Innovations in Prehospital Care: Could prehospital craniotomy become a thing?

Drilling a burrhole in someone's head to release an extradural haematoma is not neurosurgery. It is a damage control procedure akin to a clamshell thoracotomy being done by any non-cardiothoracic surgeon in EDs (and on street corners) the world over, every day of the year.

There, I said it.

I'm being facetious of course, but the broad point stands. I remember several years back talking to some avid proponents of prehospital craniotomy (or burrholes). One a neurosurgeon, the other an ED physician (its perhaps not insignificant that both were prehospital air ambulance physicians). Both were adamant that in carefully selected patients the early deployment of this procedure could reduce irreversible brain injury in many of their otherwise healthy trauma patients.

The first step is accurate diagnosis of extra-axial intracranial haemorrhage (ICH). Prehospital neuroimaging has been a realistic pursuit for at least 20 years. Mobile Stroke Units (MSUs), which are essentially ambulances kitted out with mobile CT scanners, stroke physicians and neuroradiologists were first utilised in Germany in 2008 and aimed to bring the hospital to the patient, drastically cutting the time taken to restore cerebral perfusion. An RCT  of the German roll-out demonstrated the median time from alarm to treatment decisions being cut in half by MSUs, with only 4% of non-MSU patients receiving thrombolysis inside the ‘golden hour’ compared to 57% of MSU patients.

 But as good as they may be, there is a modality much cheaper and much more portable that can be used without having to first transfer the patient onto a stretcher and into the back of an ambulance. That modality is Near Infrared Spectroscopy (NIRS). One commercially available device, the Infrascanner has been trialled by London’s pioneering Air Ambulance Service with a pilot study in 205 patients screened for traumatic haemorrhage demonstrating a sensitivity and specificity of 75% and 50% respectively, with sensitivity approaching 90% in patients with >3.5ml of intracranial blood. A recent systematic review covering over 2000 patients concluded the modality to be a useful screening tool for ICH, however the jury remains out on whether it could play a role in real-time critical decision-making.

 But let’s assume there is a reliable, portable, easy-to-use device that accurately diagnoses the presence and location of an ICH amenable to treatment via emergency cranial decompression. Several case reports have been published detailing the use of intraosseous needle devices as a temporising measure in emergency departments in both neurosurgical centres and non-specialist general hospitals. Headlines were made in 2009 when an Australian doctor in a rural ED used a drill out of the hospital maintenance cupboard to release an extradural in a rapidly deteriorating 12-year old.

My aforementioned neurosurgery and ED colleagues helpfully published a step-by-step approach for the non-neurosurgeon performing emergency burrholes for cases where there is image-proven or sufficient clinical suspicion of a targetable ICH (i.e. pupil dilation and scalp bogginess). The equipment required is described as “standard” (knife, self retainer, swab, drill, sharp and blunt hock and second knife) and if possible bipolar diathermy. The drill should have a perforator clutch drill bit that automatically cuts out once the skull has been penetrated. All the equipment can be easily stored in any ED or theatre for when needed. After prepping the intended target zone (shave, mark, antiseptic solution) the procedure begins with sharp dissection down to bone, elevation of the periosteum and drilling. The standard location of the burrholes is demonstrated in the figure below taken directly from the paper.

Once the hole is drilled and bone fragments removed any extradural blood should be able to escape. Subdural evacuation requires incising the dura mater as it’s tented between hooks

Taken from Wilson et al.: Emergency burr holes: “How to do it”. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine 2012 20:24.

The Neurosurgical Association of Australasia has also published guidelines for rural surgeons giving a step-by-step guide on localising the site of extradural and subdural haematomas without CT, followed by the emergency drilling of burrholes and craniotomy flap formation. Whether employing a craniotome or Gigli saw, this is a technique that can be honed through training on suitable models and deployed in the field by non-neurosurgeon physicians.

There is clearly a rationale and some evidence to support the practise of early craniotomy prior to arriving in the hands of a neurosurgeon. The only systematic review to look into the topic of skull trephination or cranial decompression prior to transfer to specialist neurosurgical centres found 100% positive outcomes in patients undergoing local haematoma drainage prior to transfer. The bottom line is, when you have a clinical situation approaching 100% mortality that can be treated with the skillset of any General Surgeon (plus a fancy drill), it would be remiss not to provide that treatment. Getting it wrong won’t change the patient’s outcome unless there has been a significant delay in transferring to an easily reachable neurosurgical unit as a result of staying and cosplaying as a neurosurgeon.  

Whether or not this rationale can be extrapolated to the performance of prehospital craniotomy remains to be seen. Similar reservations were probably expressed when ED physicians and anaesthetists on air ambulances started performing prehospital thoracotomies. It will require a brave institution to take that first step, but once they do, it could be an absolute gamechanger.

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He was recently awarded his PhD for his work on optimising the London Trauma System Triage Tool. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone

@drnnajiuba

Rise of the techs

Medical professionals are in danger of being replaced by a talented cadre of ‘technician’ colleagues who are quicker and easier (and most importantly cheaper) to train and able to perform many of the day-to-day tasks of their comprehensively trained colleagues.

For Physicians, read Physician Assistants (PA) and Nurse Practitioners (NP), collectively referred to a "mid-level providers" or "physician extenders". These are common in the United States. For Paramedics it’s Emergency Medical Technicians, anaesthetists have nurse anaesthetists and so on. The PAs were something I first came across on my elective at NYU in 2011. They just weren’t a thing in the UK until recently. Now I find myself delivering lectures on abdominal and chest trauma for their undergraduate degree programmes. My specialist bariatric dietician is currently enrolled on a post-graduate programme which, upon completion, will equip her to assess patients and prescribe medication. I’ve worked with countless NPs who capably fill doctor vacancies in EDs and on the wards, performing at the level of junior residents and becoming integral members of the department.

In the UK, scrub nurses routinely act as first assistants or ‘Surgical Care Practitioners’ when operating with consultants, particularly in the private sector. With the increasing provision of robotic surgery, there is a very pertinent question around how big the surgical workforce of the future actually needs to be. Could 1 surgeon leading a team of techs fulfil all the roles of a traditional medical team or ‘firm’?

 But every cloud has a silver lining and rather than being fearful of what these changes mean for doctors in developed countries, one could instead look to the potential benefits for poorer countries.

In countries such as Mozambique, surgeons take a lead role in training up ‘medico tecnicos’ to be able to perform things like limb amputations and abscess drainage. They follow in the illustrious footsteps of Hamilton Naki, the black South African lab tech who came to be a renowned surgical assistant to Christiaan Barnard, the man who performed the world’s first human-to-human heart transplant in December 1967. Although the degree of his involvement in that famous case are disputed, he was widely respected for his surgical skills and teaching; an art he honed, without formal medical training, on various animal models in the labs. 

A 2010 study of over 2000 emergency obstetric theatre cases in Mozambique and Tanzania found no significant outcome differences in cases performed by surgical technicians and obstetric specialists. Techs were found to be a cost-effective way of addressing staff shortages in rural areas. Their retention in these rural areas, where they were needed most, reached almost 90% at seven years after graduation while the corresponding percentage for medical officers was zero. Similar favourable outcomes have been demonstrated across Sub-Saharan African. Despite reports of their positive impact on population access to surgery, techs face significant challenges including lack of recognition by medical doctors, resulting in marginalisation and loss of motivation. Lack of career opportunities and low salary packages are perceived by them as unfair. A study from Tanzania reported that low motivation among techs, stemming from an experience of low social status and remuneration, was associated with the provision of poor quality of care.

There is a crisis in personnel in Western healthcare which has been deepened over the past year or two by COVID and inflationary pressure on wages which has forced many to leave the professional or seek to earn more overseas. There are also chronic problems with training and retaining doctors in poorer countries with inadequate healthcare setups and crumbling infrastructures accelerating a ‘brain drain’ to the West. In both cases, the solution may be found by empowering and training up a hidden army of enthusiastic and dedicated allied health professionals and technicians to lead the way in providing care for their local communities.

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He was recently awarded his PhD for his work on optimising the London Trauma System Triage Tool. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba

Providing the tool to make bystander haemorrhage control a reality

We used to talk about the Golden Hour in trauma, but in reality, when a person is exsanguinating, every second from time zero counts for something. In cases of penetrating trauma which remains all too prevalent a problem in many urban settings, many lives can be saved with nothing more complex than the application of direct or indirect pressure to stem bleeding, buying time for medical help to arrive.

If a person has a sudden cardiac arrest in a busy train station, airport or shopping mall, you can rest assured that an automatic defibrillator will be within reach. They are simple to use, and members of the public can be talked through the steps by the emergency call handler over the phone.

Taking things a step further, the GoodSam app can be found on the smartphones of many healthcare professionals in the UK. When a cardiac arrest call comes in the emergency call dispatcher can send out an automatic alert to all GoodSam users in the vicinity of the incident enabling them to attend and start lifesaving CPR whilst an ambulance is en-route. I myself have responded to at least 3 such alerts in houses close to where I was. On two such occasions I arrived to find the victims in rigor mortis and a bunch of perplexed relatives wondering who this random guy at their door was claiming to be an off-duty doctor. On one occasion the paramedics had already arrived before I did (the benefits of flashing lights and sirens), meaning my input as a surgical resident who hadn’t run a medical cardiac arrest call in at least 10 years was certainly not required (4H’s and 4T’s right?).

But back to trauma, what if there was a similar EMS-activated first-responder trauma app that not only alerted nearby medics and capable volunteers, but also mapped out the locations of emergency trauma packs? These packs or boxes would be placed in strategic areas of high penetrating trauma prevalence and would contain things like tourniquets and haemostatic dressings. They could also contain a body map highlighting key points at where to apply indirect pressure and maybe even basic i.v. access kits. They could be locked away in a cabinet requiring a code to gain access. This code would be given over the phone by the emergency call handler once the need for such intervention is established. The caller, depending on their clinical experience and confidence could be walked through the process or even have easy-to-follow demo videos sent to their smart device detailing how to apply the dressings or tourniquet as needed. With increasing use of drones there may someday be way of dispatching these trauma first aid packs to the scene of the incident, arriving within minutes. We know that bystander CPR in medical cardiac arrests can triple a person’s chances  of surviving to hospital. Bystander haemorrhage control could do similar, if not better. After all, many of the victims of penetrating trauma are otherwise fit and healthy young men with good physiological reserves.

A couple of years back I touched on the Stop The Bleed campaign in the context of US school shootings. The American College of Surgeons campaign has seen over 2.4 million people worldwide trained in the basics of haemorrhage control since it started around 8 years ago. If we are expecting members of the public and non-clinicians to be able to step in a save lives then they need to be given easy access to simple-to-use tools.  The effectiveness of programs like Stop The Bleed would be enhanced with the ready availability of haemostatic trauma packs located near schools and in other prominent public spaces (especially in areas with a busy night economy). Particular attention needs to be paid to socially deprived areas and within the communities suffering most from the scourge of knife and gun crime. The emergency services can’t be everywhere all the time, but where there are people willing to help, there is always hope that a life can be saved.

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He was recently awarded his PhD for his work on optimising the London Trauma System Triage Tool. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba

Artificial Intelligence in Trauma: The Future of Trauma Systems

The use of artificial intelligence (AI) in maximizing the potential of trauma systems is still in its infancy. Tools that utilise artificial intelligence have yet to move from their pilot phases into real clinical practice. But several machine learning models have been shown in simulation studies to be as effective as existing triage tools in determining trauma center suitability and future iterations may have the ability to learn in real-time from incorrect triage decisions. An inherent flaw in the current triage methodology is that decisions are static and do not incorporate a systematic feedback system enabling triage rules to evolve based on previous wrong decisions. This is the strength of advanced AI which could lead to it revolutionising how we triage and transport the patients of the future.

 Predicting resource utilisation

Imagine an AI system that could use historical data to predict trauma volumes depending on the time of day, day of the week, time of year, major events and even the prevailing weather conditions. It may be able to predict not only trauma volumes but the likely blunt or penetrating mechanisms, anatomical patterns and likely injury severity.

 One could imagine a morning team briefing at the local trauma center going something like “okay team, today’s the day of the state college football finals, based on data from previous years with the weather we have today we can expect anywhere between 4 to 7 alcohol-related traumatic head injuries in males aged 19 to 27 so let’s check our stock of ICP bolts and hypertonic saline. I think it’s worth us running a quick head injury sim to make sure we’re slick. Dr Guerrero, could you liaise early with neuro-ICU…..”

 As the British Army adage of the 7P’s goes: Prior Planning and Preparation Prevents P*ss Poor Performance

 Triage decision-making

 Technology may also have a role to play through the integration of real-time clinical data collected via smart watches and other internet-connected wearable devices.

 In 2018 a Korean team successfully produced a data-driven AI model for prehospital and mass casualty triage which incorporated vital signs from wearable devices. The devices could also detect verbal and motor responses and use that data to generate a modified GCS.

 At some point in the not-too-distant future, ambulance crews may well be able to tap into real-time patient data and accurately determine the need for Level 1 or 2 care.  Based on location and traffic patterns, the optimal means and route of transport could be automatically decided upon prior to dispatch

 The Dutch TESLA trial is currently underway to assess the use of a machine-learning prediction model (the Trauma App) and see how it impacts on triage accuracy, hospital resource use, and a cost-utility. This is something that could soon be incorporated onto the smartphones or devices of ambulance crews.

 Geospatial planning of trauma centre location

There have been several studies looking at the use of geospatial mapping technologies to optimise designation of new trauma centres.

 One such example utilised the American College of Surgeons Needs-Based Assessment of Trauma System Tool (NBATS) which was created by College to help determine the need for trauma centers within a region. In the region surrounding the Elvis Presley Trauma Center (EPTC) in Memphis, the addition of a suburban trauma center resulted in only a 1% increase in population coverage but a steep reduction in patient volumes to EPTC, whereas the addition of 2 rural trauma centers resulted in a big increase in the number of injured people within 45 mins of a trauma center and caused a less significant reduction in patient volumes at EPTC.

 But the capabilities of AI are an enticing addition to tools like NBATS, bringing the ability to account for dynamic population growth, changing traffic patterns, and regional infrastructure. This could dramatically improve trauma system planning and optimize placement of future trauma centers to areas of highest impact.

 The opportunities afforded by increasingly sophisticated AI are limited only by our human imaginations. Time and money invested now could be dividends in future not only in trauma system efficiency but in lives saved.

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He was recently awarded his PhD for his work on optimising the London Trauma System Triage Tool. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba

Surgical Jack of all trades

With the modern tendency towards early sub-specialisation in surgical training, there is something warm and nostalgic in reminiscing back to the old days when a general surgeon was a general surgeon in the truest sense of the word. A few weeks back I was on a weekend round with one of my senior attendings who told me that a regular elective operating list for him as a resident would consist of a thyroidectomy followed by a couple of hernia repairs and finishing with something juicy like an open aortic aneurysm repair. His attending at the time wouldn’t show his face in the OR until my boss had started the AAA repair and dissected down to the aorta. No doubt this style of training tightened sphincters, steeled nerves and with time honed the skills of would-be master surgeons. The old mantra of “feel free to cope” is now often said in jest by my seniors who would once have had it said to them in all seriousness.

 However, the significant harm likely caused to patients cannot be discounted. Furthermore the consequences of such forays were more easily swept under the carpet in the more deferential and less litigious world that our seniors grew up in. The advantages of subspecialisation are obvious and can be extrapolated to the broader centralisation of services such as cardiac surgery to specialist tertiary centers. High volumes and repetition translate to fewer complications, a fact that applies to everything from hernia repairs at the Shouldice Hospital to adrenal surgery across the United States.

 Yet there still remains a place for the true generalist. Perhaps not in heavily-populated and well-resourced metropolitan areas, but more so in the sparsely-populated rural areas, especially in poorer parts of the world given that around 92% of the Earth’s rural population located in developing countries. The bulk of emergency surgery in the developing world is required for the treatment of traumatic injury. This further emphasises the importance of being a true generalist when it comes to trauma surgery. In a previous article I touched on the idea of subspecialist training being at odds with the reality of the skillset required of a trauma surgeon, where anatomical boundaries often go out of the window.

 For many surgeons in training, it’s rite of passage to have spent some time in a high-volume trauma centre in a developing country in Africa or Latin America dealing with the results of violence driven by endemic socioeconomic deprivation. Whilst it may be an exhilarating and worthwhile experience providing stories and anecdotes for years to come, it’s also worth considering the ethics of such practices. Are people in poor countries ok to be the surgical guinea pigs of trainees from rich countries carrying out procedures they may not be trusted to do in their own countrie Surgical training programmes do recognise this desire for a more generalised ‘jack-of-all-trades’ style training. The UK curriculum for General Surgery training sets out an extensive list of competencies expected of those wishing to pursue a specialist interest in Remote and Rural Surgery. These include the kind of crossover surgical skills you’d expect such as Caesarean sections, common gynaecological emergencies and early pregnancy complications. But it also lists emergency craniotomy, maxillofacial fracture manipulation, ureteric stenting and hand surgery among other things. Rural surgery will appeal to many not least because the remunerations for rural physicians are often higher [HN5]  to act as an incentive to draw doctors away from the excitement and bright lights of the city. That along with generous relocation packages, lower living costs and more professional freedoms could make being a rural ‘Jack-of-all trades’ surgeon an appealing prospect.

 Outside of a dedicated training programme it can be difficult gaining the additional skills and experience required to operate outside of one’s subspecialty. I make a habit of joining my obstetric colleagues from time to time for elective caesarean lists, my rationale being as a trauma/emergency surgeon I never know when I’ll have to perform an emergency c-section on a patient. This desire was born of witnessing my own trauma attending do a c-section on a pregnant woman who had been shot be jealous ex-partner with a crossbow. My current bosses would much rather I spent the extra time in endoscopy or operating as a general surgeon, however we all have the right to exercise a degree of autonomy over what we learn along the way

 I used to have dreams of getting some anaesthetic training and spending some time flying out with London’s Air Ambulance Service (European air ambulances tend to fly with doctors and operate quite differently to American services, as detailed previously in this blog). The realities of a fast-paced and competitive training treadmill with boxes to tick and set numbers of procedures to be signed off on means there is little opportunity for me and many others to branch out.  Add to that a long-suffering wife steadily losing patience with the lifestyle and shift patterns of a resident

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba

Injuries in COVID: a changing pattern

Urban dystopia

One of the frequent topics of discussion in the coffee rooms of my busy district general hospital (which serves almost a million people on the outskirts of London) has been the relative lack of ruptured AAAs coming through the ED over the past year or two. Given that on a typical day of emergency operating I can find myself doing 4 or 5 laparotomies for a number of weird and wonderful pathologies, the absence of ruptured AAAs seems something of an anomaly. The commonly held theory in our unit is that COVID took the lives of most of the folks likely to have been brewing these vascular emergencies. The co-morbidities that led the to development of their aneurysms will have also made them most susceptible to the ravages of COVID. There can be little doubt that the global pandemic has had a significant and enduring impact on the demographics and outcomes of emergency admissions across all specialties, not least in trauma.

 With lockdowns in place, road-traffic collisions decreased as expected, with one LA trauma centre reporting a 43% reduction in the automobile versus pedestrian admissions, a near 40% reduction in motorcycle injuries and a 28% decrease in bicycle accidents.  Similar reports emerged from places such as New Zealand, Italy and Canada suggesting fewer sports-related and traffic-related traumas in the weeks following lockdowns compared to similar time periods prior to lockdowns. A study from the heavily-hit Lombardia region of  Italy showed a significant increase in elderly falls as the trauma demographics shifted. There was a seven-fold increase in ‘intentional falls’ i.e. suicides and significant increase in deliberate self-harm as the compound psychological traumas of close bereavement, social isolation and economic hardship tipped at-risk people over the edge. These findings are mirrored elsewhere, with the aforementioned LA group reporting a 40% increase in suicides.

 Unsurprising, outcomes in COVID-positive trauma patients differed significantly. Some groups reported higher mortalities in surgical patients infected with COVID, a pattern noted across all specialties and in both elective and emergency surgery. Kaufmann et al in Pennsylvania showed a threefold adjusted increase in mortality in COVID -positive patients, with the over-65s and least severely injured being most at risk.

From Lombardia to California to Texas, widespread reconfiguration of regional trauma systems was required to maintain service capacity. In some cases such as Lombardia this involved greater system exclusivity with trauma services and staff consolidated at fewer dedicated high-level trauma centres, thus increasing the proportion of trauma patients they saw despite an overall reduction in absolute numbers. In some ways a contrasting situation unfolded in New York City where lower-level trauma centres were unable to transfer patients to Level 1 centres because of the knock-on effects of ICU beds saturated with COVID patients. In London the triage tool was streamlined to ensure more patients could be safely admitted to their nearest ED rather than clogging up the Major Trauma Centres. Universally, elective lists were cancelled, operating rooms were converted to critical care units and new standard operating procedures introduced for high-risk procedures such as intubation.

In contrast to the reduction in blunt RTC-related trauma, an increase in penetrating trauma and interpersonal violence was noted in a number of urban centres across the country. In Philadelphia, Quasim et reported an increase in penetrating trauma from a baseline of 29% to 35% following lockdown, despite an overall 20% reduction in trauma admission numbers. Several factors may explain this pattern. The inability for the poorest in society to work from home combined with the psychological stress of the pandemic may have contributed. Other possibilities include the increase in unstructured time, increased gun sales, and higher rates of redundancy and unemployment. Put simply, highly populated poor neighbourhoods which were most susceptible to the worst impacts of COVID saw a similar increase in violence owing to shared risk factors.

 For future pandemics urban trauma centres should perhaps prepare for a significant increase in violence and penetrating trauma, which kind of fits neatly in with what you’d imagine a dystopian apocalyptic cityscape to look like in any disaster movie you care to name.  Whilst we as health professionals may not be able to directly tackle the socioeconomic issues behind the phenomenon, we can anticipate and mitigate its impact.

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba

Wrestling with the pig(tail) debate

To this day I still smugly remember the time when as an intern on my respiratory medicine rotation (or house officer as we still often to call it in the UK) I tried to teach the respiratory med resident how to put in a ‘proper’ chest drain in a patient with a large pneumothorax. I meant ‘proper’ as opposed to what I deemed at the time to be the silly little pigtail catheters he was more accustomed to. At this stage in my fledgling career I was already a fully paid up trauma junkie having attended numerous student trauma conferences and having spent a month at Bellevue/NYU Langone as a sub-intern on trauma surgery during my final year at med school. With the misguided confidence (arrogance) of youthful inexperience I went on to subject my unfortunate geriatric patient (victim) to a bloody 20-minute ordeal that left the patient, the resident and other patients in the bay who heard the screams all traumatized in equal measure. Unfortunately for the patient it turned out to be an entirely futile procedure with his pneumothorax not resolving and subsequent CT imaging showing that I had managed to put the tube perfectly into the oblique fissure of the left lung, abutting the mediastinum.

Looking back I think my enthusiasm for finally getting to put in a large bore chest drain (let’s say size 28 Fr upwards) stemmed from my instinctive distrust of the smaller pigtail catheters (9-14 Fr) which I’d seen used to treat chronic effusions secondary to medical conditions, but which I didn’t fancy as being effective for treating traumatic pneumo/haemothoraces. The whole Seldinger thing looked too fiddly and time consuming compared to the scalpel and stiff finger needed to rapidly put in a trauma chest drain. And intuitively I just didn’t see how such a small caliber tube could handle clotting blood. Like needle pericardiocentesis for cardiac tamponade, it just seemed woefully inadequate for the task at hand. And it would seem that my misgivings were backed up by a large number of people in the trauma field with far more knowledge and experience than I had.

Over the years a number of observational studies have attempted to show that small pigtail catheters and large-bore chest drains are equals in terms of effectiveness and complication rates, and if anything the pigtails cause less pain and are therefore arguably superior. Unfortunately these studies were usually underpowered to detect significant differences between the groups, suffered from poor design and were susceptible to selection bias in terms of the patients allocated to pigtail or chest tube insertion.

A 2018 systematic review and meta-analysis from a Taiwanese group looked at 11 studies comprising almost 900 patients comparing pigtail catheters with chest tubes for treatment of pneumothorax. Only 2 of the papers analyzed dealt specifically with the case of traumatic pneumothorax (one an RCT of only 40 patients and the other a retrospective study- both from the same Arizona group). Overall they showed no significant differences in success rates, complication rates, or drainage duration between the two types of chest drains although they conceded that a proper RCT would be needed to add weight to the conclusions.

A single-center and multi-center RCT published last year (again from the Tuscon group) showed similar findings of no significant differences in failure rates, daily drainage output, tube days, intensive care unit and hospital length of stay. And both reported a more favourable patient experience with the use of the smaller pigtail catheters. Again, the patient numbers bring into doubt the validity of the findings with only 43 patients randomized in the single-center study and 119 in the multi-center study, in both cases falling short of the authors’ own targets based on their power calculations. Having said that, these RCTs are baby steps towards building a more solid evidence base in favour of a procedure that may be more tolerable for patients whilst not being inferior to the traditional methods.

The big unanswered question is whether insertion of a pigtail catheter is practical and effective in the trauma patient presenting to ED in extremis. EAST practical management guidelines were updated last year to recommend pigtail catheters in favour of large bore drains for treating traumatic haemothorax in stable patients, however the guidelines still acknowledge the fact that that chest tube thoracostomy remains the preferred choice in emergent situations where the patient is unstable. On that matter, aren’t most people who need an ED chest drain for a haemothorax in some degree of haemodynamic instability? In which case how large is this target population of stable haemothorax patients whose bleeds have not consolidated into a clot too thick to drain easily out of a pigtail catheter?

Ultimately it still comes down to what feels like the right decision to make for the patient in front of you. An isolated haemo or pneumothorax in a clinically stable alert patient may well warrant a pigtail catheter if the person inserting it is familiar with the technique, however this may not be the sensible option in a crashing polytrauma patient with a liter of blood in their chest. From our very first day as interns we all started to subconsciously accumulate knowledge and experience that would shape our attitudes and decision-making going forward. One can only hope that years of first-hand experience and evidence trump the excesses of youthful exuberance.

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba

Innovations in prehospital care: Blood transfusion and haemorrhage control

Sometimes in medicine, what may seem like a new concept is simply a reboot of an old one with the additional bells and whistles that advancements in technology allow. The subject of resuscitating bleeding patients in the field is one such example. The 17th century findings of William Harvey cemented the importance of blood circulation to the brain and other vital organs. The following centuries have seen the development of transfusion practices that have shaped how we resuscitate sick and injured people in need of blood products.

 As ever in trauma, much of what we do now is a result of lessons learned on the battlefields of the last century. World War 1 saw US forces pioneering the transfusion of whole blood. The Second World War continued in this fashion but also saw a shift towards the use of freeze-dried plasma and albumin as alternative volume replacements. Wastage of blood products in the Korean War led to a renewed impetus in US military research into alternative blood products and ways to increase the shelf-life of existing whole blood units.

For Vietnam, crystalloid was back in fashion, but also around the same time, blood fractionation techniques meant that individual components could more easily be given. Frozen red blood cell (RBC) units were trialled, but the thawing and preparation process proved to be resource-intensive, limiting the utility of this strategy.

 By the time of the Iraq and Afghanistan conflicts of the early 21st century, an improved understanding of traumatic coagulopathy, the potentially harmful effects of excess crystalloid and the protective effects of plasma on vascular endothelium resulted in a push towards targeted higher ratios of fresh-frozen plasma (FFP) and platelets to RBC.

 Current civilian damage-control resuscitation principles, borne of over a century of military experience have spilled over to the prehospital arena with many EMS services now having the will and capability to deliver prehospital blood product transfusions. Studies have demonstrated the feasibility of prehospital blood transfusions despite there still being a relative dearth of level 1 evidence in its support. The multicentre PAMPer study demonstrated a potential survival advantage in patients receiving prehospital plasma resuscitation whilst experience from London HEMS also demonstrated a significant reduction in prehospital mortality in patients receiving prehospital packed red cells. The evidence for its effectiveness notwithstanding, there are practical hurdles that also must be considered in terms of co-ordination with blood banks and supply and storage limitations

 But blood transfusion is just one part of the haemostatic resuscitation package, and as the mantra goes, pouring water in a leaking bucket is ultimately futile. Temporising measures to stop bleeding in the prehospital environment have also benefited from military invention and/or refinement. Wound packing with haemostatic dressings and or tourniquet control of peripheral vascular injuries have been standard treatments for many years (if not centuries in the case of tourniquets). A number of innovations to tackle junctional and more central blood loss are also available on the market. The Combat Ready Clamp (CRoC) is a clamp that provides bidirectional pressure and can be applied to the iliacs, axilla and umbilicus to provide direct lower aortic compression. The SAM junctional tourniquet closely resembles the company’s pelvic binder but has the additional of 2 inflatable ‘Target Compression Devices’ which provide additional control of groin and (with the necessary strap adjustments) can also be used for axillary bleeding. Meanwhile the Junctional Emergency Treatment Tool (JETT) is an almost CroC-SAM hybrid with its adjustable groin compression pads fixed to a waist belt.

 Ultimately it may be totally impractical to expect to deliver prehospital mass transfusion and the key may be quick and accurate identification of the bleeding source, with targeted haemostasis in-transit alongside pharmacological organ protection.

 So no need for a prehospital version of our awesome MTP Scorekeeper just yet.

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba

Innovations in prehospital Care: ECMO

Sophisticated European-style ECMO in the Louvre, with Zeng Fanzhi’s 1830 Until Now in the background

What is ECMO?

Extracorporeal Membrane Oxygenation or ECMO is a type of cardiopulmonary bypass for providing prolonged cardiac and respiratory support to persons whose heart and lungs are unable to provide an adequate amount of gas exchange or perfusion to sustain life. The key differences between ECMO and the traditional forms of cardiopulmonary bypass used in cardiac surgery are that the latter requires transthoracic cannulation typically done under general anaesthesia and for only a few hours during surgery, whilst the former can be done with more peripherally sited central access (i.e. femoral or cervical vessels) and can remain in place for several days allowing for intrinsic recovery of damaged lungs and heart. ECMO at its simplest is a pump and oxygenator working in tandem to supply the patient’s circulation with oxygenated blood. It exists in two broad forms with venovenous (VV-ECMO) providing only lung support and venoarterial (VA-ECMO) providing both respiratory and haemodynamic support with the circuit connected in parallel to the heart and lungs.

 ECMO’s development throughout the 70s was largely driven by the need to temporarily support infants with respiratory failure due to congenital heart defects. Since then, the scope of its use has continued to grow to the point now that in some European cities it has been routinely being taken out into the prehospital environment to support selected patients in cardiac arrest.

The Parisian Model

In cardiac arrest, VA-ECMO (in this setting more commonly referred to as ECPR- Extracorporeal cardiopulmonary resuscitation) is performed. The setup in Paris, (which has become the benchmark for out-of-hospital ECPR for over 10 years) is perhaps the most widely known. The Parisian EMS known as SAMU (Service d'Aide Médicale Urgente) regularly dispatch Mobile ICU units (MoICU) to scenes where advanced medical care and patient stabilisation are required, be that a suspected aortic dissection, major stroke or cardiac arrest. The MoICU team typically comprises an emergency physician/anaesthetic-intensivist, a nurse and a paramedic. Having been deployed to the scene by a dispatch physician screening emergency calls at the EMS control centre, the MoICU take over the resuscitation started by the regular fire department EMS who are usually first on the scene. If after 10 minutes ROSC is not achieved, and the patient is deemed suitable for ECPR (i.e. witnessed cardiac arrest in a patient aged under 70) the MoICU will call for the ECPR team who themselves will have already been on standby from the initial emergency call. The ECPR team has a similar setup to the MoICU with an anaesthetist-intensivist, an anaesthetic nurse and paramedic typically on the team. The ECPR and MoICU teams work in tandem (physicians doing the cut-down/Seldinger hybrid technique to gain femoral vascular access, nurses priming the ECMO and drawing up drugs, paramedics assisting the physicians and handling kit). This is the very antithesis of ‘scoop and run’. And the results speak for themselves with survival and good neurological outcome reported in almost third of out of hospital cardiac arrests. Prospective studies in cities such as London (in collaboration with London’s Air Ambulance) are ongoing to establish the wider feasibility and likely outcomes of pre-hospital ECPR.

 ECMO in trauma

The traditional role of ECMO in trauma since the 1970s has been VV-ECMO for the adjunctive treatment of refractory respiratory failure in ARDS, TRALI and the like. The use of VA-ECMO/ECPR in the haemorrhagic shock and traumatic arrest patient is a much more novel and controversial proposition. The AAST stance on the matter remains fairly equivocal, essentially leaving it up to individual ECMO centres to do as they please. There have been a number of case reports and series from Asia of successful ECPR as a bridge to definitive surgery in patients who have arrested from traumatic ventricular rupture, cardiac tamponade and tension pneumothoraces. When we think about traumatic coagulopathy and vicious cycles it seems intuitive that ECMO has an important role to play. Simultaneous extracorporeal warming of blood, transfusion of blood products and depleted clotting factors can all take place with the patient on ECMO as part of the damage-control resuscitation continuum. The reduction in venous pressure from large bore cannulation may help to reduce bleeding and as techniques and technology continue to advance there may be scope for selective anatomical exclusion of injured solid organs from the patient’s circulation pending surgical repair. Indeed, ECMO in trauma is intrinsic to the success of suspended animation, a topic discussed in this very blog only a few months ago. Unanswered questions remain about the ideal candidate for ECMO in trauma. Consider also that a large percentage of blunt polytrauma that leads to arrest has a concomitant traumatic brain injury, which as with resuscitative thoracotomy would be a contraindication for specialist resource-intensive interventions such as ECMO.

 A further consideration is the question of anticoagulation. In the non-trauma setting, systemic anticoagulation is generally a given due to the risk of thromboembolic events in the patient and the ECMO machinery itself. However, in trauma ECMO, given the inherent injury-related bleeding risk several strategies have been employed including full heparin systemic anticoagulation, a heparin-minimised strategy, all heparin-free, initially heparin-free and delayed heparin-free treatments. Whilst several series have reported no thromboembolic complications with heparin-free ECMO, hope remains that technological advancements including the use of more efficient membrane oxygenators, centrifugal pumps, miniaturisation of circuits, and heparin-bonded circuitry will eventually allowed ECMO use with little or no anticoagulation.

 The Future

The inevitable next stage in ECMO’s evolution is its incorporation into prehospital trauma care. Perhaps as a last-ditch salvage technique when thoracotomy and even REBOA may prove futile. One would imagine the results could be promising. On the whole trauma patients are younger and fitter than the stereotypical medical cardiac arrest patients who come with their usual cardiovascular and lifestyle risk factors. Furthermore, trauma patients are likely to sustain their injuries in a public urban setting (e.g. road traffic accident or a witnessed assault violent incident) and therefore help will be summoned quickly, minimising downtime and thus increasing the likelihood of success. Further prospective studies are needed, not least because traumatic arrest has often been an exclusion criteria in the few ECPR studies to date. The clinical and technical skills involved can be easily taught. As ever it is likely to be the financial and political will that proves the rate-limiting step.

Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba

Pre-Hospital Surgery

The first prehospital thoracotomy performed by London’s air ambulance service outside an Indian restaurant on Christmas Eve 1993

Preshospital surgery, once seen as fanciful, perhaps even reckless is now a normal occurrence in parts of the world.

 The headline act has to be the prehospital resuscitative thoracotomy. Ironically, the world’s first successful prehospital thoracotomy was performed in Houston in 1988 by Matthew J Wall M.D., then a senior surgical resident who was riding along with the Houston Fire Department EMS as a physician-observer. Yet, despite being pioneers in the field, American EMS services have never embraced the procedure as a part of their on-scene armamentarium. Indeed, the idea of putting doctors out in the field remains something of an anathema.

Other services around the world have led the way, most notably London’s Air Ambulance services (also known as HEMS- Helicopter Emergency Medical Service). London HEMS is renowned for its innovative culture and have embraced new technologies that allow them to bring the resus bay, OR and ICU to the patient. There is a realisation that the ‘stay and play’ school of thinking almost certainly has a place when it comes to dealing with the exsanguinating patient in extremis.

London HEMS operates a helicopter by day and a fleet of cars by night as London’s narrow streets and ample obstacles prevent safe night-landing. The teams comprise 1 or 2 specialist prehospital physicians alongside a flight paramedic seconded from the regular London Ambulance Service (LAS). Emergency calls to LAS HQ are screened 24/7 for suitability for HEMS dispatch. Certain injury patterns or mechanisms will trigger an immediate dispatch i.e. penetrating central chest injury, falls from significant height or person under a train. Other times the call may be interrogated by a dedicated HEMS paramedic at the call centre to ascertain suitability. Regular EMS crews are also able to request HEMS attendance once they arrive on scene and the picture becomes clearer. The team is dispatched from their home base atop the Royal London Hospital in the city’s East End. The service also forms a key part of London’s Major Incident response plan. The physicians are for the most part ED or anaesthesia/ICM trainees or consultants (attending physicians), however historically a steady stream of surgical residents (often with military backgrounds) have brought their skillset to the mix. Surgical leadership in the training of prehospital physicians is crucial for obvious reasons. The unit’s Clinical Lead is Karim Brohi, world-renowned Professor of Trauma Surgery who himself was a HEMS flight physician in his residency years.

Prof Karim Brohi and a HEMS crew atop the Royal London Hospital

So, is prehospital thoracotomy a procedure worth doing? A 2011 case series of 71 prehospital thoracotomies carried out by the London HEMS service produced 13 survivors (18%), with good neurological outcome in 11 of the 13. This success rate is in keeping with survival rates of 21% for emergency department thoracotomy in penetrating trauma patients with signs of life reported in a large US systematic review in 2015.

Prehospital thoracotomy is just one of the advanced capabilities brought to the scene by HEMS. The ability to perform emergency anaesthesia, administer blood products, antifibrinolytics and reverse anticoagulants all add to an advanced capabilities the team can bring to the most severe of trauma cases.

One of the more recent innovations is prehospital REBOA (Retrograde Endovascular Balloon Occlusion of the Aorta), which effectively replaces the need to perform thoracotomy for distal haemorrhage control (i.e. abdominal and pelvic haemorrhage). The operator gains access to a femoral vessel using a standard ultrasound-assisted Seldinger technique then sites a balloon catheter at a suitable location within the aorta before inflating. Patients routinely arrive in the OR with the REBOA balloon in-situ. An ED doctor or suitably trained REBOA operator takes the reins and works with the trauma surgeons on table to deflate or re-inflate the balloon as required whilst damage-control surgery is underway.

The ability to perform such daring feats in the prehospital arena which then blend seamlessly into the in-hospital environment relies not just on innovation but senior institutional buy-in. Hospital chiefs and program directors must be on hand to provide political and medicolegal cover to the doctors out in the field performing procedures that traditionally had no place being performed outside of a hospital. No one is suggesting that having an anaesthetist open a chest in a dark alleyway is preferable to having a trauma surgeon do so in a well-lit fully equipped OR. However, when faced with the choice of almost certain death vs a 20% chance of survival, I know which option I’d choose for myself or anyone I cared about. Training and experience are key, as is the development of standard operating procedures that detail the suitable target patient population for the procedures available.

Future trials of new devices and pharmacological adjuncts are to be expected including prehospital ECMO, which has been used outside of hospital in other European countries, most famously in the Louvre in Paris.

Steve Jobs once said that innovation is the ability to see change as an opportunity- not a threat. US institutions would do well to embrace a more innovative outlook when it comes to prehospital care and continue to legacy that was started in Houston in 1988.

 Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.

@drnnajiuba