Tag Archives: prehospital

Prehospital

Trauma Patient Mortality In ALS vs BLS Prehospital Transport

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There is a presumption that more education and attainment of more advanced skills lead to greater expertise in just about any field. The same argument holds true for prehospital provider training. Training to be an ALS provider (advanced EMT or paramedic) should add extra value in patient care over and above BLS training (emergency medical responder or EMT).

One way to measure that added value is by comparing trauma patient mortality across those levels of training. Paradoxically, many studies have shown either no benefit or an actual increase in mortality. How does this make sense? Some have speculated that the advanced training leads providers to “stay and play” and use the skills that they have learned. Other possibilities include study design issues (low subject numbers) or failure to consider some unknown variables that impact mortality.

A paper published just this month from Hennepin County Medical Center in Minneapolis examined this phenomenon more closely to determine whether this effect is real or whether other factors are involved. They performed a retrospective study of a nationwide database of prehospital ground transports, selecting records that involved only injured patients. Only patients with documented ALS or BLS providers who were transported to Level I or II trauma centers were included. The ratio of ALS to BLS transports was about 15:1, so propensity matching was performed to create equal groups for comparison.

Here are the factoids:

  • A total of 1,154 matched pairs were available for study,
  • Overall, mortality was significantly lower in the patient group transported by ALS providers
  • Mortality was also significantly lower in older patients (age > 50) and those with mechanisms other than falls
  • There was no statistical difference in patients with falls or in those with prolonged transport times

The authors concluded that more advanced prehospital training is associated with survival. They recognized that there are many factors in the care process that are not captured in the usual databases that may have an impact on survival.

Bottom line: This study was nicely designed and well-executed. It has the largest subject pool of any of the papers published on this topic. It shows that survival is higher when ALS providers transport the patient. But keep in mind that it does not show causality. We don’t know exactly why this is true. It could certainly be the advanced education, but there is still the possibility of other variables that we either haven’t thought of or are not captured in the available databases. But until we know better, we should encourage all EMS providers to up their game, and skill level! 

Reference: Emergency medical services level of training is associated with mortality in trauma patients: A combined prehospital and in-hospital database analysis. Journal of Trauma and Acute Care Surgery ():10.1097/TA.0000000000004540, January 9, 2025.

Prehospital

What Is The Safest Extrication Method From A Car Crash?

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Today’s post is directed to all those prehospital trauma professionals out there.

Car crashes account for a huge number of injuries worldwide. About 40% of people involved are trapped in the vehicle. And unfortunately, entrapped individuals are much more likely to die.

There are four basic groups (and their category in parentheses) of trapped car occupants:

  • those who can self-extricate or extricate with minimal assistance (self-extrication)
  • individuals who cannot self-extricate due to pain or their psychological response to the event but can extricate with assistance (assisted extrication)
  • people who are advised or choose not to self-extricate due to concern for exacerbating an injury, primarily spine (medically trapped)
  • those who are physically trapped by the wreckage who require disentanglement (disentanglement and rescue)

Prehospital providers have several choices to help extricate patients in the second and third categories: encourage self-extrication, rapid extrication without tools, or traditional extrication, where the vehicle is cut away to allow egress. The fourth category always requires tools for extrication.

Although rescue services try to minimize or mitigate unnecessary patient movement, stuff happens. Large and forceful movement is considered high risk, but smaller movements do occur. This is of particular concern in patients who might have a spine injury.

There have been several recent papers suggesting there might be greater benefits to self-extrication. A group of authors in the UK and South Africa designed a biomechanical study to test these extrication methods in healthy volunteers.

The authors wanted to determine exactly how much movement occurred using the various extrication techniques. The volunteers were fitted with an Inertial Measurement Unit, which measures the orientation of the head, neck, torso, and sacrum in real-time.  The IMU can detect even minimal changes in the orientation of the body. The volunteers were placed in a standard 5-door hatchback sedans that were prepared for each type of extrication, as seen above.

Here are the factoids:

  • A total of 230 extrications were performed for analysis
  • The smallest amount of maximal and total movement of body segments was seen in the self-extrication group
  • The greatest amount of movement was found in the rapid extrication group, with 4x to 5x the movement in the self-extrication group
  • The difference in body movement between the self-extrication group and all others was significant
  • In general, movement increased as extrication techniques progressed from roof removal to B post removal to rapid extrication

The authors concluded that self-extrication resulted in the smallest amount of movement and the fastest extrication time and should be the preferred technique.

Bottom line: This is the first study that specifically evaluated spinal movement occurring with commonly used extrication techniques. Other similar studies have used various measurement techniques, none of which are as precise as this. One potential weakness with this one is that it used healthy volunteers. But obviously, it is not practical to attempt anything like this with real, injured patients. 

Since we know that patients trapped in cars are more likely to die, time is of the essence. This study shows that self-extrication is both fast and safe with respect to spinal movement. The information will assist our prehospital colleagues in making the best decisions possible when faced with patients trapped in their cars.

Reference: Assessing spinal movement during four extrication methods: a biomechanical study using healthy volunteers. Scand J Trauma  open access 30: article 7, 2022.

General

Uber / Lyft For Medical Transport???

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In this day and age of ride-sharing apps like Uber and Lyft, it is possible to get a cheap ride virtually anywhere there is car service and a smartphone. And, of course, some people have used these services for transportation to the hospital instead of an ambulance ride. What might the impact of ride services on patient transport be for both patient and EMS?

Ambulance rides are expensive. Depending on region, they may range from $500-$5000. Although insurance may reduce out-of-pocket costs, it can still be costly. So what are the pros vs the cons of using Uber or Lyft for medical transport?

Pros:

  • Ride shares are inexpensive compared to an ambulance ride
  • They may arrive more quickly because they tend to circulate around an area, as opposed to using a fixed base
  • Riders may select their preferred hospital without being overridden by EMS (although it may be an incorrect choice)
  • May reduce EMS usage for low-acuity patients

Cons:

  • No professional medical care available during the ride
  • May end up being slower due to lack of lights and siren
  • Damage fees of $250+ for messing up the car

A fascinating paper suggests that ambulance service calls decreased by 7% after the introduction of UberX rides.  The authors mapped out areas where UberX rides were launching and examined emergency response data in these areas. They used a complex algorithm to examine trends over time in over 700 cities in the US and used several techniques to try to account for other factors. Here is a chart of the very fascinating results:

Bottom line: Uber and Lyft are just another version of the “arrival by private vehicle” paradigm. The use of these services relies on the customer/patient having very good judgment and insight into their medical conditions and care needs. And from personal experience, this is not always the case. I would not encourage the general public to use these services for medical transport, and neither do the companies themselves!

Reference: Did UberX Reduce Ambulance Volume? Health Econ 28(7)L817-829, 2019.

Abstracts, Prehospital

Best Of EAST 2023 #11: Prehospital Use Of TXA

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More stuff on TXA! I published two posts back in December on TXA hesitancy. This Friday, the trauma group at Wake Forest is presenting an abstract on TXA use by prehospital trauma professionals.

It is very likely that EMS carries tranexamic acid (TXA) in your area. Each agency has its own policy on when to administer, but the primary indication is hemorrhagic shock. A few ALS services may infuse for serious head injury as well.

The Wake Forest group was concerned that TXA administration might be occurring outside of the primary indication, hemorrhagic shock. They reviewed their experience using a six-year retrospective analysis of their trauma registry. The patients’ physiologic state before and after arrival at the hospital was assessed, as were the interventions performed in both settings.

Here are the factoids:

  • Of 1,089 patients delivered by 20 EMS agencies, one-third (406) had TXA initiated by EMS
  • Only 58% of patients who received prehospital TXA required transfusion after arrival
  • TXA administration based on BP criteria were as follows:
  • Similar compliance was noted when examining only high-volume EMS services

The authors concluded that TXA use is common in the prehospital setting but is being used outside of literature-driven indications.

Bottom line: This is an interesting snapshot of TXA use surrounding a single Level I trauma center. As such, it can’t be automatically applied to all. However, my own observations suggest that this drug is being used more liberally nationwide.

Clearly, the prehospital providers are starting TXA on patients who do not fit the category of severe hemorrhagic shock. Only 30% of patients receiving it had SBP < 90. Is this a bad thing? Referring back to my conversation on TXA hesitancy, I think not. But do keep in mind that giving any drug when not indicated adds no benefit and can certainly increase risk. The good news is that TXA is very benign when it comes to side effects.

However, policies are designed for a reason: safety. And if the EMS agency policy says to give TXA only for SBP < x, then that’s when it should be given. The prehospital PI process (or the trauma center’s) should identify variances and work to correct them. If EMS is “overusing” TXA in your area, your trauma center should add this as a new prehospital PI filter and let them know when it happens.

Here are my questions and comments for the presenter/authors:

  • Is using the need for transfusion a valid measure of the need for TXA? You found that half of the patients receiving TXA were not transfused. The decision to transfuse depends on surgeon preference, and they don’t always use objective criteria. And hey! Maybe the TXA worked, obviating the need for blood!

This is a straightforward and intriguing paper. I’m excited to hear more details on how you sliced and diced this data.

Reference: ARE DATA DRIVING OUR AMBULANCES? LIBERAL USE OF TRANEXAMIC ACID IN THE PREHOSPITAL SETTING. EAST 2023 Podium paper #34.

Complications, Prehospital

Scoop And Run VS Stay And Play: Part 5

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This is the last piece in my series on whether or not trauma patients should be initially managed with some limited interventions at the scene, vs just getting them into the ambulance and on their way to a trauma center. This article deals specifically with the needs of victims of penetrating trauma in big cities.

The Eastern Association for the Surgery of Trauma (EAST) published the results of a multicenter trial on the utility of prehospital procedures performed by EMTs and medics in this subset of patients. Most of the studies previously reviewed do not show an obvious advantage to dawdling at the scene.

The EAST study took an interesting approach. It limited patients to those in urban locations near trauma centers, which largely eliminated time from the equation. The authors could then attempt to identify any utility in performing procedures prior to trauma center arrival.

This was an observational trial of adults with penetrating injury to the torso or proximal extremity. A total of 25 trauma centers participated for a one-year period. Patients with penetrating injuries above the clavicles or in the distal extremities were excluded.

Here are the factoids:

  • Although 2,352 patients met inclusion criteria, a small number (68) were excluded because the method of transport was missing (!)
  • Type of transport was ALS (63%), private vehicle (17%), police (14%), and BLS (7%)
  • Nearly two-thirds (61%) received some type of prehospital procedure
  • The procedures performed included intubation (6% on scene, 2% in transport), IV access (49% on scene, 42% in transport), IO access (5% on scene, 3% in transport), fluid resuscitation (16% on scene, 32% in transport),application of a pressure dressing (23% on scene, 12% in transport), and tourniquet application (6% on scene, 2% in transport)
  • Patients who received prehospital interventions had significantly longer hospital length of stay (5.6 vs 4 days) and were more likely to develop ARDS, venous thromboembolisms, and urinary tract infections
  • In-hospital mortality was significantly higher in the intervention group (10.3% vs 7.8%)
  • Mortality significantly increased with the number of interventions performed at the scene and enroute to the trauma center
  • Prehospital intubation was strongly correlated with mortality, and the following procedures were also associated with higher mortality: fluid resuscitation, cervical spine immobilization, and pleural decompression
  • Prehospital IV insertion was significantly associated with survival, but tourniquet placement was neutral
  • There was no mortality difference based on the type of transport provided

Bottom line: This is a fascinating paper that applies to a limited subset of patients. Specifically, it only studied patients in urban areas with a trauma center that was presumably very close. Prehospital endotracheal intubation proved to be the most deadly intervention. A few studies have confirmed that intubation further degrades end-organ perfusion further in animals with severe hemorrhagic shock.

The finding that prehospital fluids were associated with higher mortality, but that IV access was not, is puzzling at first. However, there are a number of papers clearly showing that resuscitation without definitive hemorrhage control, can be deadly. This study confirms this fact in humans and lends support to the concept of permissive hypotension in these patients. 

Cervical spine immobilization proved to be a mortality risk. The reasons are not clear, but difficulties in placing an airway and increased intracranial pressure could be factors. The only clear indication would be for stabilization of the neck in patients with cervical cord injuries. However, in such cases the damage is done and collars are likely not of any benefit neurologically.

The biggest flaw in this study was that it did not record transport times. The authors assumed that times were short since the patients were injured in high density urban areas. There was also concern for selection bias, as more severely injured patients were more likely to undergo prehospital intervention.

The takeaway message is that in a setting with very short transport time to a trauma center, hemorrhage control trumps almost everything else. Obtaining IV access or applying a tourniquet may be beneficial, but should only occur once the patient is enroute to minimize time on scene. More advanced maneuvers such as fluid resuscitation, fluid resuscitation, collar placement, or needle decompression of the chest should be delayed for management by the trauma team.

These results cannot be generalized to patients with longer expected transport times, although we don’t have good research yet to back up this assertion. In those patients, it is probably best to adhere to the good old ABCs of ATLS. And of course, until this work is confirmed by more studies, do not go against any policies or procedures established by your prehospital agency!

Reference: An Eastern Association for the Surgery of Trauma multicenter trial examining prehospital procedures in penetrating trauma patients. J Trauma 91(1):130-140, 2021.