The Pre-hospital Care Conference was the third and final day of the London Trauma
Conference. The first speaker, Professor Malcolm Woollard, Director, Pre-hospital,
Emergency & Cardiovascular Care Applied Research Unit, Coventry University, spoke
on Needle Decompression of the Chest – fact or fiction? Professor Woollard’s comprehensive
review of the epidemiology, appropriateness, effectiveness and risks of the procedure
illustrated some interesting and important points. He argued that needle decompression
of the chest is an infrequently performed procedure with currently taught techniques
risking inappropriate use, failure and iatrogenic injury. Critically, multiple studies
demonstrate that a standard 14G cannula of 4.5cm length will not penetrate the chest
wall in many patients. Moreover, retrospective analysis of interventions undertaken
reveals that the insertion site is often incorrect and frequently in the cardiac zone.
He concluded that the intervention does have a role in the emergent management of
trauma patients but emphasised that appropriate equipment should be used by practitioners
with regular re-training in indications, technique and positioning.
Surgeon Commander Jason Smith, Royal Navy Consultant in Emergency Medicine, Derriford
Hospital recently led a UK consensus group on treatment of crush injury and he spoke
on Crush Injury – is it More Than One Syndrome? He answered this question by broadening
the definition of the syndrome to ‘the systemic manifestation of muscle cell damage
resulting from pressure or crush’ rather than the conventional perception of an injury
caused by prolonged entrapment. He encouraged delegates to consider the diagnosis
in a broad range of presentations and explained that the severity of the syndrome
depends upon the magnitude and duration of the force and the bulk of muscle affected.
This focus on damage to the sarcolemma explains how the same condition may develop
from an instantaneous massive energy transfer or the prolonged application of a minor
force to a large muscle bulk, such as that seen during prolonged immobility on a hard
surface. The management of this condition adds an extra dimension to conventional
trauma management and hyperkalaemia should be considered as a reversible cause of
traumatic cardiac arrest when crush injury is suspected. Prevention of renal failure
is paramount in the medical management of crush injury and, again counter to the current
management of trauma patients, Surgeon Commander Smith advocated that aggressive crystalloid
resuscitation be commenced in the pre-hospital setting. Reports from the management
of crush injury in earthquake victims associate delay to fluid resuscitation as a
risk factor for the development of renal failure. Mannitol and urine alkalisation
should be considered although the evidence is limited, dated and largely anecdotal.
Surgeon Commander Smith’s enthusiastic talk was interspersed with reverential pauses
to admire spectacular photos of Royal Navy ships and helicopters – his prehospital
workplace is rather more impressive than that of most of the conference delegates.
The controversial topic of Compression only CPR was addressed by Professor Kjetil
Sunde, Oslo University Hospital, Norway in a fascinating and thoughtful analysis of
some conflicting literature. There was a conventional central theme to this wide-ranging
lecture: survival of cardiac arrest depends upon the chain of survival, consisting
of early recognition, early CPR, early defibrillation and post resuscitation care.
Professor Sunde’s unapologetic recycling of this familiar message was reinforced by
the evidence that there is a 10 fold variation in reported OOHCA outcomes and that
much can be done to improve the vital chain of survival. Evidence was presented to
confirm that both early initiation and quality of CPR are critical and that the evidence
demonstrating the superiority of compression only CPR over conventional 30:2 may reflect
this. Non-CPR trained bystanders, particularly when guided by telephone instructions,
are more likely to commence resuscitation and achieve adequate cardiac output with
compression only CPR than when interrupted with reluctant attempts at ineffective
ventilation. Despite this data, animal and human studies demonstrate that survival
and neurological outcome are improved by effective ventilation and cerebral oxygenation.
As a conclusion to the title of his talk, Professor Sunde advocated that CPR-trained
bystanders and medical responders should continue conventional 30:2 CPR to optimise
outcome. However his principle message was that the local variation in the outcome
of OOHCA is unacceptable and that multiple studies demonstrate a simple and achievable
solution to the problem: education of the general public in Basic Life Support. His
thought provoking final comments were that randomised controlled trials on the minutiae
of in-hospital care are irrelevant when compared to the potential for 10-fold increases
in survival with education programmes.
The conference paused for coffee before a heretical session on pre-hospital interventions
that challenged current recommendations by several international bodies. Professor
David Lockey returned to the stage to convincingly advocate the Emergency Surgical
Airway over needle cricothyroidotomy. Published cricothyroidotomy rates in emergency
intubation vary from 0.3-1.0% [1,2], but current UK Difficult Airway Society guidelines
are mildly ambiguous in the choice between needle and surgical technique in the ‘Can’t
Intubate, Can’t Ventilate’ scenario, suggesting the use of a needle cricothyroidotomy
before resorting to a surgical airway [3]. Professor Lockey argued that, when the
airway is lost in the emergency prehospital situation, indecision and delay would
increase the risk of hypoxic injury. He described a simple surgical technique with
basic equipment that has been demonstrated to have a success rate of 100% when performed
by prehospital physicians. His message was reinforced by evidence that needle cricothyroidotomy
in the emergency scenario has a high failure rate and high rate of conversion to surgical
cricothyroidotomy. A thorough review of the evidence was supported by the inclusion
of the recent National Audit Project 4 from the Royal College of Anaesthetists, and
the current European Resuscitation Council guidelines, both of which now advocate
the use of surgical cricothyroidotomy over needle or cannula cricothyroidotomy [4].
Dr Dan Ellis, Consultant in Emergency, Critical Care and Pre-Hospital & Retrieval
Medicine, Royal Adelaide Hospital, Australia talked passionately about pre-hospital
resuscitative thoracotomy and immediately made a clear distinction between this procedure
and in-hospital surgical thoracotomy. Pre-hospital resuscitative thoracotomy is performed
only when a trauma patient is in cardiac arrest or an agonal state. Although historically
manyl international authorities viewed the resuscitation of such patients as futile,
London Air Ambulance’s data on pre-hospital resuscitative thoracotomy tells a very
different story. Published international survival rates from traumatic cardiac arrest
of all causes vary from less than 3 to 7.5%, [5], however pre-hospital resuscitative
thoracotomy when performed according to local protocols in the context of penetrating
injury has a survival rate of 18%. Australian, Japanese and US data of resuscitative
thoracotomy in the ED also refute accusations of futility. Dr Ellis concluded that
the evidence strongly supports the use of pre-hospital resuscitative thoracotomy in
penetrating trauma with a likely duration of cardiac arrest of less than 15 minutes
and advocated the clamshell technique. To add fuel to the fire of controversy he suggested
extending the indication for the procedure to witnessed cardiac arrests from blunt
trauma to achieve aortic control.
The Keynote Address of the pre-hospital care conference was given by Dr Arnd Timmerman,
who has recently published the German society of anesthesiology and intensive care
medicine airway management algorithm. Dr Timmerman spoke on the subject of pre-hospital
airway management and his analysis of the evidence revealed that superficially reassuring
intubation success rates hide a mass of morbidity and mortality behind reporting bias,
selection bias, missing data and inadequate data collection. He suggested that the
pre-hospital environment increases the difficulty of intubation and equipment limitation,
particularly end tidal CO2 monitoring, result in significant rates of unrecognised
oesophageal intubation with a high consequent mortality. After analysing the use of
extraglottic (supraglottic) airway devices Dr Timmerman presented his recently published
algorithm for pre-hospital airway management. He emphasised several key points: the
need for strict indications for invasive airway management, mandatory use of end tidal
CO2, education of pre-hospital clinicians and the consideration of extraglottic airways
as a primary approach when difficult intubation is anticipated. This talk concluded
a very challenging and stimulating morning and the delegates enjoyed lunch in the
London summer sun.
The first afternoon session addressed large scale incidents and the delegates heard
two fascinating and very different talks. Dr Malcolm Russell, Clinical Lead of Surrey
and Sussex Air Ambulance and a member of the UK Search and Rescue team gave an inspiring
lecture on Medical Support for Natural Disasters – experience from New Zealand and
Japan. The logistics behind deploying a self-sufficient 65 man search and rescue team
at short notice to anywhere in the world on a minuscule budget was fascinating. His
description and photos of both events was humbling and distressing. Following the
earthquake in Christchurch, New Zealand, the team was assigned to a collapsed office
block where they worked day and night for over seven days to assess for signs of entrapped
survivors. Sadly no one was recovered alive from the building, but the team made an
important contribution by extricating 13 bodies and returning them to their families
for burial. The disaster caused by the Japanese tsunami was on an entirely different
scale and Dr Russell’s post-apocalyptic photos of obliterated towns were horrifying.
It was startling how little medical care was required on both missions but that at
these particular disasters the doctor’s role was one of maintaining the health of
the team and adding an extra pair of hands to the rescue efforts.
Professor Pierre Carli started his talk entitled Dealing with urban terrorism: the
French approach with an irreverent joke at his hosts’ expense; with Gallic confidence
he proposed that the French were better than the British at cooking, perfume and seduction,
and that he would demonstrate that they were also better at planning for the medical
response to terrorism. At the end of his direct and practical lecture, the British
in the audience were tempted to agree. Professor Carli explained that physicians lead
routine French pre-hospital care both on scene and at the control centre, where a
physician with several operators will coordinate medical resources. This physician-led
command and control structure combined with domestic experience of bombings, shooting
and toxic chemical release in France has resulted in clear and well rehearsed mass
casualty plans. Pre-hospital doctors will run an advanced medical post on scene, including
facilities for decontamination and advanced medical care, liaise closely with the
in-hospital response and may trigger pre-agreed plans to triage stable patients to
distant hospitals to allow efficient casualty flow. This system aims to avoid the
uncontrolled overwhelming of local hospitals and the need for resource-intensive secondary
transfer seen in incidents in Israel and USA where pre-hospital command and control
is limited. This impressive coordination of major incident response is lead by regional
‘Prefects’, with considerable powers, who can monitor the flow of electronically tagged
patients and available resources on a central computer.
After a short break, the final session of the conference reflected a couple of current
social and medical vogues: the obesity epidemic and therapeutic hypothermia. Dr Miles
Dalby, Consultant Cardiologist, Royal Brompton and Harefield Hospitals, London enthused
about Cath labs and cardiac arrests with infectious passion for providing prompt primary
angioplasty. Even the commonly encountered barriers to its provision such as normal
post-arrest ECG or ongoing CPR were discounted. Realtime video of door to coronary
stenting times demonstrated that the low technology solutions of multidisciplinary
team-work and proactive leadership can deliver fantastic results. Dr Dalby also presented
fascinating data demonstrating that mild therapeutic hypothermia induced around the
time of primary angioplasty may reduce myocardial infarct size and improve contractility,
providing yet another clinical application for this simplest of interventions.
Dr Matt Thomas, Consultant in Intensive Care at the University Hospitals, Bristol
gave a very entertaining and practical lecture entitled Big Problems in Pre-hospital
Care. The serious subtext to his talk was that the burgeoning population of obese
patients present challenges at every stage of their pre-hospital and in-hospital care
that require specific provision in terms of equipment and training. Practical tips
for the safe management of the bariatric patient included the ramped position for
intubation, early resort to supraglottic airway devices, the use of blood pressure
cuffs on the forearm, and the tolerance of high airway pressures during ventilation.
Dr Thomas presented surprising data to demonstrate that contrary to the expectation
of many clinicians, obese patients have higher than the survival rates of non-obese
patients with ischaemic heart disease, renal failure and on critical care. He argued
that this ‘obesity paradox’ should dispel the medical prejudice that obese patients
sometimes encounter.
A fascinating day concluded with a second talk from Professor Kjetil Sunde addressing
Pre-hospital Cooling for Medical Cardiac Arrest. As with his earlier talk, Professor
Sunde gave a measured analysis of the available evidence on timing, technique and
duration for the initiation of therapeutic hypothermia post cardiac arrest. Whilst
data strongly supports therapeutic hypothermia in comatose survivors of cardiac arrest,
it is currently unclear whether pre-hospital or intra-arrest cooling will improve
outcome further. Human studies have not satisfactorily addressed this question but
a beautifully designed rat model of cardiac arrest demonstrated similar survival and
neurological benefit when cooling was initiated between 0 and 4 hours post arrest
and maintained for 24-48 [6]. Professor Sunde summarised by endorsing therapeutic
hypothermia post cardiac arrest but could not demonstrate superiority for its initiation
in the pre-hospital environment.
The London Pre-hospital Care Conference provided an entertaining and informative forum
for the expertise and expanding evidence base in the field. Several speakers called
for more International collaboration in research and major incident planning and,
with its increasing numbers of delegates from many countries, the conference creates
an opportunity for the spread of clinical excellence and for the genesis of such collaboration.
Pre-hospital care remains a dynamic field of medicine and it was a privilege to hear
some of the world’s leading exponents enthuse to an audience who may develop their
own clinical practice in the light of new evidence.