If you have a BVM (Bag Valve Mask resuscitator), you should not need naloxone. The problem is inadequate respiration, not inadequate naloxonation.

- Rogue Medic

EMS Time and Survival from Blunt and Penetrating Trauma

ResearchBlogging.org
 

People will tell you that they just know that we need to load and go. Some even claim that the mythological Golden Hour is real. Maybe there will be an episode of Ancient Aliens about R Adams Cowley identifying the meaning of trauma and writing it on a cocktail napkin in a bar.
 

Debate continues over the “load and go” versus “stay and stabilize” approach to patient care in the out-of-hospital setting because there is a paucity of supportive data for either argument.[1]

 

All trauma alerts and patients who were not trauma alerts, but were later admitted to the trauma service of a level 1 trauma center from 1996 to 2009 were included.
 

Exclusion criteria were extrication, missing or erroneous out-of-hospital times, intervals exceeding 5 hours, missing data, and nonblunt or penetrating injury (ie, burns, drowning, hangings).[1]

 

One odd aspect of the data is that they do not record the response times, so the out-of-hospital times do not include response times.
 

we contacted the county EMS agency to obtain general descriptive information on county response times. For basic life support response, the median 90th percentile for system standard response times is 6 minutes 15 seconds (range 4 to 8 minutes). For advanced life support response, the median 90th percentile for system standard response times is 6 minutes 5 seconds (range 4 minutes 28 seconds to 7 minutes 45 seconds).[1]

 

The response times seem to have pretty good consistency, so maybe that does not affect outcomes. Still, the out of hospital time period does need to have response time added.
 

We categorized out-of-hospital times into 10-minute intervals a priori with the intent of choosing an interval that is operationally practical, clinically feasible, and politically acceptable.[1]

 

 

It is interesting that the mortality rate increases until about 22 minutes of scene time, then mortality improves. This could just be a factor of the small numbers with scene times that long.

For blunt trauma, almost the opposite pattern exists. Fans of immobilization might see this as some kind of evidence that back boards save lives. Maybe immobilization kills any benefit to short scene times, but shorter scene times do seem to increase mortality.

There may be a Diamond Scene Time of 5 minutes for penetrating trauma. Between the ≈2 minute scene time and the ≈7 minute scene time the mortality rate jumps dramatically, but this may also just be a function of small numbers.

How much time is appropriate/necessary for penetrating trauma?

Even PHTLS (PreHospital Trauma Life Support) guidelines tell us that there is no reason to worry about “spinal immobilization” for penetrating trauma, unless there is some noticeable neurological deficit.[2] No worries about distracting injuries with penetrating trauma. There probably still is not any benefit to immobilizing these patients.

Therefore, for trauma patients with serious injuries, the most important parts of scene time are the time taking the stretcher (without the spinal implements of destruction) to the patient, a rapid assessment, plugging the holes and managing airway while moving the patient to the stretcher, then moving the stretcher to the ambulance.

Not much time needed.
 

 

There is a very clear connection between severity of injury and survival.
 

The odds of mortality with patients having an Injury Severity Score greater than 15 was 91.06 compared with those with less than 15 (95% CI 70.07 to 118.34) (Figure 6).[1]

 

An OR (Odds Ratio) of 90 is huge.
 

The association between increased out-of-hospital times and decreased mortality may be in part explained by EMS providers moving with haste for patients thought to have serious injury and taking more time for patients recognized as having minor injuries.[1]

 

With penetrating trauma, there may be less of an effect, but it should not produce opposite outcomes.
 

Our study did not find an association between transport times and mortality.[1]

 

Even further suggestion that we fly far too many patients for no apparent benefit.

The authors suggest that this might reflect the benefit of driving past a non-trauma hospital to arrive at a trauma center.

Almost all of the patients had scene times in the 0-9 minute and 10-19 minute groups and transport times in the same groups. The scene times produced statistically significant differences with distributions similar to the distributions of the transport times.

Is the transport time less important?

Does more time on scene really improve survival for blunt trauma patients?

 

Also see –

Is the Golden Hour Full of Crap?

And my correction of my too simple look at the data and graphs from this study –

Is the Difference in Penetrating Trauma Mortality Truly Significant? Part I

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Footnotes:

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[1] Emergency Medical Services Out-of-Hospital Scene and Transport Times and Their Association With Mortality in Trauma Patients Presenting to an Urban Level I Trauma Center.
McCoy CE, Menchine M, Sampson S, Anderson C, Kahn C.
Ann Emerg Med. 2013 Feb;61(2):167-74. doi: 10.1016/j.annemergmed.2012.08.026. Epub 2012 Nov 9.
PMID: 23142007 [PubMed - in process]

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[2] Spine Immobilization Following Penetrating Trauma
PHTLS podcast
PHTLS (Prehospital Trauma Life Support)

http://www.phtls.org

1/18/2010 12:00 PM
Podcast page

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McCoy CE, Menchine M, Sampson S, Anderson C, & Kahn C (2013). Emergency Medical Services Out-of-Hospital Scene and Transport Times and Their Association With Mortality in Trauma Patients Presenting to an Urban Level I Trauma Center. Annals of emergency medicine, 61 (2), 167-74 PMID: 23142007

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Comments

  1. Great post i like it useful information about Blunt and Penetrating Trauma i love it keep up your good work doing dissertation spss help

  2. I find it interesting (good) that they actually published those graphs. I’m not sure what you can really say based on the graphs, as the error bars are way too wide to make good conclusions. For instance, there is no real difference in death rate due to scene time on penetrating injuries that can be determined by this study based on Figure 5.

    My impression (from the graphs) is that any data driven decisions probably are not being done well if this is typical. For instance, it appears that a severity score of between 15 and 30 could be equivalent to one of 75 for penetrating wounds. That indicates a real problem with the measurement and or measurer. Unless the goal is to tell the difference between a minor wound and one that is not. And in that case, do you really need a 75 point scale?

  3. Yeah, I was also interested in those graphs as MV noted. I always tend to view graphs with a grain of salt. With graphs, its very easy to skew data. And then of course, we aren’t even talking about how accurate the collected data is. Regardless, very interesting article.

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