Category Archives: Thorax

What’s The Best Chest Seal For Sucking Chest Wounds?

June 22, 2017 The Trauma Pro 1 Comment

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.

Procedures, Thorax

Long-Term Experience With Endovascular Aortic Repair For Trauma

May 5, 2017 The Trauma Pro Leave a comment

For decades, the treatment of blunt injury to the thoracic aorta was open repair. The big debate at the time was use of cardiac bypass vs fast clamp and sew. But starting in 1997 with the introduction of thoracic endovascular aortic repair (TEVAR) of this injury, we have rapidly moved to the point where most traumatic aortic injuries are repaired using this technique.

A report that was written nearly a decade ago indicated a relatively high complication rate for the procedure. Graft complications were reported in 18% of patients, with 14% showing endoleaks. Stroke and left arm ischemia were also reported.

The diagram above shows insertion for management of an aneurysm, but the technique is similar for trauma. Blunt aortic injury occurs closer to the left subclavian artery and care must be taken to place the endograft closer to but not covering its orifice.

As the insertion systems and stents improved, short term events have been on the decline. Unfortunately, long term followup data has been hard to come by.

Until now. An article that is not yet in print reports 11 years of experience and followup with patient undergoing TEVAR at the ShockTrauma center in Baltimore.

Here are the factoids:

88 patients underwent TEVAR during the study period, all from blunt trauma
Average ISS was 38, showing these patients were severely injured
Overall mortality was 7%, but none was due to the TEVAR procedure
TEVAR-related complication rate was 9% Endoleaks at the ends of the graft occurred in 4 patients, and all required repair. There were 4 other minor leaks that resolved on their own.
26 had all or part of the left subclavian orifice covered at initial operation. None developed ischemia, although 2 had a prophylactic carotid-subclavian bypass before TEVAR.
The longest followup imaging occurred 8 years after the procedure. No long-term complications were noted.

Bottom line: TEVAR has essentially replaced open repair of the aorta, except in special cases. We continue to learn from our experience, and the complication rate is still falling. Other than endoleaks recognized in the postop period, most other complications rarely occur. Long term followup is poor, but in the patients who do return, there were no complications. But remember, this is an expected sampling bias. If the patient had major problems and/or died, they would just be lost to followup. We would never know.

Thorax

What’s Wrong With My Patient? Final Answer!

May 1, 2017 The Trauma Pro Leave a comment

I previously described a young man who was recovering from surgery for repair of a stab to the heart. He presented shortly after discharge with fever, a slightly elevated WBC, some EKG changes, and a small pericardial effusion.

Several people tweeted out the answer, which is post-pericardiotomy syndrome (PPS).

PPS is an inflammatory reaction to traumatic and then surgical injury to the pericardium. It is seen in a relatively small percentage of patients who undergo pericardiotomy for trauma, which is why patients who develop it are such a surprise to trauma professionals. A similar condition can develop after myocardial infarction (Dressler syndrome) and was first described in 1956. The classic paper describing PPS after trauma was published five years later (cited below).

Symptoms typically develop 1-6 weeks after surgery, and usually consist of low grade fevers, malaise, chest pain, and occasionally arthralgia. A pericardial friction rub may be present (and where is that stethoscope, BTW?). The WBC is usually elevated, with some degree of left shift. EKG may show some degree of pericarditis, including global ST elevation and T wave inversion.

Chest x-ray is usually nonspecific, but may show pleural effusion or an enlarged heart due to the presence of some pericardial fluid. Ultrasound may confirm a pericardial effusion, but this is not a reliable finding since the pericardium is typically left open at the end of the operation.

Treatment is symptomatic, usually consisting of NSAIDS or aspirin to tone down the inflammatory response. These drugs are usually given for 4-6 weeks, then tapered. If the effusion is large, pericardiocentesis may be needed.

Bottom line: If your postop heart injury patient presents with these symptoms, consider infectious etiologies first, but remember that they are typically even less common than post-pericardiotomy syndrome. Reassure your patient, then reach for the ibuprofen to get them through it.

Reference: Postpericardiotomy syndrome following traumatic hemopericardium. Am J Cardiology 7(1):83-96, 1961.

Thorax

What’s Wrong With My Patient? Part 2

April 28, 2017 The Trauma Pro 1 Comment

In my previous post, I described a young man who had recovered from a stab to the heart. He did well for a week and a half, but then presented to the ED with significant chest pain. It seems to be substernal and somewhat pleuritic. What should you do to work it up further?

There have been a number of helpful comments. The first order of business is to rule out problems which may prove to be life threatening. In his case, ischemic disease and some failure of the repair must be ruled out quickly. Although ischemia or MI are unlikely in this young man, they are possible and should be evaluated.

I recommend the following:

Auscultate the chest and heart (remember this from medical school?)
PA chest x-ray
EKG
CBC
Troponin
FAST exam focusing on the heart

My list is short and simple, and should help me figure out nearly all significant problems.

In this case, the following findings are present:

The lungs are clear, and their is a faint cardiac friction rub
The chest x-ray is unremarkable
EKG shows ST elevations in two of the lateral leads only. Otherwise, it is normal.
CBC is normal with the exception of WBC 14,000
There is a trace level of troponin present
FAST demonstrates a very small pericardial effusion without clot

So what do you make of all this? What’s the diagnosis? What do you need to do? Tweets and comments please.

Answers Monday!

Thorax

What’s Wrong With My Patient?

April 27, 2017 The Trauma Pro Leave a comment

I’ve had several requests for this case recently, so I figured I’d put it out there again.

A 25 year old man is involved in some sort of violent, non-productive interpersonal relationship. He sustains a stab to the left chest, and is brought to your trauma center as a trauma team activation. During the FAST exam, a moderate effusion with visible clot is seen in the pericardium.

Appropriately, you run to the OR and prepare for a left thoracotomy. You perform a pledgeted repair of the ventricle (black arrow) and close.

The patient does well and is discharged home five days later. He returns to your clinic the following week and is doing well. You remove the staples.

One week later, he returns to your emergency department complaining of significant chest pain. He describes it as deep, behind his sternum, and it seems to be exacerbated by breathing.

Now what? What are you thinking about? What additional exam do you need. What labs?

Tweet or comment with your answers and suggestions. More on this tomorrow!

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