Neuro Resus

WIN October Dinner 2016: Death and Dying in the Intensive Care Unit

learnECMO

Roger Pye on cannulation, part 1.

This podcast is the first of 2 parts of the Cannulation 101 session from the recent ECMOcannulate course. It is delivered by a true expert in the form of Roger Pye, erstwhile renal physician, intensivist and cardiac anaesthetist with 10 years of ECMO retrieval experience.

In part 1 Roger gets right down to the grain on VV cannulation and just how vital cannula configuration is to optimising systemic oxygenation, an essential consideration when bundling ECMO patients up for a 4000km aeromedical retrieval.

Look out for part 2 which will cover the Avalon cannula and cannulation for VA ECMO.

Thanks for listening. If you're interested in honing your cannulation skills go to learnECMO.com to register your interest for ECMOcannulate in 2017. We will also be in Berlin at the blue riband crit care conference, das SMACC, where we will invite all comers to set the ECMO cannulation world record.

Summary by Lachlan Donaldson

The debate regarding the efficacy of thrombolysis grumbles on… How is it that two different groups (i.e. mostly ED doctors and neurologists) can look at the same set of trials and come to fundamentally different conclusions?

To examine this, these authors have attempted to perform an unbiased meta-analysis and systematic appraisal of the evidence supporting the use of thrombolysis in ischaemic stroke (paper available here).

Consistent with other meta-analyses, the authors found a moderately increased probability of good functional outcome (OR 1.14) alongside a markedly increased risk of ICH (OR 4.28).

However, as discussed, this debate is likely to be driven by the quality of the trials that populate this meta-analysis.

For instance, of the 16 studies that nominated a specific primary outcome, only 2 studies reported a significant treatment effect in favour of thrombolysis as their primary outcome- the NINDS trial and ECASS III. Both of these studies have reported concerns baseline imbalance.

Buried in the Supplementary Appendix is also the 'influence analysis' which shows the significant influence of the NINDS and IST-3 trial, both of which have significant methodological limitations.

Transparently analysing this controversial data was not without challenge – most trialists and drug companies were reluctant to share trial data without contracts and editorial influence (notwithstanding stated commitments to data-sharing). Once completed, most journals with broad readership rejected the paper on the basis that there was no ongoing debate; their view was that that the evidence was sound and that replication studies were not warranted.

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Associate Professor Vincent Pellegrino is a Senior Intensive Care Specialist at The Alfred Hospital and head of the ECMO Clinical Service. He has had a lead role in the development of ECMO services at The Alfred since 2003. From the ECMO CPR ICN Victoria meeting he discusses how to get patient selection and outcomes right for eCPR.

Peter McCanny is part of the LearnECMO team. In this podcast he explains some of the background and history of ECMO CPR, what evidence there is to support its use and where we're heading in the future.

Basic Science Clinic by Steve Morgan & Sophie Connolly

In the words of the 3rd greatest physicist of all time, James Clerk Maxwell:

"It is of great advantage to the student of any subject to read the original memoirs on that subject, for science is always most completely assimilated when it is in the nascent state."

Welcome to Basic Science Clinic Raw Science 10. Not before time we are ready to approach the alveolar-capillary membrane to substantiate the factors that determine the reciprocal exchange of biologically operative respiratory gases. For all the demonstrable complexity of transport and signaling mechanisms in the human body, the energetically neutral transaction of simple passive diffusion is culpable for the cascading maintenance of gas exchange homeostasis and oxidative phosphorylation, with its explosive potential for driving the evolution of ostentatious biological complexity. The adaptive imperative to exploit diffusion for gas exchange imposes certain anatomical demands on the respiratory system. Namely the requirement for a huge tissue surface area of negligible thickness, and minimising diffusion impedance, whilst ensuring dependable partitioning of air space and blood compartments, even in conditions of extreme flow and pressure fluctuations. In this pod we will detail the determinants of diffusion and unravel its antecedence to the segregation of the pulmonary and systemic circulations as a prelude to dissecting the emblematic features of pulmonary perfusion.

In this podcast:

What is Graham's Law?

How does diffusion proceed in the human lung?

So where does Fick's law fit in?

What is meant by diffusion and perfusion limitation?

How do we quantify pulmonary diffusion?

What are the physiological components of the diffusing capacity?

How is diffusion responsible for the pulmonary circulation?

Here are some Raw Science factoids:

As barometric pressure reduces linearly with altitude, it reaches 30% of that at sea level when entering the death zone at 8000m, which coincident with an inspired oxygen partial pressure of only 48 mmHg and life-threatening diffusion limitation.

Breathing carbon monoxide at a fractional concentration of 0.0128, 1.28% or 12800ppm leads to unconsciousness in 2-3 breaths and death in under 3 minutes.

Selective breeding of elite racehorses means they can generate pulmonary capillary pressures of the order of 100 mmHg during galloping, leading to near ubiquitous stress failure and varying degrees of exercise-induced pulmonary haemorrhage.

For feedback, corrections and suggestions find us on the twitter handles @falconzao and @sophmconnolly or alternatively post on ICN. Also check out our website basicscienceclinic.com.

Thanks for listening. Next up we'll perform a detailed public vivisection of the pulmonary circulation.

ECMO Gas Exchange by Steve Morgan & Sophie Connolly

This is the first in a series of ECMO podcast from the LearnECMO team - starting with the physiology of ECMO gas exchange.

Professor Stephen Bernard is an Intensive Care Physician at The Alfred Hospital and Medical Advisor to Ambulance Victoria. His research interests include the use of therapeutic hypothermia for the treatment of neurological injury after resuscitation from out-of hospital cardiac arrest. Here he provides a presentation on recent advances in the management of refractory cardiac arrest in the out of hospital setting.

Jason Maclure is deputy director of Intensive Care at the Alfred Melbourne. He has strong interests in analgesia and sedation, respiratory failure, ventilation, HFOV and ECMO. From an ICN Victoria 2016 meeting on ECMO CPR he discusses the development of the eCPR protocol at the Alfred.

Huy Tran is a lab and clinical haematologist at Peninsula Health. He has research interests in haemostasis and thrombosis and is a member of the Australasian committee for anticoagulation reversal. This is his presentation from an ICN Victoria meeting where he discusses the new oral anticoagulants and what can be done when they cause critical bleeding