Category Archives: Prehospital

Cool EMS Stuff: The Backboard Washer!

October 3, 2022 The Trauma Pro Leave a comment

Backboards are made to get messy. And every time your friendly EMS provider brings you a patient, they invariably have to swab it down to give the next patient a reasonably sanitary surface to lie on. But sometimes the boards get downright nasty and the cleanup job is a major production.

Enter… the backboard washer. I recently saw one of these for the first time at a Level III hospital in Ohio. Fascinating! Pop the board inside and seven minutes later it’s clean. And I mean really squeaky clean. You may think it looks clean and a good hand wash, but just take a look at the effluent water coming out of this washer!

These units use standard 100V 20A power and only require a hot water hookup and a drain. They can wash two boards at once.

Hospitals in the know need to locate one of these next to a work area for completing paperwork and some free food. What could be better?

Reference: Aqua Phase A-8000 spec sheet. Click to download.

Prehospital

Trauma Patient Transport By Police, Not EMS

August 9, 2022 The Trauma Pro Leave a comment

When I was at Penn 30+ years ago, I was fascinated to see that police officers were allowed to transport penetrating trauma patients to the hospital. They had no medical training and no specific equipment. They basically tossed the patient into the back seat, drove as fast as possible to a trauma center, and dropped them off. Then they (hopefully) hosed down the inside of the squad car.

Granted, it was fast. But did it benefit the patient? The trauma group at Penn decided to look at this to see if there was some benefit (survival) to this practice. They retrospectively looked at 5 years of data in the mid-2000’s, thus comparing the results of police transport with reasonably state of the art EMS transport.

They found over 2100 penetrating injury transports during this time frame (!), and roughly a quarter of those (27%) were transported by police. About 71% were gunshots vs 29% stabs.

Here are the factoids:

The police transported more badly injured patients (ISS=14) than EMS (ISS=10)
About 21% of police transports died, compared to 15% for EMS
But when mortality was corrected for the higher ISS transported by police, it was equivalent for the two modes of transport

Although they did not show a survival benefit to this practice, there was certainly no harm done. And in busy urban environments, such a policy could offload some of the workload from busy EMS services.

Bottom line: Certainly this is not a perfect paper. But it does add more fuel to the “stay and play” vs “scoop and run” debate. It seems to lend credence to the concept that, in the field, less is better in penetrating trauma. What really saves these patients is definitive control of bleeding, which neither police nor paramedics can provide. Therefore, whoever gets the patient to the trauma center in the least time wins. And so does the patient.

Related posts:

Reference: Injury-adjusted mortality of patients transported by police following penetrating trauma. Acad Emerg Med 18(1):32-37, 2011.

Prehospital

What Is The Safest Extrication Method From A Car Crash?

March 3, 2022 The Trauma Pro Leave a comment

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

Car crashes account for a huge number of injuries world-wide. About 40% of people involved in them are initially 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 the use of 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 movement of the patient, stuff happens. Large and forceful movement is considered high risk, but smaller movement do occur. This is of particular concern in patients who might have a spine injury.

There have been a number of 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 methods of extrication in healthy volunteers.

The authors wanted to find out 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 very small changes in 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 that it 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 a variety of 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 car.

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

Prehospital, Resuscitation

Best Of EAST #16: More On TXA

January 7, 2022 The Trauma Pro Leave a comment

Here’s another abstract dealing with TXA. But this one deals with the classic CRASH-2 use for patients with major bleeding. The original patient showed that TXA improves survival if given within 3 hours of injury. More and more prehospital units (particularly aeromedical services) have been administering TXA enroute to the trauma center to ensure that this drug is given as early as possible.

Many of these same services carry packed cells (or in rare cases, whole blood) so that proper resuscitation can be started while enroute as well. A multicenter group led by the University of Pittsburgh evaluated the utility of giving both TXA and blood during prehospital transport.

Their study summarizes some of the results of the Study of Tranexamic Acid During Air and Ground Medical Prehospital Transport Trial (STAAMP Trial). This study ran from 2015 to 2019 and randomized patients to receive either TXA or placebo during air or ground transport to a trauma center. It included blunt or penetrating patients at risk for hemorrhage within 2 hours of injury who were either hypotensive or tachycardic. Outcome measures included 30-day mortality, 24-hour mortality, and a host of complications.

This abstract outlines a secondary analysis that retrospectively reviewed the impact of using prehospital packed red cells (pRBC) in addition to the TXA/placebo during transport.

Here are the factoids:

There were 763 patients in total, broken down as follows
- TXA only – 350
- pRBC only – 35
- TXA + pRBC – 22
- Neither – 356
Patients who received blood with or without TXA were more severely injured with ISS 22 vs 10-12 in the non-pRBC groups
Mortality was higher in the pRBC (23%) and TXA+pRBC groups (29%)
TXA alone did not decrease mortality
TXA + pRBC resulted in a 46% reduction in 30-day mortality but not at 24 hours
packed cells alone decreased 24-hour mortality by 47%

The authors concluded basically what was stated in the results: short term mortality was decreased by pRBC alone, and 30-day mortality with TXA + pRBC. They recommended further work to elucidate the mechanisms involved.

Bottom line: This abstract may also suffer from the “low numbers” syndrome I’ve written about so many times before. The conclusions are based on two small groups that make up only 7% of the entire study group. And these are the two groups with more than double the ISS of the rest of the patients. The authors used some sophisticated statistics to test their hypotheses, and they will need to explain how and why they are appropriate for this analysis. Nevertheless, the mortalities in the blood groups number only in the single digits, so I worry about these statistics.

Here are my questions for the authors and presenter:

How do you reconcile the significantly higher ISS in the two (very small) groups who got blood? How might this skew your conclusions regarding mortality? Couldn’t the TXA just be superfluous?
How confident are you with the statistical analysis? Could the results be a sampling error given that red cells were given to only 7% of the overall study group?
I am having a difficult time understanding the conclusion that mortality was reduced in the blood groups. Specifically, it is stated that 24-hour mortality is reduced by 47% in the blood-only group. But the mortality is 14% (5 patients)! Reduced 47% from what? I don’t see any other numbers to compare with in the table. Confusing!

Obviously, there must be more information that was not listed in the abstract. Can’t wait to see it!

Reference: PREHOSPITAL SYNERGY: TRANEXAMIC ACID AND BLOOD TRANSFUSION IN PATIENTS AT RISK FOR HEMORRHAGE. EAST 35th ASA, oral abstract #39.

Head, Prehospital

Hitting The Brakes May Increase Intracranial Pressure During The Ambulance Ride!

October 8, 2021 The Trauma Pro Leave a comment

One of the most common injuries encountered by trauma professionals is blunt head trauma, and it’s one of the leading causes of death in young people. Keeping the level of intracranial pressure (ICP) within a specified range is one of the basic tenets of critical neurotrauma care in these patients. Most trauma centers have sophisticated algorithms that provide treatment guidance for various levels of ICP or cerebral perfusion.

The vast majority of patients with severe head injuries are transported to the hospital in some type of ambulance. Obviously, the exact ICP level is not known during transport because no monitoring device is present. We can sometimes infer that ICP is elevated if the patient has a Cushing response (wide pulse pressure and bradycardia) or unequal pupils. But for the most part, we assume that ICP is in a steady state during the ambulance ride.

But here’s something I never considered before: can ambulance acceleration or deceleration change the ICP through shifting of the brain or cerebrospinal fluid?

Patients are generally loaded into ambulances head-first, with their feet toward the back door. Frequently, they must be positioned supine in consideration of possible thoracic or lumbar spine injury. This position itself may lead to an increase in ICP. But what happens when the ambulance is hitting the brakes as it approaches a light or stop sign? As the patient’s weight shifts toward the top of the head, so does the CSF, spinal cord, and brain. Couldn’t this, too, increase ICP?

The anesthesiology group at the Erasmus Medical Center in Rotterdam, Holland performed a very novel study to assess this very thing. They recruited twenty participants in whom they evaluated ICP in various positions during acceleration and deceleration.
No, the subjects did not have an actual invasive ICP monitor inserted.

The authors used a novel way to infer pressures: optic nerve sheath diameter (ONSD). The optic nerves are direct extensions of the brain, and CSF travels freely in the nerve sheath. As ICP rises, the diameter of the nerve sheath increases. The subjects were fitted with a special helmet with two devices mounted on it. The first was a 7.5 Mhz ultra-sound probe focused on the back of the eye. The second was an arm with an orange dot on the end. This was adjusted so that the ultrasound probe was pointing at the optic nerve sheath when the other eye was focused on the dot. Subjects just watched the dot and measurements streamed in! Crude but very effective.

Baseline measurements were taken without acceleration or deceleration, then repeated when accelerating to 50 km/hr and decelerating to a stop.

Here are the factoids:

A total of 20 subjects were tested, and their oxygen saturation, blood pressure, and pulse were identical pre- and post-test
Baseline ONSD was about 5mm; a relevant change in diameter was determined to be more than 0.2 mm
Lying supine, the ONSD in nearly all subjects increased from an average 4.8 to 6.0 mm during deceleration
With the head raised to 30º, most values remained steady (from 4.8 to 4.9 mm) during deceleration

The left block shows the increase in size of the optic disk with braking while supine. The right one demonstrates that this effect is neutralized by elevating the head 30º.

Bottom line: This is a small, simple, and creative study, yet the results are very interesting! It is clear that optic nerve sheath diameter increases significantly during deceleration in patients who are supine. And this effect is eliminated if the head of bed is elevated 30º.

Unfortunately, we have no idea how the change in ONSD corresponds to absolute values of, or relative increases in, ICP. Does a change of 1.2mm indicate a 5 torr increase in ICP? A 5% increase? Is it proportional to the absolute ICP? We just don’t know.

But the data is clear that a measurable change does occur. Until better data is available, it may be desirable to transport patients with serious head injuries with the head elevated to 30º if there are no concerns for lower spine injury. Or failing that, make sure the driver does not have a lead foot!

Reference: Ambulance deceleration causes increased intra cranial pressure in supine position: a prospective observational prove of principle study. Scand J Trauma Open Access 29:87, 2021.

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