All posts by The Trauma Pro

Head

What Is The Zumkeller Index in TBI?

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Here’s something you may not have heard of before: the Zumkeller index. Most trauma professionals who take care of serious head trauma have already recognized the importance of quantifying extra-axial hematoma thickness (HT) and midline shift (MLS) of the brain. Here’s a picture to illustrate the concept:

Source: Trauma Surgery Acute Care Open

Zumkeller and colleagues first described the use of the mathematical difference between these two values in prognosticating outcomes in severe TBI in 1996.

Zumkeller Index (ZI) = Midline shift (MDI) – Hematoma thickness (HT)

Intuitively, we’ve been using this all along. At some point, we recognized that if the degree of midline shift exceeds the hematoma thickness, it’s a bad sign. The easiest way to explain this is that there is injury to the brain that is causing swelling so the shift is greater than the size of the hematoma. 

The authors of a recent paper from Brazil decided to quantify the prognostic value of the ZI by doing a post-hoc analysis of a previously completed prospective study.  They limited their study to adult patients with an acute traumatic subdural hematoma confirmed by CT scan. It used data from the 4-year period from 2012-2015.

They compared demographics and outcomes in three cohorts of ZI:

  • Zero or negative ZI, meaning that the midline shift was less than the size of the hematoma
  • ZI from 0.1 mm to 3.0 mm
  • ZI > 3.0 mm

And here are the factoids:’

  • A total of 114 patients were studied, and the mechanism of injury was about 50:50 from motor vehicle crashes vs falls
  • About two thirds were classified as severe and the others were mild to moderate, based on GCS
  • Median initial GCS decreased from 6 in the low ZI group to 3 in the highest ZI group, implying that injuries were worse in the highest ZI group
  • Mortality (14-day) was 91% in the highest ZI group and only in the low 30% range in the others
  • Regression analysis showed that patients with ZI > 3 had an 8x chance of dying within 14 days compared to the others

Source: Trauma Surgery Acute Care Open

Bottom line: This study confirms and quantifies something that many of us have been unconsciously using all along. Of course there are some possible confounding factors that were not quantified in this study. Patients with the more severe injuries tended to also have subarachnoid hemorrhage and/or intra-ventricular blood. Both are predictors of worse prognosis. But this is a nice study that quantifies our subjective impressions.

The Zumkeller Index is an easily applied tool using the measuring tool of your PACS application. It can be used to determine how aggressively to treat your patient, and may help the neurosurgeons decide who should receive a decompressive craniectomy and how soon.

So now go out and amaze your friends! You’ll be the life of the party!

Reference: Mismatch between midline shift and hematoma thickness as a prognostic factor of mortality in patients sustaining acute subdural hematomaTrauma Surgery & Acute Care Open 2021;6:e000707. doi: 10.1136/tsaco-2021-000707

Trauma Center

Trauma Transfers Discharged From The ED

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Aren’t these embarrassing? A referring center sends you a patient with the idea that they will be evaluated and admitted to your hospital. But it doesn’t work out that way. The patient is seen, possibly by a surgical specialist, bandaged up, and then sent home. Probably to one that is quite a few miles away. Not only is this a nuisance for the patient and an embarrassment for the sending center, it may use resources at the trauma center that are already tight.

Transfer patients who are seen and discharged are another form of “ultimate overtriage.” In this case, the incorrect triage takes place at the outside hospital.  The trauma group in Oklahoma City reviewed their experience with these patients over a two year period. They looked exclusively at patients who were transferred in to a Level I center and then discharged.

Here are the factoids:

  • A total of 2,350 patients were transferred in, and 27% were transferred home directly from the trauma bay (!)
  • The three most common culprits by injury pattern were face (51%), hand (31%), isolated ortho injury (9%)
  • A third of these patients required a bedside procedure, including laceration repair (53%), eye exam (24%), splinting (18%), and joint reduction (5%)
  • Ten facilities accounted for 40% of the transfers

The authors concluded that the typical injuries prompting transfer are predictable. It may be possible to reduce the number of transfers by deploying telemedicine systems to push evaluations out to the referring hospitals.

Bottom line: This is quite interesting. Anyone who works in a Level I or II center is aware of this phenomenon. This abstract went a step further and quantified the specific issues involved. This center ended up discharging over 300 patients per year after transfer in. This is a tremendous drain on resources by patients who did not truly have the need for them.

The authors speculate that telemedicine evaluation may help reduce some of those transfers. This seems like an easy solution. However, it also poses a lot of issues in terms of who will actually staff the calls and how will they be compensated for their time.

There are a number of important take-aways from this abstract:

  1. Know your referring hospitals. In this study, there were 10 hospitals that generated an oversize number of referrals. Those are the targets / low hanging fruit. Identify them!
  2. Understand what their needs are. Are they frequently having issues with simple ortho injuries? Eye exams? This is what they need!
  3. Provide education and training to make them more comfortable. This allows you to target those hospitals with exactly the material they need and hopefully make them more self-sufficient.

This allows the higher level centers to reserve phone and/or telemedicine consultation for only the most ambiguous cases. It’s a better use of telehealth resources that may be needed, typically at night and on weekends.

Reference: Trauma transfers discharged from the emergency department-Is there a role for telemedicine? J Trauma Acute Care Surg. 2022 Apr 1;92(4):656-663. 

General

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

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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!

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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?

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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.

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