This years World Extreme Medicine conference was held at Dynamic Earth in Edinburgh. It was an inspiring and interesting weekend filled with talks from a wide range of incredible speakers from astronauts to Arctic explorers. Here are my top three talks. If these sound interesting you can find recordings of many of the talks at the World Extreme Medicine Facebook page – click on the videos tab in the sidebar.
1. Chris Imray presents New Research into the Effects of Altitude on Brain Activity
At 9am on the first day Professor Chris Imray set the pace for the weekend, by delivering a fascinating talk on ‘Extreme Altitude Cerebral Dysfunction’.
He suggested that this is a distinct pathology that should be added to the list of high altitude cerebral pathologies - High Altitude Headache (HAH), Acute Mountain Sickness (AMS) and High Altitude Cerebral Edema (HACE).
Extreme Altitude Cerebral Dysfunction comprises of a rapid staged degradation in cerebral function as oxygen delivery falls below the level that is required.
To describe it biochemically, there is an imbalance between cerebral oxygen delivery and cerebral oxygen demand. The subsequent lack of oxygen to the brain leads to falling ATP, rising ADP and neuronal dysfunction.
People suffering from Extreme Altitude Cerebral Dysfunction rapidly decline from: “Chatty, initiating new lines of conversation” -> “Sense of humour failure” -> “Rigid conversation” -> “Monosyllabic answers” -> “Loss of motor power” -> “Unconscious”.
Although a separate entity from HACE, the two can co-exist and there may be an overlap. Extreme Altitude Cerebral Dysfunction can be very rapid in onset and is not associated with cerebral oedema. It is reversed rapidly with oxygen and dexamethasone is unlikely to help.
Extreme Altitude Cerebral Dysfunction
Can be rapid onset
Development of cerebral oedema
ICP probably unchanged
Not reversed immediately with oxygen
Reversed with oxygen
Dexamethasone unlikely to help
The differences between HACE and Extreme Altitude Cerebral Dysfunction
Many at the conference identified with this new pathology – describing situations where a case of presumed HACE has resolved almost immediately with oxygen alone - thus making true cerebral oedema very unlikely.
Have you treated any cases of presumed HACE that may actually have been Extreme Altitude Cerebral Dysfunction?
2. Mike Christian and Matthew Walton present HEMS Team Insights: Resilience – Coping after Critical Incidents
Dr Matthew Walton was a final year medical student when he shadowed the Essex and Herts Air Ambulance HEMS team. During this time he attended a call out to a traumatic paediatric cardiac arrest which left him with flashbacks of the event for several months afterwards.
Fortunately for Matthew, Dr Mike Christian, the senior HEMS physician, had debriefed him after the event and explained the feelings that he might experience after such a traumatic experience. He and Mike stayed in touch and went on to make a brilliant short film as a teaching resource for similar teams. The aim of the film is to normalise people’s reaction to traumatic critical incidents, and encourage an open dialogue after such events. (Watch it here: https://youtu.be/DY60ZOWBvDc)
Matthew, a keen amateur filmmaker, has since gone on to make a second film, focusing on the emotional resilience of volunteer responders in the Melrose Mountain Rescue Team after they attended a call out to an avalanche victim. (Watch it here: http://youtu.be/qabCvFwmNyo)
The key message is that emotional resilience is fostered not from within one individual, but between individuals in a team - through open conversation about traumatic incidents and the emotional responses experienced by the team.
The films have been a huge hit and now feature on NHS Scotland Resilience resources webpage (http://www.sad.scot.nhs.uk/resilience/
http://lifelinesscotland.org), BBC breakfast, MIND website and has even been endorsed by Stephen Fry!
3. Gaynor Prince presents USS in Extreme/Austere Environments
Dr Gaynor Prince is an Emergency Physician in Western Australia and self declared "ultrasound nerd"! She holds a Diploma in Diagnostic Ultrasound and has taken her portable ultrasound probe with her to many extreme environments. In this talk, she describes the ways in which she used ultrasound during her two-month assignment as the medic at Union Glacier camp, Antarctica*.
Gaynor used her ultrasound probe to settle a diagnostic dilemma when a male client on a Last Degree expedition presented with shortness of breath at the South Pole. His obs and history led her to a working diagnosis of pneumonia, however the differential diagnosis was HAPE and PE (recent long flight into the Antarctic). She was able to use ultrasound to see there was no edema in the lungs and thus ruled out HAPE. In addition, she was also able to confirm the absence of right heart strain and therefore exclude a PE. She was therefore able to keep the client at the South Pole until his planned departure date.
Gaynor also gave an example of ultrasound use in confirming the diagnosis of a fractured neck of femur in a fallen skier, and its role in allowing her to give a femoral nerve block in order to allow adequate analgesia for a bumpy medevac back to Chile.
Whilst many of you may be picturing bulky ultrasound devices, in fact Gaynor uses a Philips Lumify, which consists of just three small probes that plug into any android tablet. Unfortunately, this convenience comes at a price, about £7,000 today, but the future of portable ultrasound is bright! New technology - using electronic chips in place of piezo crystals - is about to be released in the USA. A device like the Butterfly iQ will cost around £1,500 and the makers intend to bring the cost down even further with time.
Gaynor predicts that, in the future, ultrasound probes may be part of a doctor's everyday kit. The USA has already introduced ultrasonography into medical school curriculums and Australia is to follow suit soon. For the doubters among you, I leave you with this quote from Dr John Forbes.
“That it will ever come into general practice, I am extremely doubtful. It's beneficial application requires much time and gives a good bit of trouble, both to the patient and the practitioner.”
Dr John Forbes on the stethoscope, 1823.
*For further information on the use of ultrasound at high altitude its worth taking a look at:
Dr Sophie Mohun Kemp is a Core Medical Trainee working at Kings College Hospital and spends as much time as possible getting out of London to climb, scramble and hill-walk. She loves the snow, especially touring on her splitboard. Sophie is planning to move to North Wales next year and hoping to gain a place on the DiMM with the aim of carving out a a career that links medicine and the mountains!