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

April 4, 2023 The Trauma Pro Leave a 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.

Complications

NSAIDs And Fracture Healing Revisited – Yet Again!

March 29, 2023 The Trauma Pro Leave a comment

I’ve written so many posts about the use of non-steroidal anti-inflammatory drugs (NSAIDs) it’s practically getting old. To summarize, some old animal studies suggested that using NSAIDs during fracture healing could impair the process. However, human studies were not so convincing.

Over the years, there has been quite a bit of conflicting evidence. This generally means the association between healing and NSAID use is weak. However, after this period of time, we should have become aware of a significant cause/effect relationship.

The Eastern Association for the Surgery of Trauma recently released a practice management guideline regarding the use of NSAIDs for the treatment of acute pain after orthopedic trauma. They used a standard methodology to identify and analyze published research. They focused on human studies specifically relating to this drug class’s use in fractures. The group ultimately identified 19 pertinent research papers for analysis, 10 of which were prospective, randomized studies.

Here are the three questions they asked, with their answers:

Should NSAIDs be used in analgesic regimens for adult patients
(≥18 years old) with traumatic fracture versus routine analgesic
regimens that do not include NSAIDs to improve analgesia and
reduce opioid use without increases in non-union and acute kidney
injury rates? Although the quality of the studies for this question was low, EAST conditionally recommended using NSAIDs in pain control regimens. In the higher-quality studies in this group, there was no increased risk of non-union.
Should ketorolac be used in analgesic regimens for adult patients with traumatic fracture versus routine analgesic regimens that do not include ketorolac to improve analgesia and reduce opioid use without increasing non-union
rates? This is the same question asked above, but with a specific drug rather than the class in general. The answer was basically the same.
Should selective NSAIDs (COX-2 inhibitors) be used in analgesic
regimens for adult patients (≥18 years old) with traumatic fracture versus routine analgesic regimens that include non-selective NSAIDs to improve analgesia and reduce opioid use without increasing non-union rates? COX-2 inhibitors are a subset of NSAIDs that are more selective in their action, blocking only the COX-2 receptor. Several years ago, there was a scandal regarding the COX-2 inhibitor rofecoxib (Vioxx). These selective drugs tended to have a higher incidence of cardiac complications. The manufacturer covered up this fact for several years, resulting in many unneeded deaths before it was removed from the market. The only COX-2 inhibitor available in the US is celecoxib. Only a few studies were performed using this drug during bone healing. There were not enough to make a recommendation.

Bottom line: EAST made conditional recommendations for using NSAIDs in general and ketorolac specifically in adults with fractures. “Conditional” only means that the authors did not have a consensus. Some voted to strongly recommend, and the remainder to conditionally recommend. There were no votes to recommend against their use.

The use of NSAIDs should complement a well-thought-out opioid regimen, which should also be combined with other non-narcotic medications and appropriate mobilization and therapy.

Reference: Efficacy and safety of non-steroidal anti-inflammatory
drugs (NSAIDs) for the treatment of acute pain after orthopedic trauma: a practice management guideline from the Eastern Association for the Surgery of Trauma and the Orthopedic Trauma Association. Trauma Surg Acute Care Open. 2023 Feb 21;8(1):e001056. doi: 10.1136/tsaco-2022-001056. PMID: 36844371; PMCID: PMC9945020.

Anatomy

What Is: The Tripod Fracture?

March 27, 2023 The Trauma Pro Leave a comment

The tripod fracture (officially known as the zygomaticomaxillary complex fracture, and sometimes called a malar fracture) is the most common one seen after trauma. Fundamentally, the zygoma is separated from the rest of the face in a tripod fracture.

As you might imagine (tripod fracture), there are three components to this fracture. The first is a fracture through the zygomatic arch (1). Next, the fracture extends across the floor of the orbit and includes the maxillary sinus (2). Finally, the fracture includes the lateral orbital rim and wall (3).

Extraocular muscles may become trapped in the fracture line, leading to diplopia. It is very important to do a good eye exam to try to detect entrapment. The infraorbital nerve also passes through the orbital floor and may be injured, leading to numbness along the lower eyelid and upper lip.

Nondisplaced fractures are treated symptomatically and reevaluated after a week or so to see if surgery would be beneficial. Displaced or symptomatic fractures require early open reduction. The pictures below show the anatomy of these fractures. They are derived from teaching materials provided by the Radiology Department at the University of Washington.

Resuscitation

Emergency Intubation: ED or OR?

March 24, 2023 The Trauma Pro Leave a comment

Decades ago, intubation of trauma patients only took place in the operating room, and only anesthesiologists performed it. As the discipline of Emergency Medicine came into being in the 1980s, emergency physicians became skilled in this procedure. Occasional trauma intubations had to occur in the ED, and typically anesthesia was called for it.

As the emergency physicians became more comfortable and improved their skills, they also started intubating. I distinctly remember a paper from the time (which I unfortunately do not have a reference to) stating that ED and OR intubation were equally safe if the ED intubation field could be made to look like the OR. This thinking has become commonplace, and in most trauma centers, intubation is now provided nearly exclusively by emergency physicians. Anesthesia is called only for extremely difficult cases.

But we have all been involved in cases where the patient is severely injured, usually hypotensive, and crashes and burns during or immediately after the procedure. This is likely due to a combination of loss of sympathetic tone due to the drugs administered, increased vagal tone from instrumenting the airway, and hypovolemia.

Authors from the University of Wisconsin, University of Pennsylvania, and Johns Hopkins hypothesized that ED intubation for patients requiring urgent operation for hemorrhage control was associated with adverse outcomes. They performed a three-year registry study from the National Trauma Program Databank of patients requiring laparotomy for hemorrhage control within 60 minutes of arrival. They excluded the dead and nearly dead (DOA, ED thoracotomy) and patients with immediate indications for intubation (head, neck, or facial trauma). They compared mortality, ED dwell time, blood transfusions, and major complications between patients with ED vs. OR intubation.

Here are the factoids:

Nearly 10,000 patients from 253 Level I or II trauma centers were included in the study
About 20% of patients underwent intubation in the ED, and they were more likely to have blunt trauma mechanism and higher ISS (22 vs. 17)
Initial vital signs were not clinically significant between the ED and OR groups
Mortality in the ED group was significantly higher (17% vs. 7%), the ED dwell time was significantly longer ( 31 vs. 22 minutes), required significantly more blood transfusion (6 vs. 4 units), and had a significantly higher risk of major complications (specifically cardiac arrest, AKI, and ARDS)
There was a wide variation in the rate of ED intubation across all the hospitals. Centers with the highest rate of ED intubations were 5x more likely to intubate than the lowest rate centers. The patient case mix could not explain this difference.
The lower ED intubation rate hospitals tended to be nonprofit Level I university hospitals
Centers with high levels of hemorrhage control surgery were more likely to intubate in the OR

Bottom line: From a purely technical perspective, the old dogma about patient location not making a difference is basically true. The process of getting an airway safely into the patient and secured is equivalent wherever it is done as long as the lighting, equipment, and skill levels are equivalent.

But when one considers the physiologic aftermath of this process, things are obviously more nuanced. Actively bleeding patients are extremely challenged, down to their organ and cellular levels. Disrupting their normal compensatory mechanisms is clearly associated with a significant downside.

We should clearly distinguish the patient who needs an airway for airway’s sake or cerebral protection from one who needs to be in the OR for bleeding control. Other papers have shown that mortality increases as each minute ticks by in the hemorrhaging patient. Trauma programs need to monitor these patients and do a performance improvement deep dive into all trauma patients intubated in the ED to ensure appropriate decision-making.

Reference: Emergency Department Versus Operating Room Intubation of Patients Undergoing Immediate Hemorrhage Control Surgery. Journal of Trauma and Acute Care Surgery, Publish Ahead of Print
DOI: 10.1097/TA.0000000000003907

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