All posts by TheTraumaPro

Why I Don’t Write About Animal Studies

If you’ve been reading these posts for any length of time, you may have realized that I regularly write about new (or sometimes not so new) research studies that I believe have some impact on trauma professionals. But if you look closely, you’ll see that the vast majority are human studies. I can only recall 1 or 2 animal studies that I’ve commented on in the past 3+ years.

Why is that? Well, there are several reasons.

First, many of those papers describe low-level biomedical research that is tough for the average person to follow. They use sophisticated measurement and analysis techniques to pick apart a specific biological pathway or process. It almost takes a PhD to understand them.

Next, most of these studies are performing work that only incrementally increases our understanding of what’s going on at that microscopic level. These little bits of progress may ultimately add up to a major advance. But if I find it difficult to provide the big picture view of the importance of one of these minor findings to the average trauma professional, I’m not going to write about it.

Finally, and most importantly, many of these published results will not have any significance to our field. Some interesting, positive finding in an animal model may have been discovered. But why should we believe this will translate to something relevant to humans?

Look at the model of inflammation that’s been used to develop all manner of potential human drugs to block it in critically ill patients. To date, there have been nearly 150 such drugs developed and tested, at great expense. How many have actually worked and been approved for human use? Zero. Why? It turns out that the inflammation model used in mice creates a response that looks the same as what happens to humans. But it’s not. It turns out that completely different, parallel pathways have been studied. So the thousands of papers that picked apart these pathways used to treat mouse inflammation do not really apply to human medicine. Only to veterinary medicine. And mice veterinarians only!

Reference: Genomic responses in mouse models poorly mimic human inflammatory diseases. Proc Nat Acad Sciences, ePub Feb 11, 2013.

What To Do? Small Hospital, Unstable Patient

It’s the situation that physicians in smaller hospitals dread. A major trauma patient gets dropped off at the door. You do your evaluation, quickly determining that they need services that you don’t just have (head injury and positive FAST in the abdomen, let’s say). You call your community EMS service to transport to a Level I trauma center, which is about 30 minutes away by ground. And just as they are rolling out the door to the rig, the blood pressure drops to 60! What to do?!

The ATLS course is very clear, and very correct. Back into the ED for a quick re-evaluation. The most common cause for a significant disturbance in vitals or exam lies within the primary survey. You will almost always find a problem with Airway, Breathing, or Circulation. (A Disability problem can cause a problem on rare occasion (hypotension from impending herniation), but there’s not much that you can do about it, really. Hyperventilate, hyperosmolar therapy, okay but probably a poor outcome for the patient anyway.)

So you didn’t find any airway or breathing issue. But the abdominal stripe(s) you saw on FAST are larger, so it’s circulation. Now what? And does it matter if you have a surgeon available on call? The answer is simpler than you think.

ATLS says that, if you have surgical support available you have to use it in this type of situation. If you don’t have it, package the patient with a lot of blood and plasma and send. If you have a physician or nurse to spare you could consider sending them along to help during transport, but for small community hospitals this is not practical.

But if you do have a surgeon, does it make sense to use them? Not always! You must take into account response times and transport times. Let’s say it’s 2:00 am and you call your surgeon for this hypotensive patient. They may take up to 30 minutes to get in and see the patient. They then agree that the patient needs a laparotomy and she proceeds to call in the OR team. Yet another 30 minutes tick by.  Will the patient still even be alive when they roll into the OR?

Or you could just put the patient back in the ambulance (air preferably, but ground if you have to) and get them to your trauma center quickly. They can then be whisked directly into a waiting OR in less than 30 minutes from your door. This is probably the ideal solution here. Obviously this doesn’t work as well if you are a few hours away from your resource trauma center. 

Bottom line: Deciding what to do with a patient that needs urgent treatment that you can’t immediately deliver is tough! That’s why it’s always a calculus problem when you’re faced with this situation. But take all of the response and transport times into account, and do what’s best for your patient! 

Thanks to EM Res for posing this question!

EAST Starts Today!

The Eastern Association for the Surgery of Trauma opening session is in progress! I’ll be tweeting and blogging from the meeting through Friday, and I’ll be combing through some of the best papers in the blog next week. I’m on the lookout for groundbreaking work in areas that are practical or interesting to trauma professionals.

I’ll be tweeting live using the hashtag #east2014, so keep an eye out for the good stuff!

EAST 2014: CT Clearance of the Cervical Spine?

Cervical spine clearance has typically required us to address both bones and ligaments. For a long time, this has involved separate steps: imaging for the bones, and exam (or additional imaging) for the ligaments. But this extra step adds complexity and seems to have a low yield.

The number of studies supporting use of only CT to clear both bones and ligaments continues to increase. A poster being presented this week at EAST details the experience with this at Virginia Commonwealth University. They looked at all their blunt trauma patients over a 5 year period. They detailed all fractures, ligamentous injuries, and how they were discovered.

Here are the factoids:

  • A total of 5676 patients were entered in the study
  • 420 (7%) were diagnosed with cervical fracture
  • 53 (1%) had a ligamentous injury
  • Of the ligamentous injuries, 21 of 53 were suspected based on the CT. The remaining 32 all had fractures in addition to the ligamentous injury.

Bottom line: Yes, it’s small and retrospective, but it continues to paint the same picture as the other papers. The authors conclude that CT alone is sufficient to clear both bones and ligaments. I presume this excludes the group that can be cleared clinically. Adopting this process will streamline the clearance process, and help avoid complications like pressure sores. What about missed injuries? There will always be a few. We are currently at a point of diminishing returns in terms of how much diagnostic radiation, magnetism, and money we throw at this problem. But the key to successfully and safely implementing this is to make sure to have the most experienced clinicians reading the images.

Related posts

Reference: CT scan: it’s not just about the fracture. EAST 2014, poster #35.

 

EAST 2014: Reducing Trauma Repeat Imaging With A Cloud Service

Radiation exposure from diagnostic imaging remains of high interest to all trauma professionals and the lay public. A number of papers have already been written showing that repeat imaging in transferred patients is high due to issues with transmitting images between sending and receiving trauma centers. 

A variety of solutions exist for reducing this problem. One of the more technically oriented ones is LifeImage, a cloud based service. Images from just about any PACS system can be uploaded to the service by a referring hospital. The receiving center can peruse the images using a sophisticated browser based tool, or they can merge the PACS data for any or all studies into their own PACS system.

ShockTrauma in Baltimore receives severely injured patients for the entire state of Maryland. They reported their experience with this cloud service over a 6 month period, and compared it to 6 months before use during the prior year. Here are the factoids:

  • A total of 1,950 transfers were reviewed (!). Data was collected prospectively.
  • The number of patients undergoing repeat imaging decreased significantly, from 62% to 47%
  • Cost also decreased significantly, from $402K to $327K during the study periods
  • Hospital length of stay decreased from 4.4 to 3.8 days
  • There was no difference in mortality

Bottom line: Cloud solutions for transferring imaging information work! A lot of radiation and money was saved! Frankly, I’m puzzled as to why the decreases were so modest. I suspect that some or many of the potential referring hospitals were not participating at the time of the study. Nevertheless, it looks like the savings should easily pay for the cost of the service. I’ll definitely quiz the authors on this one and return with some answers.

Related posts:

Reference: Reduction in repeat imaging in patients transferred to a Level I urban trauma center decreases cost and radiation exposure. EAST 2014, poster #28.