Hopefully we can now stop doing LP’s to rule out SAH if CT scan performed within 6 hours of onset

Written by admin on July 19th, 2011

The Canadian study by Perry et al just published in the BMJ studied 3132 patients with worst ever headache across 11 ED’s between 2000-2009 of which 240 (7.7%) had subarachnoid haemorrhage.

CT scanning overall had a sensitivity of 93% for detecting SAH, but if done within 6 hours of onset of headache and interpreted by an experienced radiologist, the sensitivity rose to 100% picking up ALL 121 patients with SAH of the 953 patients scanned within 6 hours.

Looks like its time to modify our practices as long as we have access to experienced radiologists – overnight may be an issue when such access may not be readily available.

Their related study (see pdf heretrying to develop a Canadian SAH rule of who to do a CT scan upon needs further validation but suggests that consideration for possible SAH and thus possible CT scan on all patients with sudden onset headache (reaching peak intensity within 1 hour of onset), which has not occurred more than twice over the past 6 months (thus excluding chronic recurrent headache patients), who have any of the following features:

  • age >= 40 years
  • witnessed LOC
  • complaint of neck pain or neck stiffness
  • onset with exertion
  • arrival by ambulance
  • vomiting
  • diastolic BP >= 100mmHg
  • systolic BP >= 160mmHg

Of the patients included in their study, 54% had benign headache, 27% migraine, 6.5% SAH, 4.3% viral, 1.8% TIA, and 1.5% had post-coital headache.

They used 3 rules using variable items above, and each of the rules had 100% sensitivity for SAH, while specificity ranged from 28-39%

It will be interesting to see how the validation studies pan out.

 

News from EMA Course in New York – IT systems in ED – need for scribes

Written by anitaliu on July 8th, 2011

I attended the EMA Course in New York last month and although IT systems were not directly part of the course, the topic did arise and the general feeling of the many US emergency physicians appeared to be that current commercial ED software in place in the USA is NOT efficient and comments such as “terrible” were not uncommonly expressed.

It seems that the consensus was that for EP’s to be productive with such software they each need to have a personal scribe to ensure adequate timely documentation while allowing them to have adequate time at the bedside with the patients.

Furthermore, it seems that the majority of prescibing mistakes are now because of software design issues and how the software interfaces with end users.

Perhaps Australian administrators should be taking heed – just because it “seems” to be a good idea and it is used in the USA does not mean it should necessarily be adopted here.

 

Victoria’s new Severe Substance Dependence Treatment Act 2010

Written by anitaliu on July 7th, 2011

This Act came into effect 1 March 2011 and essentially provides a mechanism for certain medical practitioners to detain and treat persons with potentially life threatening substance dependence and who are unable to consent to treatment.

See details on the wiki

 

Throwing a cat amongst the pigeons – cancer risk – will it change our referral pattern for cardiac diagnostic testing?

Written by Gary on February 16th, 2011

The recently published retrospective Canadian study of 5 year cancer risk following heart attack in 1996-2006 seems to demonstrate a consistent 3% increased risk in cancer per 10 milliSv radiation dose when adjusted for sex, age, comorbities (but strangely, not for smoking status, nor for actual measured radiation dosage but for presumed, estimated dosage based on investigations and procedures which were billed).

Nevertheless, the increased risk seems consistently increased as radiation dose increases and thus the results may be plausible.

Given the average age of these patients being ~61 years, some 14% were diagnosed with new cancers in the 2-5 years following their AMI, thus a relative increased risk of 3% per 10mSv is something to stress us!

See here for the paper.

This will inevitably put pressure on us NOT to refer patients for stress MIBI scans, nor diagnostic coronary artery CT scans.

In an ideal world, we would have timely access to a sensitive and specific radiation free investigation.

Unfortunately, stress ECG testing has a relatively low sensitivity and in younger women a higher false positive rate.

That leaves us with stress echocardiography, but availability and operator dependence means this also has issues at present.

Furthermore, the added morbidity associated with cancer risk may also impact who we should actually be referring for angiography and/or angioplasty.

Time will tell, but in the interim, perhaps the least we can do is provide adequate informed consent.

See wiki for more details of stress testing.

 

Apple iPhone apps for doctors and medical students

Written by Gary on December 14th, 2010

Just thought I would bring your attention to Houston Neal’s blog where he groups iPhone apps for doctors and medical students as I am sure many of the readers of this blog would be very interested.

Check out his blog here.

 

New drugs: Exenatide – an injectable diabetic agent and Denosumab – a monoclonal antibody for postmenopausal osteoporosis

Written by Gary on December 12th, 2010

Exanatide (Byetta):

  • the first injectable synthetic analogue of the incretin hormone glucagon-like peptide-1 (GLP-1)
  • note that the glyptins inhibit incretin breakdown and are thus incretin “enhancers” not “mimics”
  • PBS approved for type 2 diabetics as an addition to the combination of metformin and  sulphonylurea to help lower HbA1c below 7% or as dual Rx for those who cannot tolerate metformin or a sulphonylurea.
  • dose:
    • is given bd s/c within 1 hour BEFORE meals starting at 5 mcg per dose which should be at least 6 hours apart
    • after 1 month, dose can be increased to 10mcg bd
  • main adverse effects are:
    • nausea (50% initially)
    • vomiting
    • risk of hypoglycaemia (this risk is similar to use of insulin and mainly a risk with sulphonylurea combination)
    • pancreatitis – PH of pancreatitis is a C/I!
    • renal impairment
    • development of antibodies which in some may limit its effect (~3% of the 50% of patients who develop antibodies)
  • the actions include:
    • increase glucose-dependent insulin secretion
    • suppress inappropriate glucagon secretion
    • delay gastric emptying and thus delays glucose absorption
    • reduces appetite and may contribute to a 1-2kg weight loss

Denosumab (Prolia):

  • an alternative for Rx of postmenopausal osteoporosis
  • a human IgG2 monoclonal antibody that targets the RANKL (receptor activator of nuclear factor kappa B ligand).
  • this inhibition prevents the formation, function and survival of osteoclasts and thus decreases bone resorption and bone loss.
  • it could also be expected to impact upon bone remodelling and healing after fractures although evidence for clinical significance is not clear
  • it reduces the incidence of radiologically detected vertebral fractures from 7% with placebo to 2.3% but unfortunately, there are no comparison studies with other anti-resorptive therapies, but seems to increase bone density more than alendronate does.
  • it is given s/c injection every 6 months, but still requires supplemental calcium and vitamin D intake
  • adverse effects include:
    • hypocalcaemia
    • pancreatitis may be a risk
    • osteonecrosis of the jaw may also be a rare risk as with other Rx
 

New drugs on PBS: alfuzosin, clofarabine, melatonin, nebivolol, rizatriptan and ustekinumab

Written by Gary on April 16th, 2010

New drugs on Australia’s PBS schedule:

Alfuzosin:

  • Xatral SR 10mg prolonged release tablets
  • alpha-1 adrenergic blocking agent for use in Rx of benign prostatic hypertrophy, similar to prazosin, tamulosin and terazosin
  • vasodilator so may cause postural hypotension
  • only modest benefit over placebo and no difference in efficacy between the alpha-1 adrenergic blocking agents.

Clofarabine:

  • Evoltra
  • a purine nucleoside analague used in Rx of paediatric acute lymphocytic leukaemia

Melatonin:

  • Circadin 2mg prolonged release tablets
  • a natural hormone available for Rx of primary insomnia in those aged over 55 years
  • only marginal benefits over placebo for most patients with only 30% responding

Nebivolol:

  • Nebilet 1.25mg, 5mg and 10mg tablets
  • beta1 blocker with mild vasodilatory properties via nitric oxide release
  • used in Rx of hypertension (1.25mg up to max. 40mg once daily) and stable chronic heart failure (1.25mg, gradually increase to 10mg once daily if tolerated)
  • benefits over other beta blockers are not yet clear clinically

Rizatriptan:

  • Maxalt 10mg wafers
  • Rx of acute migraine
  • mainly acts as agonist on 1B and 1D serotonergic receptors
  • more patients respond to 10mg rizatriptan than to 100mg sumatriptan, but headache was more likely to return and necessitate a 2nd dose after 2 hours
  • overall efficacy is similar to sumatriptan

Ustekinumab:

  • Stelara 45mg for injection
  • a humanised monoclonal antibody which suppresses the immune system by blocking the inflammatory actions of IL-12 and IL-23, and is thus used in Rx of unresponsive psoriasis.
  • a s/c dose is given at 0,4 and then every 12 weeks
  • serious side affects include angina, stroke, hypertension, intervertebral disc prolapse, dactylitis, clavicular fracture, sciatica and nephrolithiasis, while one 33 yr old man died suddenly while taking a 90mg dose and the death was thought to be related to a dilated cardiomyopathy
 

Want a new easy way to write a medical knowledge article and have full control over it rather than use a wiki or personal website? Try a Google Knol.

Written by Gary on January 26th, 2010

Google has created a new knowledge-based system which allows experts (such as us), to write knowledge-oriented articles complete with images, multimedia and links which only the author can update.

This may suit doctors who wish to help share knowledge but wish to still retain control and have all their articles linked in the one place.

For instance, this US dermatologist has written articles on:

A wiki such as the Ozemedicine wiki is great for collaboration and keeping everything linked together and searchable without ending up getting lots of extraneous search results from the millions of non-authoritative authors which have taken over the internet world.

Wikipedia itself is useful, but there is no easy way of protecting your efforts from being edited by non-authoritative authors – hence the reason for the creation of the Ozemedicine wiki – only authorised persons can edit these wiki pages.

But for many, a wiki does not give them the control and recognition they would like, while the effort of creating a personal website is not the way they would like to spend their spare time.

Furthermore, a blog system such as this is not a great way of archiving and updating knowledge-based articles given that articles posted on a blog are ordered according to date initially posted and linking to older posts  is a bit of a chore.

A Google Knol may be the answer if you find yourself in this category – easy to create, edit and publish, even host your images, etc.

However, be aware, your articles will be listed amongst the thousands of bogus Knol articles promoting health products – if you want isolation from such marketing forces, then becoming an author on the Ozemedicine wiki may be a better option – there are no ads!

If you do create a nice article, please let me know so I can link to it from within the wiki – as the Ozemedicine wiki is still potentially the most powerful and efficient portal to timely useful ED-oriented material for Australians.

For instance, I have added links to the above Knols to the wiki dermatology index page and thus these will appear in a wiki search.

 

New Victorian notifiable conditions

Written by Gary on January 7th, 2010

Victoria’s Dept of Health have updated their notifiable conditions:

  • Giardia has been removed
  • Chikungunya virus infection (mosquito spread infection in Africa, Asia and the nearby islands including Papua New Guinea) has been added
  • Blood lead levels greater than 10 microgram/dL has been added
  • Hepatitis A is now  Group A condition-  no longer in Group B

Secure online notifications and downloadable forms can be accessed via this website.

 

New PBS drugs: Prasugrel, Pramipexole and Olanzapine depot injection

Written by Gary on December 23rd, 2009

NPS RADAR for December 2009 reports 3 new PBS listings:

Prasugrel (Effient):

  • new antiplatelet drug from same class as clopidogrel with even less risk of non-fatal myocardial infarction but greater risk of bleeding.
  • TRITON-TIMI 38 trial which excluded high risk of bleed patients showed that for every 1000 patients, 22 fewer would have composite of death from CVS causes, non-fatal AMI or non-fatal stroke, but 6 more would have major bleeding. Patients who underwent CABG had 102 more major bleed events per 1000 patients.
  • irreversibly blocks P2Y12 adenosine diphosphate receptors.
  • authority required for use in Mx of ACS via percutaneous coronary intervention in combination with aspirin.
  • recommended dosing: 60mg load (6x10mg tabs) then 10mg daily.

Pramipexole (Sifrol):

  • a non-ergot dopamine agonist used for Rx of Parkinson’s disease and Restless Legs Syndrome
  • it’s use instead of levodopa as initial Rx for early disease, delays the development of motor complications but increases somnolence and oedema.

Olanzapine Depot Injection (Zyprexa Relprevv):

  • allows deep im injection every 2 or 4 weeks, but risk of post-injection syndrome of sedation +/- delirium for up to 3 hours with every dose.
  • recommended starting dose is 210-300mg every 2 weeks depending upon current daily oral dose.