All posts by TheTraumaPro

Early Antibiotic Administration In Open Fractures

Recommendations for open fracture management has evolved over the past 20 years. The old-timey rule used to be: all open fractures need to be treated within 8 hours. This treatment could be washout and ORIF, washout and external fixation, or just washout alone. The washout was the constant across all types of management.

Then the orthopedics literature began to suggest that “lesser” fractures (Gustilo I – II) could go a bit longer. Some centers extended their required time to washout up to 12 or even 16 hours. Subsequently, the value of early IV antibiotics was recognized, and the time to washout started to change again.

Now, we have recommendations for early IV antibiotics competing with the old recommendations for prompt washout. Who is winning?

There are two recent papers that seem to provide conflicting recommendations regarding antibiotics. The first is in process for publication by the ortho group at San Francisco General Hospital. They studied 230 open fracture patients at their Level I Trauma center over a five-year period. They monitored for surgical site infection that occurred during the first 90 days after injury.

Here are the factoids:

  • It took 450 consecutive patients to find the 230 study patients due to these exclusion criteria: missing documentation of antibiotic administration, delayed presentation, and loss to followup
  • There were 169 Gustilo Type I or II fractures and 61 Type III fractures
  • They noted a trend (p = 0.053) toward infection in patients who had antibiotic administration an average of 83 minutes after arrival vs those who received them within one hour
  • Patients who received their antibiotics 2 hours after arrival had a 2.4x increase in likelihood for infection within 90 days

But there was another paper published in the same journal this year that shows the opposite result. This one is from the University of Bristol in the UK. This one reviewed only Gustilo Type III fractures and observed changes in the deep infection rate, before and after the National Health Service guidance on antibiotic administration changed from within three hours to one hour post-injury.

Some more factoids for you:

  • A total of 176 patients were identified at a single center, and only 152 were left after the usual exclusions
  • Average time to antibiotic administration decreased from 180 minutes to 160 minutes after the new guidance was issued (60 minutes(!))
  • Only 12 patients developed deep infections with a median followup of 26 months
  • On regression analysis, no obvious factors  for increased risk were identified

Bottom line: So what gives? Two different answers: antibiotics given after 2 hours is associated with an increased risk of infection, vs no difference?

No, not really. Talk about apples to bananas. The first study looks at all open fractures, not just the most severe. It does not really define “surgical site infection,” so can we assume it was any infection? We don’t know. The second study looked only at deep infections.

The sample sizes are marginal in both studies, although the first was able to show a significant result despite this. And, of course, these are association studies, so other factors could be at play to manifest an infection or not. Both groups showed an 8-11% infection rate of some kind in their Gustilo Grade III fractures. 

But the biggest issue with the second study is that, despite guidance that antibiotics should be given within an hour, the average time decreased from 3 hours to only 2:40. This is still beyond the two hour threshold to higher infection rates suggested in the first paper.

So what do I make of all of this? The UK paper is lacking the power and enough of a treatment change to be taken seriously. The San Francisco paper shows borderline results with a 2.4x increase in all infections if antibiotics are given after 2 hours. 

So until we have better data and larger series, 1 hour antibiotic administration seems like a painless way to decrease the likelihood of an infection. But whether that can safely delay the time to washout remains to be seen.

References:

  • Delay of Antibiotic Administration Greater than 2 Hours Predicts Surgical Site Infection in Open Fractures. Injury, in press, May 29, 2020.
  • Time to intravenous antibiotic administration (TIbiA) in severe open tibial fractures: Impact of change to national guidance. Injury 51:1086-1090, 2020.

Announcing My New Trauma PI Website!

For my audience members who have an interest in trauma performance improvement (PI), I have a special announcement. I’ve officially unveiled by new website dedicated exclusively to that topic.

You can find it at TraumaMedEd.com. There, you will find a growing collection of instructional videos, courses, PI blog posts, and downloadable materials. I am migrating the entire library of my trauma newsletters to the site as well.

My intent is to provide performance improvement information that you want to know about. To that end, I encourage you to sign up on the site and let me know what topics really interest you.

And if performance improvement is just not your thing, keep reading this blog!

I just released an 8-minute video detailing “When The Trauma PI Clock Starts Ticking.” Click the link or picture below to head over to the site and view it.

And please follow the new site on Facebook and Twitter, and use those platforms to send me topics to include in future content.

Enjoy!
Michael

 

Epidural Hematoma Treated With Middle Meningeal Artery Embolization

Epidural hematoma is a life-threatening condition that is typically associated with arterial bleeding outside of the dura. Most frequently, this is due to a skull fracture that extends across and lacerates the middle meningeal artery (MMA).

The standard treatment regimen is neurologic monitoring in patients who have a (nearly) normal GCS and do not change neurologically. That escalates to rapid craniectomy and evacuation in those with neurologic compromise.  Interestingly, there have been a few case reports over the last 10 years describing attempted management by embolization of the MMA.

Let’s look at this idea more critically. This seems like it should be a good idea. But remember, in medicine you’ve actually got to study it. There are too many examples of things that make sense that are worthless or actually cause harm.

The first report I found was a series of one in which the patient was found to have a large subdural hematoma. He was taken to surgery and the lesion was evacuated. However, there was persistent epidural bleeding intraop which was thought to be controlled. Repeat scan the next day showed a large epidural, so he was returned to the OR. Once again, there was persistent epidural oozing and the collection was removed. Followup CT showed yet another epidural. The patient was finally taken to interventional radiology for embolization of the MMA. This was successful, and the patient had no further recurrences.

This case provided proof of concept, although the bleeding was not due to known traumatic injury to the MMA. Last year, another case report was published that described an experience (of one again) with a young male who was found down. He awakened and then became obtunded again. CT showed bilateral epidural hematomas. He was taken to the OR for operative evacuation of the larger one. Postop CT showed expansion of the smaller one.

The patient was then taken to the endovascular suite and MMA embolization was carried out. The hematoma stabilized and the patient was later discharged without sequelae.

This case was trauma-related, but not for an acute bleed. Now, let’s look at a bigger case series to see how well this works. This one detailed the experience of a neurosurgery group in Sao Paulo, Brazil. All patients who underwent conservative management based on “standard criteria” were studied. Patients with large hematomas, midline shift, depressed skull fracture, coagulopathy, or incomplete data were excluded. One third of the injuries were due to falls, and the rest were due to other blunt mechanisms.

Here are the factoids:

  • 85% had an attendant skull fracture
  • About 82% had active extravasation from the MMA
  • All patients had followup CT scan 1-7 days after the procedure, and no increase in epidural size was noted
  • None of the patients had a change in GCS or needed operative intervention
  • The authors compared these results to historical controls from other published literature

Bottom line: Sounds impressive, right? But not so fast, there are a lot of loose ends here. First, these are supposedly all patients with epidural hematoma who were treated without operation. Decision to operate was based on criteria set out in a paper published 15 years ago. This strains the imagination a bit. There is usually no uniformity in the way individual neurosurgeons decide to operate, so it is likely there may be some significant selection bias here. It is very easy to believe that patients who were predicted to do well were the only ones enrolled in the study. This also explains why the authors had to use controls from other authors’ research for outcome comparison.

The results are too clean as well. No adverse events. No patients who ended up needing surgery. Followup scans were performed any time between postop day 1 and 7, but there is no frequency breakdown. If most of the repeat scans were performed near the beginning of the postop period, little change would be expected. MMA embolization is either a miracle cure or …

You know what they say, “if it seems to good to be true…” A single case series like this should never change one’s practice. Middle meningeal artery embolization sounds like common sense, but the devil is always in the details. This concept needs a lot more study before you should ever consider it in your patients. Or, you could start a real, IRB-approved study and make an excellent contribution to the neurosurgery literature.

References:

  1. Embolization of the Middle Meningeal Artery for the Treatment of Epidural Hematoma. J Neurosurg 110(6):1247-1249, 2009.
  2. Middle Meningeal Artery Embolization for the Treatment of an Expanding Epidural Hematoma. World Neurosurg 128:284-286,2019
  3. Endovascular Management of Acute Epidural Hematomas: Clinical Experience With 80 Cases. J Neurosurg 128(4):1044-1050, 2018.

What Is: A Rubber Bullet?

The protests in cities across the country continue. Many are peaceful, but not all. In some cases, police have resorted to “non-lethal” weapons to control and disperse crowds.

Although these weapons are called non-lethal, that’s not entirely true. The projectiles, gases, and powders that are being used all have some degree of morbidity and mortality. They are certainly less so than traditional projectiles (bullets), but serious and fatal injures can and do occur.

One item that is talked about in the news is the rubber bullet. What are these, exactly? The generic term is a “kinetic impact projectile” (KIP). It encompasses a variety of objects that are not designed to penetrate flesh like a regular bullet. They can be bullets, beanbags, sponges, pellets, and other odds and ends.

And the so-called “rubber bullet” isn’t even necessarily made of rubber. It can be plastic, metal, rubber, or other substances.

There is very little published data on injuries caused by KIPs. Because of their odd shapes, they tend to tumble when they are fired. This decreases aiming accuracy substantially when the target is distant. They are designed to be aimed at the lower extremities. However, if the aim is too high or the round is fired at close range, it can be lethal.

Here are some typical injuries that have been descirbed:

  • Subdural and intraparenchymal hematomas
  • Skull and facial fractures
  • Eye injuries leading to blindness (this happened to a photographer in Minneapolis last week)
  • Rib fractures and pulmonary contusions
  • Spleen laceration
  • Blunt intestinal injury

Here’s a video from one of the manufacturers that shows the amount of target deformation caused by a sponge tipped bullet. Very impressive.

(Tumblr viewers please click here to view video)

Bottom line: Although they sound relatively innocuous, kinetic impact projectiles of any kind are far from it. If you are called to treat a patient who has been shot with one, be sure to do a very thorough evaluation. Most head, neck, and torso injuries should undergo CT scanning to delineate deep or occult injuries in detail. In-hospital observation of torso injuries is warranted, as well as a good tertiary exam.

More On Lead Poisoning And Retained Bullets

Trauma professionals frequently have to leave bullets in patients. It is often more disruptive to go digging the projectiles out than to just leave them in place. But patients always want to know why and what the consequences might be.

In my last post, I discussed a very old paper on what we know about lead levels and retained bullets. Very recently, a meta-analysis was published that provides a better picture of this topic. They somehow managed to find over 2000 articles dealing with lead toxicity and bullets out there. But after someone had the pleasure of reviewing each of them, they found only 12 that had any meaningful or actionable information.

Here are the factoids:

  • All studies were observational (duh! It would be difficult to get your IRB to approve a study where patients were shot on purpose)
  • There were five cross-sectional studies, four case-control studies, and three prospective cohort studies
  • The studies were small, with a median of only 26 patients (range 15-120)
  • Eleven of the twelve studies showed an association with retained bullets and elevated blood lead levels
  • Three studies showed elevated blood levels if a fracture was present
  • The higher the number of retained fragments, the more likely lead levels were to be high
  • Higher lead levels were associated with retained fragments near a bone or joint
  • There were no good correlations with number of fragments and location vs actual lead toxicity

Bottom line: Even using meta-analysis, it is difficult to tease out meaningful answers to this question. That speaks to the low numbers of papers and their quality. However, this study does provide a little bit of guidance.

Retained bullet fragments are probably not a big worry in most patients. The bothersome cases are those where the fragments are in or near a bone or joint. And even though few patients actually developed lead toxicity, lead levels approaching 5 micrograms/dL can have physiologically significant negative effects. 

Recommendation: If your patient has a retained bullet fragment near a bone or joint, or they have “multiple” retained fragments (no good definition of this), they should have blood lead levels measured every three months for a year. If the level is rising, and certainly if it reaches the 5μ/dL level, attempts should be made to remove the fragments.

Reference: Lead toxicity from retained bullet fragments: A systematic review and meta-analysis. J Trauma 87(3):707-716, 2019.