Category Archives: Prehospital

Prehospital Lactate: Ready For Prime Time?

A few months ago, I started to notice a new piece of information coming across on my trauma activation pages: point of care lactate level. I had heard nothing about this prior to these pages, and was curious to know whether this was a new policy/practice, or some study that was in progress. So, of course, I had to do a little bit of reading to find out what was up with that. I’ll share that with you today.

Serum lactate has been used since forever in the inpatient setting, especially in the ICU. It is used as a surrogate for tissue hypoxia and/or metabolic acidosis. A number of studies have found that hypoperfusion is frequently underappreciated, since we tend to use crude vital signs (BP and pulse) which may look normal in early hypovolemia. Serum lactate guided therapy has been shown to improve survival in some studies, and can indicate that resuscitation is proceeding appropriately. Patients who do not show early improvement in their lactate levels are more likely to be refractory to resuscitation, and have higher mortality.

So it would make sense that if prehospital trauma professionals could identify occult tissue hypoperfusion in the field, appropriate resuscitation could start earlier. And nowadays, one can find a point of care device to measure just about anything. Thus, the extra tidbit of information on my trauma pages.

But remember, just because something makes sense doesn’t mean that it actually works. Thus, a group at the University of Birmingham (in the UK) did a systematic review of the literature through 2015, looking specifically at lactate levels obtained in the prehospital setting.

Here are the factoids:

  • Of the 2,415 articles screened, only 7 were suitable for analysis
  • These studies were judged to be of “low” or “very low” quality
  • The methods by which the lactate level were obtained (venous vs capillary), timing, and documentation were highly variable
  • The authors concluded that there is not yet enough data to support point of care lactate in the field

Bottom line: Point of care lactate drawn in the field would seem to be a good idea. Unfortunately, there aren’t any studies yet that are good enough to make this a standard practice. As with any new technique, if there’s no data then you MUST participate in a well designed study so it can be shown, yea or nay, that the practice is a good one. So join up!

Reference: Prehospital point-of-care lactate following trauma: a systematic review. J Trauma 81(4):748-755, 2016.

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EMS: How Soon To Extricate The Pinned Patient?

This post was requested by one of my EMS colleagues who is the medical director of a rural EMS agency.

Maybe you watched the movie “Signs” by M. Night Shyamalan, starring Mel Gibson.  Gibson is a preacher whose wife was killed in a tragic accident. She was running and was pinned against a tree by a pickup truck. She is so badly injured that only the pressure of the truck against her is keeping her alive (and together, apparently). Gibson gets to have a few final words before being extricated (and killed).

Could this really happen? Shouldn’t entrapped people be extricated immediately, or do our prehospital providers need to wait until more advanced medical care is present at the scene?

Here’s the movie clip, if you are interested:

Obviously, you will find NO research on anything like this. The real question is, should EMS first responders (if not medically equipped and able) completely extricate an entrapped patient before paramedics or other trauma professionals with advanced skills are present? In other words, can you die just from being unentangled from the wreckage, like Mel Gibson’s wife?

The answer is, possibly. But it might not be for the reasons you think. Remember, this is Hollywood.

There are two killers upon release from entrapment. First, the mechanism by which the patient is pinned may be holding pressure on things that are or want to bleed. These include the pelvic bones, injuries to the torso, groins, and proximal extremities, and possibly even intra-abdominal hemorrhage sources. I’m discounting the chest because if there is enough pressure to tamponade bleeding, it will probably critically impair hemodynamics and ventilation to the point of killing your patient prior to extrication anyway.

The second factor is a crush injury, with release of a bolus of acidic, potassium laden blood from the crushed extremity upon release. This is probably quite rare, since it takes a significant amount of time for the un- or under-perfused extremity to build up enough of these substances to pose a threat. If the patient has been entrapped for less than 30-60 minutes, there is probably little danger to releasing them.

Bottom line: It is probably best to wait for ALS providers to arrive so IVs can be established and post-extrication resuscitation can be planned. This includes having fluid and/or blood products available in case critical bleeding starts once the pressure has been released. And don’t worry about reperfusion injury unless your patient has been trapped for quite a while.

Related posts:

 

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Validation Of The Air Medical Prehospital Triage Score (AMPT)

Unneeded use of helicopter emergency medical services (HEMS) air transport is a problem around the world. This scarce and valuable resource tends to be over-utilized, resulting in unnecessary costs to patients and the health care system in general. Unfortunately, good and objective criteria for HEMS transport have been hard to come by.

A group at the University of Pittsburgh published a study earlier this year, developing an objective scoring system based on a huge dataset from the National Trauma Databank. They used a portion of the data to develop a model, and the remainder to test it. They developed the AMPT, which identified patients that showed a survival benefit with helicopter transport:

AAST2016-Oral23

For this AAST abstract,  they sought to validate the scoring system using an entirely different database, the Pennsylvania Trauma Systems Foundation registry. They used 14 years of data, and reviewed nearly a quarter million records. Once again, the authors were looking at in-hospital survival.

Here are the factoids:

  • 20% of patients were transported by air
  • But only 11% were predicted to benefit by using AMPT
  • For patients with an AMPT score < 2, transport by air did not increase survival
  • For patients who had an AMPT score >and were actually transported by air, survival was improved by 31% (!)

Bottom line: It looks like the AMPT score is a good predictor of improved survival for patients transported by air. But wait, it’s not that cut and dried. These statistics are based on populations; they cannot predict exactly which individual patient will benefit. What about those patients who actually died? Perhaps if they had gotten to the hospital a little faster, they would have done better? This is certainly a nice new tool to use in the decision-making process, but it can’t be the only one. 

References:

  • The air medical prehospital triage score: external validation supports ability to identify injured patients that would benefit from helicopter transport. AAST 2016, Paper #23.
  • Development and validation of the air medical prehospital triage score for helicopter transport of trauma patients. Ann Surg 264(2):378-385, 2016.
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Making The Trauma Team Time Out Even Better!

Over the past two days, I’ve discussed a method for optimizing the hand-off process between prehospital providers and the trauma team. Besides improving the quality and completeness of information exchange, it also fosters a good relationship between the two. All too often, the medics feel that “the trauma team is not listening to me” if the procedure is to move the patient onto the ED bed as quickly as possible.

And they are right! As soon as the patient hits the table, the trauma team starts doing what they do so well. It’s impossible for humans to multi-task, even though they think they can (look at texting and driving). We switch contexts with our brain, from looking at the patient to listening to EMS, back and forth. And it takes a few extra seconds to switch from one to the other. Team members will not be able to concentrate on the potentially important details that are being relayed.

What should you do if the team doesn’t want to wait?

First, educate them. Except for those who are in extremis or arrest, the patient can wait on the EMS stretcher for 30 seconds. Nothing harmful is going to happen in that short period.

Then, create a hard stop. The easiest way to do this is to place a laminated copy of the timeout procedure on the ED bed. And the rule is that the card doesn’t move until the timeout is done. This is very similar to what happens in the OR. The process should take only 30 seconds, then it’s over and the team can start.

Here’s a copy of a sample TTA Timeout card:

Download a TTA timeout card

Modify it to suit your hospital and process, and try it out!

Related posts:

Thanks to the trauma team at Ridgeview Hospital in Waconia MN for telling me about this cool trick!

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