The treatment of a “sucking chest wound” in the field has typically been with application of some type of occlusive dressing. Many times, a generic adhesive dressing is applied, typically the same kind used to cover IV sites. This is quick, easy, cheap, and readily available in the ambulance. But there is a danger that this could result in development of tension pneumothorax, because the dressing not only keeps air from getting in but also keeps any buildup of pneumothorax from getting out.
To avoid this, a number of vented products have been developed and approved by the US Food and Drug Administration (FDA). These devices have some sort of system to allow drainage of accumulating air or blood, typically a one-way valve or drainage channels. They also need to stick well to a chest wall, which may have blood or other fluids that might disrupt the seal completely.
The US Army has a strong interest in making sure the products they use for this purpose work exactly as promised. The US Army Institute of Surgical Research examined 5 currently FDA-approved products to determine their ability to adhere to bleeding chest wounds, and to drain accumulating air and/or blood from the pleural space. They developed an open chest wound with active bleeding in a swine model.
An open hemopneumothorax was created by infusing air and blood, the animal was stabilized, then additional aliquots of air and blood were infused to simulate ongoing bleeding and air buildup. The image below shows the 5 products used and the animal setup:
Here are the factoids:
- Creation of the open hemopneumothorax caused the intrapleural pressure to move toward atmospheric pressure as expected, resulting in labored breathing and reduced O2 saturation
- Sealing the wound with any of the chest seal products corrected all of the problems just noted
- Chest seals with one way valves did not evacuate blood efficiently (Bolin and SAM). The dressings either detached due to pooled blood, or the vent system clogged from blood clot.
- Seals with laminar channels for drainage (see the pig picture above) allowed easy escape of blood and air
- Success rates were 100% for Sentinel and Russell, 67% for HyFin, 25% for SAM, and 0% for Bolin
Bottom line: Prehospital providers need to be familiar with the products they use to cover open chest wounds. Totally occlusive dressings can result in development of a tension pneumothorax if there is an ongoing air leak from the lung. Vented chest seals are preferable for these injuries. Just be aware that vented seals with drainage channels perform much better than those that rely on a one-way valve.
Reference: Do vented chest seals differ in efficacy? An experimental
evaluation using a swine hemopneumothorax model. J Trauma 83(1):182-189, 2017.
Delayed diagnoses / missed injuries are with us to stay. The typical trauma activation is a fast-paced process, with lots of things going on at once. Trauma professionals are very good about doing a thorough exam and selecting pertinent diagnostic tests to seek out the obvious and not so obvious injuries.
But we will always miss a few. The incidence varies from 1% to about 40%, depending on who your read. Most of the time, they are subtle and have little clinical impact. But some are not so subtle, and some of the rare ones can be life-threatening.
The trauma tertiary survey has been around for at least 30 years, and is executed a little differently everywhere you go. But the concept is the same. Do another exam and check all the diagnostic tests after 24 to 48 hours to make sure you are not missing the obvious.
Does it actually work? There have been a few studies over the years that have tried to find the answer. A paper was published that used meta-analysis to figure this out. The authors defined two types of missed injury:
- Type I – an injury that was missed during the initial evaluation but was detected by the tertiary survey.
- Type II – an injury missed by both the initial exam and the tertiary survey
Here are the factoids:
- Only 10 observational studies were identified, and only 3 were suitable for meta-analysis
- The average Type I missed injury rate was 4.3%. The number tended to be lower in large studies and higher in small studies.
- Only 1 study looked at the Type II missed injury rate – 1.5%
- Three studies looked at the change in missed injury rates before and after implementation of a tertiary survey process. Type I increased from 3% to 7%, and Type II decreased from 2.4% to 1.5%, both highly significant.
- 10% to 30% of missed injuries were significant enough to require operative management
Bottom line: In the complex dance of a trauma activation, injuries will be missed. The good news is that the tertiary survey does work at picking up many, but not all, of the “occult” injuries. And with proper attention to your patient, nearly all will be found by the time of discharge. Develop your process, adopt a form, and crush missed injuries!
Reference: The effect of tertiary surveys on missed injuries in trauma: a systematic review. Scand J Trauma Resusc Emerg Med 20:77, 2012.
A couple of years ago I wrote about a paper that examined patterns in delayed diagnoses in injured children. It was a single-hospital study of children treated at a Level II pediatric trauma center. In that study, the overall rate of delayed diagnosis was 4%. The orthopedic component looked high but was not really broken down in detail.
A soon-to-be-published study looked at more recent experience with this issue, specifically in pediatric patients with orthopedic injury. They specifically evaluated all pediatric patients with bone, joint, peripheral nerve, and tendon injuries treated at their Level I pediatric trauma center over a nearly 6 year period. Orthopedic surgery consults were obtained at the discretion of the trauma or primary service.
How good was their discretion? Here are the factoids:
- 1009 trauma activations were reviewed, of which 196 (19%) were eventually diagnosed with an orthopedic injury
- There were 18 children (9%) with a delayed diagnosis, defined as one discovered 12 hours or longer after admission. Most were missed on initial exam or imaging
- The injuries were literally all over the place. There was no obvious pattern.
- Six of these were detected on tertiary survey
- Average time to discovery was 3 days, and the average age of these children was 11 years
- Children with a delayed diagnosis tended to be much more seriously hurt (ISS 21 vs 9), and more likely to have a significant head injury (GCS 12 vs 14)
- One child required surgery for the delayed diagnosis, the rest were managed with splinting/casting or observation
Bottom line: Delayed diagnoses happen in children, too. And typically, they are due to a failure in the physical exam. Sometimes there is nothing to discover on the exam. But often times, if the mechanism is fully taken into account and a really good exam is performed, these injuries may be found early.
I don’t consider an injury found on tertiary exam to be a delayed diagnosis, as long as it is performed within a reasonable time frame (24-48 hours max). It’s a well established fact that some injuries will not manifest as pain or bruising until the next day, or longer. So pick a maximum time interval (but don’t make it too early either) and do a tertiary survey on all children who are trauma activations, have multiple injuries, or have a significant mechanism.
Reference: Incidence of delayed diagnosis of orthopaedic injury in pediatric trauma patients. J Ortho Trauma epub ahead of print, April 29, 2017.
This month’s newsletter is dedicated to those hospitals that transfer trauma patients to higher level trauma centers. And there are lots of you out there. I’ve included some information to help with the decision making in that process. Here are the topics covered:
- Impact of the Rural Trauma Team Development Course on trauma transfers
- The real truth about imaging prior to transfer
- Image sharing systems
- Secondary overtriage: what it is and why it’s bad
- A sample checklist to make sure all the important stuff is done prior to transfer
I’ve also included a link to a Word document version of the checklist so you can download and customize it to suit your hospital’s needs.
The next newsletter will be released over the July 4 weekend. It will cover the other end of the transfer: the receiving hospital.
All of my subscribers received this newsletter at the beginning of the month. Subscribe now and be sure to get the next issue early, too. So sign up for early delivery now by clicking here!
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Two days ago, I discussed getting the traditional chest x-ray routinely after chest tube insertion. The answer was yes, it is important even if it appears to be functioning correctly. But yesterday, I also showed you how the chest x-ray can lie.
Remember this image?
Looks perfect! But it’s a 2-D view and you don’t know where the tube is in the anterior-posterior axis. It turns out to be in the patient’s subcutaneous tissues of his back, near his scapula!
So what if this is a trauma activation patient and you are getting ready to send your patient for a chest CT shortly? Should you follow the usual dogma and still get a conventional chest x-ray prior to leaving the trauma bay?
The answer is no! Typically, your trauma activation patient should have rapid access to the CT scanner, so you won’t have to wait very long. And the additional 3-D information is very helpful in making sure the tube is placed exactly where you want it.
Bottom line: If you are planning on obtaining a chest CT anyway in your trauma patient, don’t bother with a conventional chest x-ray first to check chest tube position. But DON’T order a chest CT for this reason alone! Remember, the chest CT is only for detecting aortic injury in blunt trauma. It should not be used for diagnosing fractures, hemothorax, or pneumothorax. Or chest tube position!