye Exam

The eye allows us to observe the world around us, but it can also provide clinician's a window into a person's health. Often neglected and left to those dreaming of working as an Ophthalmologist, students and junior doctors alike miss out on a valuable source of information. Here the basics of the Clinical Eye Examination are introduced including reference to Dr John L Colvin and Dr Joseph A Reich's 35 Golden Rules of Eye Care.

Top 10 Medical Tweeters

A collection of some of the best medical tweeters out their in 2011. Most of them are still out there, typing away on their keyboards, tweeting with thumbs and spreading snippets of medical knowledge.

How to perform a Neurological Clinical Exam

Another important tool in a clinician's toolset. Neurological Clinical Exams are used in a variety of settings from the GP Clinic to in the Intensive Care Unit. This will take you through some basic anatomy, examination of the upper & lower limbs, and examination of the cranial nerves.

Basics of Acute Inflammation

One of the most relevant biological processes for medical students to understand. This takes a look at the basics of the process and even throws in a nice flow chart to help you out.

Creative Mental Health Posters

An effective mode of communicating information and engaging interest in a topic is via graphics. Here I showcase some thought provoking and well designed posters concerning mental health. Some highlight an aspect of a mental illness whilst other aim at raising awareness.

A Guide to taking a Psychiatric History

There are some areas like Psychiatry, where taking a good and thorough history can be more of a challenge for a medical student. The purpose of taking a Psychiatric History can split into three main things; diagnostic, to gain a biopsychosocial understanding of the patient’s problem, and therapeutic/psycho-educational.This guide sets out a basic structure by which these goals can be achieved.

Med in Small Doses - Huntington's Disease

2011-12-21T10:58:00.000+10:00

This is part of the Med in Small Doses series, which aims to give you a snapshot of a disease or disorder.

AD movement disorder due to CAG repeats in HD gene. 25-50yo. Commonly presents at age 40.
Dead within 15yrs. Prevalence 5/100 000.

HUNT 4 DATE: HUNTington's on chromosome 4, with cauDATE nucleus involvement.

PATHO: Autosomal dominant HD gene 4p16.3. Toxic gain-of-function on Huntington → protein aggregation → atrophy of caudate nucleus & putamen (striatum). Cortical atrophy, particularly frontal lobe. Ventricular dilatation.

CFs: Motor symptoms before cognitive impairment. Chorea, mental changes/dementia.

Ix: Genetic testing [sensitive (98.8%) & specific (100%)], Imaging Studies (e.g. MRI)

Tx: Symptomatic only: treat chorea (benzodiazepines), bradykinesia (L-dopa/DA Antagonists), delusions, depression (SSRIs). Physiotherapy.

Med in Small Doses - Parkinson's Disease

2011-12-15T13:30:00.000+10:00

This is part of the Med in Small Doses series, which aims to give you a snapshot of a disease or disorder.

Parkinsons: Dopamine stops working deep in brain, movement centres fail, shake at rest, slow down and ratchet. Time drugs perfectly. @Elytherius

PATHO: Progressive degeneration of DA neurons in S.nigra with loss of catecholaminergic neurons & gliosis. Synuclein and parkin genes involved. Lewy bodies (α-synclein aggregates).

CFs: Tremor, Rigidity Ankinesia/Bradykinesia, Postural instability, ANS dysfunction, Depression. DGEMMS of PD.

D ysphagia, drooling, ↓ voice

G ait: hesitation

E ye: no blink, flutter when closed

M icrographia

M ask-like faces

S ubcortical dementia

Dx Criteria: 2+ of Tremor, rigidity or badykinesia

RFs:

Male
FHx
Head injury
Rural
Pesticide exposure

Tx: Assess disability, medical therapy, respite care, surgery (DBS), exercise

Meds: Levodopa – replaces DA in S.nigra. can be combined with carbidopa.

DAR antagonists – monotherapy or with L-Dopa
Amantadine, COMT inhibitors
MAOi – inhibit breakdown of DA
Anticholinergics: Early PD