Greater Sydney Area HEMS

http://www.bbc.co.uk/programmes/p016qnkt

Click the above link to see the BBC’s take on the exploits of our very own HEMS doctors and paramedics as they head out on mission.

The series was filmed with ourselves over the past few months with the cameraman

joining the crew whenever it was operationally appropriate (and a British accent likely to be heard in the cabin).

We think they’ve given a good feel for the vast cross section of patient groups, distant geography and difficult environments our service is asked to deal with every day.

NB – please note that John Glasheen (pictured above) whilst featuring in the BBC’s gallery of British docs abroad, in fact hails from Tipperary in the Republic of Ireland. We don’t believe this was due to any misdirection on their behalf but simply a result of not being able to understand his accent.

Well it’s all done and dusted and the academic hangover is a heavy one. However, with the highly digitised platform of proceedings it’s no surprise that for most the dream lives on in the twittersphere and various FOAMed connections that have been forged or strengthened as a result of the highly successful SMACC conference held in Sydney’s Darling Harbour, now concluded. Here are some of the Sydney HEMS docs thoughts on how the meeting of critical care avatars from around the world went:

“Engaging and dynamic speakers.”

“John Myburgh’s talk on inotropes was a vindication for my practice of picking either adrenaline or noradrenaline and using enough of it.”

“Critical care controversies discussed with an interactive platform.”

“Inspiring teaching on human factors, teaching and learning – how to be a better resuscitationist and lifelong learner.”

“A few speakers mentioned the practice of using inotropes in the setting of acute spinal cord injuries to keep the MAP above 80mmHg for up to one week post injury. I’m not sure the evidence is great for this, but it has prompted me to dig further.”

 “SMACC was unquestionably the best critical care conference ever. Amazing speakers and great buzz.”

 “I was interested to hear about the increasing early use of inotropes in sepsis, after two or three litres of fluid rather than six. This will change my practice.”

 “Great contribution from the service with 4 speakers including Cliff giving 2 inspiring talks.”

 “My 3 favourites were John Myburgh’s talk on inotropes, Chris Nickson with All Doctors are Jackasses on meta-cognition and Mr Emcrit with a talk on the Road to Mastery.”

“The conference with the most hugs I’ve ever experienced.”

How can this many happy physicians be wrong?? (NB – please note all negative commentary excluded as per standard blog policy)

Here at Sydney HEMS we are very excited to be geographically close to (and thoroughly supportive of) the Social Media And Critical Care conference which begins tomorrow at Darling Harbour Convention Centre.

It brings together all the critical care specialties to discuss both cutting edge clinical care and innovation in education and will harness all the digital and online platforms which 21^st century folks require to make this a face to face conference even if you’re unlucky enough not to actually be there.

For those as interested as us

Program details are at

http://smacc.net.au/program/

There is already a wealth of educational goodness on the SMACC YouTube Channel at http://www.youtube.com/user/TheSMACCchannel

You will be able to follow and interact with the sessions via Twitter – if you’re new to Twitter watch this:http://intensivecarenetwork.com/index.php/component/content/article/950-conferences-a-courses/477-twitter-for-smacc

Details on how to follow the various open access online components are at:

http://www.intensivecarenetwork.com/index.php/component/content/article/950-conferences-a-courses/479-live-smacc-down

This 22 minute talk by Dr Karel Habig is aimed at new members of the Greater Sydney Area HEMS team. It covers the standardised approach we use for prehospital RSI to minimise the risks of hypoxia and hypotension. Many of the aspects of this system are also applicable to hospital-based practice.



The RSI Manual is here

The RSI Operating Procedure is here

With the arrival of the flash new Oxylog 3000+ there’s been quite a bit of discussion around the base recently about modes ventilation.  There still seems to be quite a bit of confusion about Autoflow.  In my humble opinion, mechanical ventilation is rarely particularly well taught.  For most doctors, the only formal training on modes of ventilation is a hastily delivered tutorial from the flustered registrar during their first week as an ICU resident, perhaps with some random graphs scribbled on a napkin.  Hardly quality clinical education.  As a result ventilators continue to be scary machines for many docs.  There have been plenty of opportunities in the past to own the oxylog, and I don’t want to reinvent the wheel.  I think it’s worth reviewing autoflow though.

Autoflow is Drager’s method of delivering a mode of ventilation otherwise known as volume assured pressure control, or pressure regulated volume control (PRVC – Maquet’s version).  Essentially its a type of ventilation that seems like volume control, in that you dial up a tidal volume, but delivers a decelerating ramp pattern inspiratory flow, so behaves like pressure control.  So you get the simplicity of volume control with the benefits of pressure control.

So how does it work?  Well let’s say you have a 70kg patient and you want to deliver 6mL/kg (as you always should…) so you dial up a Vt of 420mL.  The ventilator will deliver a standard volume control breath of 420mL using the minimum possible flow (for a RR of 20 and an I:E ratio of 1:2 that would be 1 second Insp time and therefore a flow of 25L/min) and measure the end insp pressure.  This pressure will then be used to deliver a pressure control breath as the next breath.  The Vt delivered by the pressure control breath will then be compared to the set Vt, and the insp pressure adjusted up or down by 3cmH2O pre breath until the desired Vt is consistently delivered.  This means that if there are dynamic changes in pulmonary compliance, the insp pressure will also change in order to deliver a constant Vt at the lowest possible Insp pressure.

Maquet’s PRVC is very similar, except that the first breath is PC, at an arbitrary Pressure, which is then adjusted over subsequent breaths to meet the set Vt.  This diagram from the Chinese University of Hong Kong’s excellent Basic Assessment and Support in Intensive Care (BASIC) course sums it up pretty well

One thing to note is the Autoflow/PRVC isn’t a mode of ventilation as such.  It’s just a way of delivering the breath.  You still select SIMV, CMV etc as the mode of ventilation.  Remember that in general you should only use CMV in curarised or very heavily sedated patients.

So why bother?  Well, pressure control ventilation limits peak airway pressure and thus avoids barotrauma which may help prevent ARDS.  It’s also beneficial in traumatic brain injury, as high airway pressures may be transmitted to the brain via increased venous pressure.  It may also improve oxygenation in patients with poor compliance or with lung units of differing compliance. Pressure control may also be more comfortable for less heavily sedated patients.

Sounds good, what’s the catch?  Well, while avoiding the main disadvantage of PCV – the inability to deliver a constant minute volume in the face of dynamic changes in pulmonary compliance – Autoflow will limit the volume delivered once the preset pressure limit is reached.  In fact it will cease inspiratory flow 5cmH20 before the pressure limit is reached.  The alarm “Vt low, pressure limit” will appear on the screen and the high priority alarm will sound.

I think Autoflow and it’s cousins are a good thing and together with low tidal volumes will be good for our patients, but like all new toys, we just have to have a play with them and get used to them.  Don’t just take it from me though, here are some great resources that explain Autoflow and mechanical ventilation in general.

Drager Autoflow tutorial booklet

BASIC course PRVC tutorial

Our HEMS colleagues across the ditch in Auckland, NZ have started a website that looks like it will be a great source of information on prehospital care ad medical education.  The Auckland Rescue Helicopter Trust (AHRT) is the latest addition to the Australasian HEMS family, with a 2 year feasibility study of adding full HEMS capability with medical crewing using a joint physician/intensive care paramedic (ICP) to their existing ICP only platform.  It will be interesting to see what they show, as ICPs in NZ are already very highly trained with quite liberal protocols including ketamine and RSI without direct medical oversight.

Of note, AHRT were the first civilian surf rescue helicopter service in the world and carried out the first recorded surf rescue by helicopter in 1970 using a Hiller 12E. They’ve moved on a bit and currently operate 2 BK-117s but rumour has it they’re soon to move to the shiny new AW-169.  Who knows, maybe we’ll see them at smacc…?  Check out their site at http://aucklandhems.com