Prehospital management of pelvic fractures

Will a pelvic binder help this?

Will a pelvic binder help this?

In the New Zealand trauma setting, blunt trauma is by far the most common mechanism. In the Auckland region it is not uncommon for us to manage patients with major pelvic trauma in ED (most commonly as a result of road trauma), and with the advent of the HEMS service our team are now dealing with this in the prehospital setting as well. The most notable case transported by the Auckland HEMS service in the last year involved a middle aged patient with a free-floating pubic symphysis (open bilaterally with actively bleeding groin wounds), a sacral fracture, and an ED arrival blood pressure of 66/40…)

This paper, published in 2007 by a UK trauma service, provides a nice overview of the prehospital management of pelvic trauma.

Take-home messages:

  • In patients who are obtunded (and therefore have an utterly unreliable clinical assessment) a pelvic fracture should be assumed to be present and a splinting device placed
  • in conscious patients, the presence of pelvic pain is a more reliable indicator of a fracture than palpation or compression of the pelvis
  • Reduction and stabilisation of pelvic fractures should occur as soon as possible after injury, while clotting mechanisms are still intact
  • Bleeding from pelvic fractures should be considered to be non-compressible, and therefore permissive hypotension (resuscitation to the presence of a radial pulse only) should be considered as a resuscitation strategy; NICE guidelines recommend 250mL boluses titrated to the radial pulse
  • There is a risk of patients becoming haemodynamically unstable following full log-rolls for spinal assessment (this has been reported in the ED setting); in the prehospital setting a roll to 15 degrees only will allow placement of a scoop
  • the handover to medical staff in ED should include advice not to remove the splint until a significant injury is excluded, including the fact that pelvic splints can provide excellent anatomical reduction leading to fractures potentially being missed and displacing once the splint is removed

The following is an instructional video showing the use of the SAM Sling, which is carried as standard kit on our helicopters:

 

 

Prehospital Management of Traumatic Brain Injury

extradural-haematoma

To date, the most significant procedural capability the the addition of doctors to the ARHT Westpac Rescue Helicopter has provided has been RSI capability. Of the RSIs performed so far,  a significant proportion have been for severe traumatic brain injury (TBI).

With the exception of surgical intervention (which is required in a minority of cases of severe TBI), most other essential elements of severe TBI management can be provided in the prehospital setting – airway protection, optimisation of oxygenation, prevention of hyper- or hypo-carbia, support of cerebral perfusion pressure, and ICP control.

This paper, published in the Journal of Neurosurgery in 2008, reviews the evidence around the various elements of the pre-hospital severe TBI care ‘package’.

Take-home messages:

  • a period of hypoxia (PaO2<60mmHg) is associated with a 50% mortality rate and a 50% severe disability among survivors
  • in previous studies hypoxia has been a common complication of prehospital intubation for severe TBI, with up to 57% of patients experiencing transient hypoxia lasting a mean of 2.3 minutes (note – these studies frequently involved neither an RSI as we know it nor personnel who were appropriately trained and qualified; more recent evidence points to a benefit for prehospital RSI for severe TBI provided it is done well by appropriate people)
  • Tight control of CO2 after intubation has a significant effect on survival – in one large series patients with normal CO2 on arrival to ED had a 21% mortality, those with CO2 outside the normal range had a 34% mortality
  • Manual ventilation is associated with hypocarbia
  • A single episode of hypotension (systolic BP less than 90mmHG) doubles mortality
  • Management of hypotension in the field improves outcome
  • Transport by helicopter for patients with severe TBI improves odds of survival compared with ground transport (OR 1.6-2.25) – this may reflect the presence of more skilled personnel on the helicopter, careful attention to post-intubation ventilatory parameters, and transport to a trauma centre.

Have we been taught all wrong?…A new location of needle decompression?

Where do you insert the needle for pneumothorax decompression?

Easy!

Is it time to rethink 2nd intercostal space, mid clavicular line for site of needle decompression?

Is it time to rethink 2nd intercostal space, mid clavicular line for site of needle decompression?

“2nd intercostal space (ICS), mid-clavicular line (MCL)” – this has been drilled into all of us since we began training and caring for critically ill patients. Ever since we began as pre-hospital care providers or took our first  Advanced Trauma Life Support have we used the 2nd ICS, MCL and assumed it to be optimal.

Well recently some studies have started looking at whether we should consider an alternative location. There is some evidence to suggest that the traditional anterior approach may reduce kinking and in the combat environment, it might be preferred (Beckett A et al. J Trauma 2011). However, if it will never enter into the pleural space then kinking becomes irrelevant.  While the utility of needle decompression vs. simple finger thoracostomy followed by chest tube insertion can be debated, in the pre-hospital setting, needle decompression remains within the realm of paramedics and may at times be most practical. Also, unless you’re rapidly prepared to perform a chest tube with sterility in mind, needle decompression may be a better option. Thus, such studies remain important.

A recently published study (from the USC trauma surgeons in Los Angeles who seem to publish everything related to trauma) compared the 2nd ICS , MCL with the 5th intercostal space, anterior axillary line (AAL).

CT chest exams of 120 trauma patients were used in the study. Measurements were taken at both sites and compared. Interestingly, the authors stratified patients into 4 BMI categories then analyzed the data based on these groupings.

Results

  • Overall, the 5th ICS AAL was a superior site for needle decompression based on chest wall measurement
  • Chest wall thickness was thicker at the 2nd ICS MCL compared to the 5th ICS AAL (by 0.5cm)
  • As only 16% of patients had chest walls thicker than the standard 5cm needle commonly used. Compared to 42% probable failures if placed at the 2nd ICS MCL.
  • Based on BMI stratification, needle decompression at the 5th ICS AAL would be possible for all but the highest BMI while at the 2nd ICS MCL would likely fail except in the lowest group

Take home message – given this was not a clinical study (only based on CT scans) it’s not quite practice changing. We don’t know the potential risks of cardiac injury using the 5th ICS AAL or whether it can be feasibly performed without kinking. However, this technique could be considered if the 2nd ICS MCL fails, especially in high BMI patients and clearly any benefits outweigh the risks – for instance if the patient has already arrested.

STUDY ABSTRACT

Inaba K et al Radiologic evaluation of alternative sites for needle decompression of tension pneumothorax. Arch Surg 2012;147:813-8

OBJECTIVE: To compare the distance to be traversed during needle thoracostomy decompression performed at the second intercostal space (ICS) in the midclavicular line (MCL) with the fifth ICS in the anterior axillary line (AAL).

DESIGN: Patients were separated into body mass index (BMI) quartiles, with BMI calculated as weight in kilograms divided by height in meters squared. From each BMI quartile, 30 patients were randomly chosen for inclusion in the study on the basis of a priori power analysis (n = 120). Chest wall thickness on computed tomography at the second ICS in the MCL was compared with the fifth ICS in the AAL on both the right and left sides through all BMI quartiles.

SETTING: Level I trauma center.

PATIENTS: Injured patients aged 16 years or older evaluated from January 1, 2009, to January 1, 2010, undergoing computed tomography of the chest.

RESULTS: A total of 680 patients met the study inclusion criteria (81.5% were male and mean age was 41 years [range, 16-97 years]). Of the injuries sustained, 13.2% were penetrating, mean (SD) Injury Severity Score was 15.5 (10.3), and mean BMI was 27.9 (5.9) (range, 15.4-60.7). The mean difference in chest wall thickness between the second ICS at the MCL and the fifth ICS at the AAL was 12.9 mm (95% CI, 11.0-14.8; P < .001) on the right and 13.4 mm (95% CI, 11.4-15.3; P < .001) on the left. There was a stepwise increase in chest wall thickness across all BMI quartiles at each location of measurement. There was a significant difference in chest wall thickness between the second ICS at the MCL and the fifth ICS at the AAL in all quartiles on both the right and the left. The percentage of patients with chest wall thickness greater than the standard 5-cm decompression needle was 42.5% at the second ICS in the MCL and only 16.7% at the fifth ICS in the AAL.

CONCLUSIONS: In this computed tomography-based analysis of chest wall thickness, needle thoracostomy decompression would be expected to fail in 42.5% of cases at the second ICS in the MCL compared with 16.7% at the fifth ICS in the AAL. The chest wall thickness at the fifth ICS AAL was 1.3 cm thinner on average and may be a preferred location for needle thoracostomy decompression

The first ARHT case-based learning session!

This past week, we conducted the first ARHT case-based learning session for the duty crew!

While “case-based learning” may seem like a bunch of educational jargon…it can be rephrased to “sit around the table, discuss a previous job and consider the “what if” “.

I think at this point I was trying to convince people that I wasn't full of BS!

I think at this point I was trying to convince people that I wasn’t full of BS!

We assembled the team for the day which included the crewman, paramedic and doctor for a 45-50 minute session in the board room.  A huge thanks to Russell C, Leon, and Scott O. who all participated and they generated a great discussion about several aspects of this case. (next time we’ll be looking to get our pilot involved too!)

I had the opportunity to facilitate the session which was based on a relatively straight forward job that I had selected. The job involved a patient with a head injury and the focus was on the management of traumatic brain injury in the pre-hospital setting. But amazingly, the discussion covered tons of ground and we discussed all different aspects from before we leave the base, to the time we arrive at the hospital. Much of the discussion focused on CRM ideas which was very interesting.

Our team's paramedic and crewman in deep thought! We must have just been getting to the interesting part! At least the team isn't asleep!

Our team’s paramedic and crewman in deep thought! We must have just been getting to the interesting part! At least the team isn’t asleep…

Here’s a summary of our lively discussion!

Pre-job briefing: unless it was a water job (or extra equip is required) that this could/should be done en route
On scene time: Something we need to address as a team given some growing evidence that scene time doesn’t impact mortality in blunt trauma
Decision making for RSI: time to hospital played considerable role in whether to perform an RSI
Role assignment in RSI: crewman should probably be tasked with RSI checklist and scene management rather than involved in being hands-on during RSI. The doctor should hand the bougie & endotracheal tube to paramedic though  good discussion resulted about this and may be situation dependent
Team position in flight: discussion whether person who intubated should remain at head of bed (even if it was MD) during flight. Consensus that if patient is requiring infusions etc…then MD should be at the side, with paramedic at the head and crewman to his right.

We’ll be looking to roll out a few more sessions in the new year.

Some feedback from the session regarding logistics

  • Using previous jobs to generate discussion is good
  • Focus will be on picking jobs at random to improve learning but this will NOT be a means of quality assurance or control
  • Short sessions will be the goal: 20-30 minutes
  • Getting the whole team together is best, that includes the pilots!
  • All members felt this was a valuable exercise and would participate in future sessions

Again, thanks to the duty crew that day and Scott O for the pictures. See you all in the New Year.

Errors in prehospital paediatric resuscitation

paeds

When compared to adult resuscitation, paediatric resuscitation has anatomical, pharmacological, procedural, social, and emotional differences that may make it more difficult and therefore more prone to error.

The authors of this study (full text pdf – NOT hosted on this site) used a simulated paediatric emergency (infant with altered mental status, seizures, and respiratory arrest) to look at errors in paediatric resuscitation by two person EMS teams.

What emerged were issues regarding equipment familiarity/use/misuse, failure to check BSL, and drug errors. Calculations of drug doses were difficult under stress. Failure rates in some of these domains exceeded 50%.

This study, coupled with our low incidence of significant paediatric resuscitation, suggests that we must have ongoing training in paediatric emergencies (simulation and otherwise) to mitigate these risks, and consider new ways of avoiding error. Given the high rate of smartphone use by HEMS personnel, this app is possibly a good start!

 

Oxygen physiology and pulse oximetry lag podcast

corpuls

This podcast, from the Scott Weingart’s superb emcrit.org site, discusses the lag between oxygen delivery commencing following RSI and the rise in saturations on the patient monitor. It is directly relevant to the prehospital setting, given that a colder environment and a shocked/underresuscitated patient results in a longer pulse oximetry lag. The discussion also makes note of several cases where a (probably) successfully placed ETT was removed in the prehospital setting due to pulse oximetry lag.

The emcrit show notes are here

The podcast is here

 

Motion sickness

airsick

Motion sickness among aeromedical staff is an important factor that may limit our ability to deliver effective in-flight patient care. Having experienced this once in the helicopter (an aerial search of the bays of the Manukau Harbour in gusty winds is not an excursion I would recommend to anyone wanting a sightseeing flight!), I can say that it is truly debilitating.

The Emergency Medical Retrieval Service of Scotland have a published SOP relating to air-sickness, including practical non-pharmacological methods of improving symptoms.

A detailed discussion of motion sickness from Medscape can be found here

Algorithm for traumatic cardiac arrest

tension

While traditional teaching is that resuscitation on scene in traumatic cardiac arrest is futile, recent studies have demonstrated higher survival rates than previously thought.

The authors (UK emergency medicine and aeromedical specialists) of this paper have reviewed the literature regarding traumatic cardiac arrest and generated an algorithm that is applicable to both pre-hospital and hospital settings.

“The algorithm aims to rapidly identify and correct reversible causes of TCA. Transport of TCA patients from the pre-hospital to hospital setting with on-going cardiopulmonary resuscitation is usually futile and key interventions need to be performed as soon as possible, usually on-scene. Patients arriving at a hospital in traumatic peri- or cardiac arrest need reversible causes immediately excluded and managed prior to transfer for diagnostic imaging or surgical intervention. The treatment priorities in this algorithm have been applied by a physician-led pre-hospital trauma service to over a thousand TCA’s attended over an eighteen year period. Published results demonstrate that adherence to these principles can result in good survival rates from TCA.”

The algorithm focuses on treatment of reversible pathology that may have led to an arrest:

  • Correction of hypovolaemia
  • Oxygenation
  • Decompression of tension pneumothorax
  • Thoracotomy in the setting of penetrating chest/epigastric trauma
  • Consideration of non-traumatic causes of cardiac arrest

Full text pdf of this paper is available here (secure area limited to ADHB staff only – ADHB has online subscription access to this journal via the Philson Library at the University of Auckland School of Medicine)

Ever done an RSI in a helicopter? Here’s a recent simulation experience!

Recently at the base, we’ve been discussing the concept of improving our ergonomics and making our workspace (e.g. the helicopter) as functional as possible. We are continually looking to optimize our equipment to best serve our patients.  Any procedure in-flight will be considerably more difficult than if performed in a well controlled environment like the hospital so in-situ training within the helicopter is essential.

Today, Karl (one of our advanced paramedics) and I did some in-situ simulation of an RSI within the helicopter. We ran through a scenario with an unpredicted deterioration of a patient in flight that required an RSI. A review of the literature provides little guidance on the emergency airway management of patients while in-flight so approaches to such situations currently must be derived from simulation and retrospective reviews within your own program.

We discussed a few key concepts that should be considered as we move forward in pre-hospital airway management and overall care for acutely ill patients:

1. Patient positioning: ample evidence that patient’s should probably have some head elevation if possible during intubation (If you don’t believe me…check out this must read paper). This IS possible within the BK and it actually provided Karl with the best view when it was up near 40-45 degrees! Check out the following pics which demonstrates feasibility within the BK.

Patient is fully supine. Experts advocate "ear to sternal angle" but in our traditional position of supine you'll note that the ear is NOT at the sternal angle!

Patient is fully supine. Experts advocate “ear to sternal angle” but in our traditional position of supine you’ll note that the ear is NOT at the sternal angle!

And now, for a clear demonstration of “ear to sternal angle”. A position we should strive to do either to avert intubation or in preparation of an advanced airway.

A picture perfect view of the cords!

A picture perfect view of the cords! Patient at 40 degrees, and still able to intubate with a great view…even with the helmet on. Let’s integrate this!

2. Pack position: we decided that the airway/BMV pack would be removed from the Thomas pack and given to the intubating clinician immediately upon patient deterioration. This allowed the paramedic to have all necessary equipment for excellent airway management. The physician could then focus on drug administration and clinical decision making. We opened the Thomas pack fully beside the physician and placed the drug pack on the patient’s legs.

Note the drug pack on the patient's legs and the Thomas pack spread out to the right of the physician. This worked best in our setting.

Note the drug pack on the patient’s legs and the Thomas pack spread out to the right of the physician. This worked best in our setting.

Here’s what DIDN’T work.

This set up was very cumbersome if the drug pack is lying on a partially open Thomas pack. Another issue was the Thomas pack was still upright...and not lying flat.

This set up was very cumbersome if the drug pack is lying on a partially open Thomas pack. Another issue was the Thomas pack was still upright…and not lying flat. Also harder since we had to turn each time to get drugs rather than in front.

3. Apneic oxygenation: this is a bit trickier and something we’ll have to look at more closely to see what would be feasible since it will require 2 O2 sources. It was definitely challenging to get it set up when time constrained. (another must read paper on the value of apneic oxygenation).

Huge thanks to Karl for running through the sim case and providing value feedback on the ergonomics of the situation…what worked and what didn’t! We will all learn from this.

Helicopter cabin design for emergency medical services and interhospital transfer

AW169

AW169

ARHT is purchasing an AgustaWestland AW169, due for delivery in 2015. This provides an opportunity to to create a purpose-built interior that will best serve the helicopters mission profiles, and a considerable amount of planning is going into this.

This paper, published in Air Medical Journal 2012, details how specific cabin elements were designed and constructed for a German EC145 (the successor to the BK117 that the ARHT currently operates). Key to the design was a sliding module containing essential medical and monitoring equipment – the module can slide a considerable distance out the rear doors of the helicopter to aid the process of loading/unloading ventilated patients with lots of monitoring equipment in situ.

Full-text pdf of this article is available here (secure area limited to ADHB staff only – ADHB maintains an online subscription to this journal through the Philson Library at the University of Auckland School of Medicine)

Human factors in prehospital adverse events

defib

In the last decade or so, hospital medicine has learned (often the hard way) the importance of recognising the impact that human factors have when dealing with illness or emergencies.

While there is ample literature regarding the importance of human factors on the purely ‘aviation’ side of aeromedical work, there is little information about the importance (or otherwise) in the ‘medical’ side of prehospital care. The differences in environment, staffing, skill mix, time course of the patient, and a comparative paucity of resources means that extrapolating the ‘ED human factors‘ approach to the prehospital setting may not automatically be valid.

A study by the Ambulance Service of New South Wales, published in EMJ in 2012, sought to look at how human factors contributed to adverse events in the prehospital setting. The study involved surveying qualified and trainee paramedics regarding jobs they had been involved in where an adverse event or ‘near-miss’ occurred. Data was gathered for 370 jobs. On average, there were 10 contributing factors for each adverse event (range 5-15) – a typical ‘Swiss Cheese Model‘.

Factors which significantly increased the likelihood of an adverse event occurring were:

  • deteriorating patient (most important risk factor)
  • uncertainty about a change in patient condition
  • panic
  • on initial presentation patient seemed well
  • adaptation from low to high severity case
  • uncertainty in diagnosis
  • presence of reduced LOC
  • uncertainty in diagnosis

The presence of these factors, particularly grouped together, made adverse events or ‘near-misses’ more likely to occur.

(do these look familiar to anyone? I reckon most ED adverse events/near misses would have these factors as major contributors too!)

One of the most important points made in the discussion was

“The recognition of deteriorating and confounding patients, the management of uncertainty and decision making with impaired data may be considered as constructs of clinical judgement. If this conjecture is correct, then this study concurs with prior work that identified clinical judgement as the key issue in prehospital patient safety.”

The sequence of events that led to an adverse event or near miss was felt to be:

disconcerting patient factors –> uncertainty –> omissions –> patient harm

So how does this relate to our service?

  • factors contributing to adverse events or ‘near-misses’ in the prehospital setting are, according to this study, probably very similar to those that operate in our more familiar hospital setting. While we need to adapt to the prehospital environment, a new paradigm of thinking abut prehospital risk management to avoid error is probably NOT necessary.
  • assuming clinical judgement is a major issue in preventing prehospital adverse events, we should (in theory) be in a good position to counter this – our paramedic/doctor combination gives us clinical judgement from senior clinicians from two complementary backgrounds. Hopefully we have the best of both worlds.
  • Our model of care (doctor/paramedic/medically-trained crewman) puts us in a (relatively) well-resourced position to deal with deteriorating patients.
  • With ‘on initial presentation patient seemed well‘ being a risk for adverse events – we must keep in mind that complacency can be our enemy. With current dispatching protocols for our team, many of the jobs we do are based on geography rather than patient acuity, and many of the patients we transport are not actually that sick. Being lulled into a false sense of security and underestimating a patient’s illness/trajectory may be a significant risk for us.

Full text pdf for this post is available here (secure area limited to ADHB staff only – ADHB has online subscription access to this journal through the Philson Library at the University of Auckland School of Medicine)

Prehospital scene management

scene

As hospital doctors working in acute care, we have a considerable amount of control over the scene in which we work. Our ED resus bays have adequate space, lighting, and equipment (which is in the same place every time we need it). We have a huge number of team members we can draw upon for support in our patient care, and with prehospital notification of impending patient arrival we can assemble an appropriate team, set up relevant equipment ahead of time, and establish control over the scene before the patient arrives. We even have waiting areas for family and friends of critically ill patients and can delegate staff to look after them while a resuscitation is occurring.

In the prehospital setting, many of the factors above are unachievable, and to doctors this represents both a source of challenge and considerable discomfort.

One of the most interesting aspects of working as a doctor in the prehospital setting (both in practice and simulation) has been watching my paramedic colleagues in action at a prehospital scene – in particular the skill, calm, and aplomb with which they assess and manage a prehospital scene, and the adaptability with which this process occurs under highly variable circumstances.

While as HEMS doctors it would be uncommon for us to be in a position where we have a significant role in scene management – this role would usually be performed by ambulance staff already at the scene or by the helicopter paramedic – it is important for us to understand the process.

There is comparatively little literature available in this area. There are resources detailing ASSESSMENT of a scene, such as this chapter from the Prehospital Trauma Life Support manual.

With regards to MANAGEMENT of a prehospital scene, the authors of this study, published in EMJ in 2009, conducted interviews with experienced paramedics to generate a theory as to how paramedics manage a scene. The model that resulted was called “the space control theory of paramedic scene management”, which states that paramedics manage a scene by controlling the activities that occur in the space immediately around the patient “Space” is interpreted to include both physical and human (non-physical) elements.

“Although there are physical realities that present problems for scene management, for the most part the management of the scene involves how paramedics interact with other people. Indeed, it is through working with others that paramedics are able to solve the problems presented by both physical and human elements. This means that scene management is a dynamic social activity comprised of social processes.”

This figure from the paper provides overview of the theory:

space control theory

This model has multiple “human factors” elements – analogous to the increasingly recognised importance of human factors in hospital care.

Another useful resource for doctors at a prehospital scene is this 2007 slide set from Tony Smith – ADHB Intensivist, Medical Advisor to St John Ambulance, and Auckland HEMS doctor:

Slide1

Full-text pdf for this post is available here (secure area limited to ADHB staff only – ADHB has online subscription access to this journal through the Philson Library at the University of Auckland School of Medicine)

NAP4 and its implications for prehospital airway management

In 2011 the U.K. Royal College of Anaesthetists and The Difficult Airway Society released a report called NAP4 – the 4th national audit of major complications of airway management.

Full text of NAP4 report

Full text of NAP4 report

The report covered airway complications that occurred in anaesthesia, ICU, and ED settings (approximately 20000 in total). Every reported complication of airway management was analysed for causes and learning points.

The findings relating to ED complications have direct implications for prehospital airway management.

‘Take-home’ messages relating to ED airway management:

  • in the event of an airway complication (most commonly failed RSI), patients were more likely to die in ED or ICU than OR
  • at-risk patients were often not identified prior to the attempt at airway management
  • waveform quantitative capnography should be the standard of care for EVERY intubation
  • situations where the capnography reading was zero (indicating misplaced or completely obstructed ETT) were incorrectly attributed to cardiac arrest (CPR always generates SOME CO2)
  • complications arose when there was a ‘failure to plan for failure’
  • obesity was a major risk factor for airway complications

and, most importantly:

  • in the event of a surgical airway being needed, surgical cricothyroidotomy was almost universally successful, while needle cricothyroidotomy had a failure rate of up to 60%
  • the success of surgical cricothyroidotomy included those where ED doctors (not surgeons) were the ones performing the procedure

Here is an excellent podcast – it is an interview by Cliff Reid of Jonathan Benger, a Professor of Emergency Medicine and one of the authors of the NAP 4 study (sourced from emcrit.org) regarding the implications of NAP4 for emergency department airway management.

So what are the implications for our HEMS service?

The most relevant findings for us form NAP4 are the findings relating to airway complications in ED, more so than anaesthesia or ICU. Patients who we would intubate pre-hospital are those who, if prehospital intubation were not available, would be intubated shortly after arrival in ED. The majority of our doctors are ED-trained, and are most familiar with ED airway management (translation: simple, fast, relatively low-tech, with the fairly standardised approach for the majority of our patients)

Bringing ED airway management to the prehospital arena has its challenges. The patients are more undifferentiated, comparatively under-resuscitated, and there may not have been enough time to get a sense of their ‘trajectory’.Environmental  factors (light, weather, physical access to patient) will have a huge impact on the execution of airway intervention.  We have a lot less equipment – no Glidescope, less rescue devices, and no telephone to call for an anaesthetist and a tech with a trolley full of difficult airway equipment. We may have team members (relatively junior ambulance staff, for example) who have much less experience with RSI than ED nurses who are often part of our RSI team.

Doing the basics right therefore becomes even MORE important:

  • equipment must be effective, functional, and familiar to us through training
  • there must be a ‘shared mental model’ – including a plan for success and a plan for failure – which must be vocalised for every patient with all team members understanding their role
  • we must actively consider patient specific elements that will affect the plan for success and the plan for failure (anatomy, injury, obesity etc)
  • we must be as prepared as possible – if the situation allows, taking several extra minutes to optimise positioning, place nasal cannulae for apnoeic ventilation etc may be crucial
  • we can overcome the disorienting effect of unfamiliar/unfriendly environments by using our RSI checklist – this was we are unlikely to forget something crucial (like capnography)
  • there must be a relatively ‘hands off’ team member whose task is to maintain situational awareness – in particular to initiate the ‘plan for failure’ should it become necessary
  • in the event of ‘can’t intubate, can’t ventilate‘, a surgical cricothyroidotomy should probably be our ‘go-to’ surgical airway of choice. If needle cricothyroidotomy has a failure rate of up to 60% in a hospital setting, it is hard to imagine how it could fare better in the prehospital arena. Of course there may be exceptions to this (difficult neck anatomy etc)

More commentary on the results and implications of NAP4 can be found here (British Journal of Anaesthesia, section of report relevant to ED and ICU) and here (from Cliff Reid)

 

Ultrasound-assisted surgical airway

Ultrasound is routinely used in the ED setting to assist in performing procedures. With the ARHT’s recent purchase of a Sonosite Nanomaxx, we have the capability to take ultrasound guided procedures into the prehospital setting.

This paper from Academic Emergency Medicine, 2012, describes the use of ultrasound in emergency surgical cricothyroidotomy.

The technique is described and shown in a video podcast from ultrasoundpodcast.com. I highly recommend having a look round this site, there’s some great stuff there.

The video podcast is here

(Just in case anyone is wondering, I’m not advocating that we get scrubbed/gowned/masked for prehospital surgical airways!)

The cricothyroid membrane looks fairly straightforward to identify on ultrasound:

cricothyroid

In the setting of managing a difficult airway in the prehospital setting, specifically a predicted difficult RSI with your surgical kit out and ready to go should laryngoscopy/bougie fail, there may be a role for ultrasound.

Potential uses could scanning pre-RSI to check that the trachea is in the midline (especially if a patient has difficult-to-palpate neck anatomy), identifying the cricothyroid membrane and marking the area with a pen, or using real-time ultrasound guidance to make a cut or insert a needle (either for a Seldinger technique or just to act as a guide for your scalpel). Clearly this could add a few seconds to the procedure, but in the setting of a patient with difficult anatomy (obese, subcutaneous emphysema) could mean the difference between success and failure.

Thoughts?