Category Archives: Complications

Complications, Device

Air Embolism From an Intraosseous (IO) Line

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Intraosseous (IO) lines are a godsend when we are faced with a patient who desperately needs access but has no veins. The tibia is generally easy to locate and the landmarks for insertion are straightforward. They are so easy to insert and use, we sometimes “set it and forget it”, in the words of infomercial guru Ron Popeil.

But complications are possible. The most common is an insertion “miss”, where the fluid then infuses into the knee joint or soft tissues of the leg. Problems can also arise when the tibia is fractured, leading to leakage into the soft tissues. Infection is extremely rare.

This photo shows the inferior vena cava of a patient with bilateral IO line insertions (black bubble at the top of the round IVC).

During transport, one line was inadvertently disconnected and probably entrained some air. There was no adverse clinical effect, but if the problem is not recognized and the line is not closed properly, there could be.

Bottom line: Treat an IO line as carefully as you would a regular IV. You can give anything through it that can be given via a regular IV: crystalloid, blood, drugs. And even air, so be careful!

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Complications, Device

Should I Apply Compression Devices To Patients With DVT?

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Everyone knows that venous thromboembolism (VTE) is a potential problem in hospitalized patients, and especially so in trauma patients. Several groups of them are at higher risk by virtue of the particular injuries they have sustained and the activity restriction caused.

Nearly every trauma program uses some form of screening and prophylaxis in an attempt to reduce the occurrence of this problem, which can result in deep venous thrombosis (DVT) and/or pulmonary embolism (PE). Screening looks at patient factors such as age, obesity, and previous VTE, as well as injury risk factors like spine and pelvic fractures and decreased mobility.

Based on the screening protocol, prophylaxis may be prescribed depending upon the level of VTE risk, which is then balanced with bleeding risk from the brain, solid organ, or other injuries. The choices we have are primarily mechanical vs chemical and consist of compression devices (sequential or not) and various heparins.

But an age-old question continues to resurface: if a patient breaks through their prophylaxis and develops DVT, is it safe to apply compression devices to the extremity?

There has always been the fear that doing things that increase flow in the affected extremity may cause clots to dislodge and ultimately cause a PE. Seems logical, right? But we know that often, our common sense about things is completely wrong.  Couldn’t just moving around cause pieces to break off? A meta-analysis of 13 studies published in 2015 showed that early ambulation was not associated with a higher incidence of new PE. Furthermore, patients who suffered from pain in the affected extremity noted significant improvements with early ambulation.

If ambulation makes the pain better, could the veins be recanalizing more quickly? Another study examined a small group of 72 people with DVT receiving anticoagulants, half of whom were prescribed exercise and compression stockings and the other half stockings only. There was a huge amount of variability in the rates of recanalization, but ultimately, there were no significant differences with or without exercise.

So just lying in bed is not good, and exercise/ambulation may actually make people feel better. But interestingly, bedrest alone does not appear to increase the likelihood of PE! It does decrease the risk of developing problems other than the VTE, like pulmonary complications.

But what about compression devices? Common sense would say that you are intermittently  increasing pressures in the leg veins, which could dislodge any loose clots and send them flying to the lungs, right?

Unfortunately, I couldn’t find a paper from anyone who had the courage to try this. Or perhaps no institutional review board (IRB) would approve it. But the key fact is that every compression device manufacturer includes existing DVT as a contraindication in their product documentation. They don’t have any literature either, so I assume it’s an attempt to limit litigation, just in case.

Bottom line: Walking provides at least as much muscle compression as compression devices. But the simple truth is that we have no solid research that either supports or condemns the use of active compression devices in patients with known DVT. And we probably won’t, ever.

Compression stockings seem to be safe, but they really don’t do much. They are white, but don’t do much more than contribute to hospital clothing fashion. Since the manufacturers define existing DVT as a contraindication, application of their product would be considered an off-label use. So it looks like we cannot in good faith use these devices in patients with diagnosed DVT.

References:

  • Bed Rest versus Early Ambulation with Standard Anticoagulation in The Management of Deep Vein Thrombosis: A Meta-Analysis. PLOS One , April 10, 2015, https://doi.org/10.1371/journal.pone.0121388
  • Bed Rest or Ambulation in the Initial Treatment of Patients With Acute Deep Vein Thrombosis or Pulmonary Embolism: Findings From the RIETE Registry. Chest 127(5):1631-1636, 2005.
  • Does supervised exercise after deep venous thrombosis improve recanalization of occluded vein segments? A randomized study. J Thrombosis Thrombolysis 23:25-30, 2006.
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Complications, Thorax

Early Vs Delayed Thoracic Endovascular Repair

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Back in the day, the only way to fix a broken thoracic aorta was via left thoracotomy.  This was a big procedure, with the possibility of several major complications, with postop paraplegia being one of them. At the time, there was a debate about whether the procedure should be done immediately versus waiting until the patient was well-resuscitated. The concern was that death was nearly certain if the aortic lesion progressed.

We learned that temporizing with strict blood pressure control worked wonders at protecting the patient. Although many of these injuries were managed within hours, a growing number were delayed by a few days to improve outcomes.

Nowadays, thoracic endovascular aortic repair (TEVAR) is routine and much less morbid than the open procedure. However, the same question arises: do it early or wait a while? Interestingly, not one but two analyses have been published on this very topic in the last four months!

The first is from an international research group that searched the usual databases and initially found 921 records. They included only clinical trials or cohort studies with ten or more adult patients that could be stratified as early (within 24 hours) or late (after 24 hours) intervention. After applying these criteria, only seven studies remained for analysis.

There were 3,757 patients with early repairs, compared to 1,238 undergoing late repair. The presenting demographics and injury grades were similar in each group. However, the short-term mortality was significantly higher (1.9x) in the early TEVAR group. Additionally, ICU length of stay was significantly longer (3 days) in the late TEVAR group.

The second paper was presented as a quick-shot at last year’s AAST meeting. It is from a group of researchers from our big Boston trauma centers and the Netherlands. They used four years of data from the TQIP database, giving them extra information unavailable in the first study. They specifically looked at patients with grade II or III injuries. Here is the grading scale:

Here are the factoids:

  • A total of 1,339 patients were studied, with about three-quarters in the early TEVAR group
  • Median time to TEVAR was 4 hours in the early group and 65 hours in the late group
  • Patients in the early group were significantly less likely to have brain or liver injuries
  • ISS was similar in both groups
  • The early TEVAR group had significantly higher in-hospital mortality (16% vs. 5%), significantly higher risk of ARDS (7.6% vs. 2.1%), but significantly shorter ICU stay (7 vs 10 days)
  • When patients who died within the first 24 hours were excluded, the in-hospital mortality remained significantly higher, and the ICU and hospital lengths of stay were significantly shorter

Bottom line: Some society guidelines began recommending delayed TEVAR in 2015. This study did not detect any trend toward this, however. Using different methods and databases, these two studies identified nearly identical mortality and ICU trends in large groups of patients. The mortality trends do not appear to be related to injury grade, overall injury severity, or the presence of head injury. 

Taken together, this suggests that we need to rethink the timing of TEVAR in patients with grade II or III injuries. The best timing still needs to be defined, but it appears to be beyond 24 hours. Centers performing this procedure should review their results and consider extending procedure timing as additional research is done to define the ideal time interval.

References:

  1. Early Versus Delayed Thoracic Endovascular Aortic Repair for Blunt Traumatic Aortic Injury: A Systematic Review and Meta-Analysis. Cureus. 2023 Jun 28;15(6):e41078. doi: 10.7759/cureus.41078. PMID: 37519486; PMCID: PMC10375940.
  2. Early Versus Delayed Thoracic Endovascular Aortic Repair for
    Blunt Thoracic Aortic Injury: A Propensity Score-Matched Analysis. Ann Surg 278:e848-e854, 2023.

 

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Complications

Back Braces: Are They Really Needed?

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Back braces have always confused me. There are so many types: TLSO, LSO, backpack, extension, and even the lowly abdominal binder can function as a brace. And I have never been able to predict which brace my spine colleagues accurately would prescribe for a specific condition or injury.

Many vertebral fractures can be treated non-operatively. And it seems intuitive that there would be some benefit from splinting the spine to limit the range of motion to enhance healing. So I would like to concentrate on some papers that examined the use of back braces on patients who underwent pedicle screw fixation of their thoracic and/or lumbar spine fractures. 

I found two systematic reviews and a ten-year prospective clinical trial. First, the reviews.

The first was published in 2016 and examined papers comparing postop bracing vs. no postop bracing. It looked at loss of deformity correction, return to work, functional improvement, instrumentation failure rate, pseudoarthrosis, and postop complications. A total of 76 studies were included.

The average wear time for the braces was just over three months. There was no difference in pain, return to work, functional outcome, or instrumentation failure. Interestingly, there was a significant increase in the number of patients who lost kyphotic reduction from the procedure and a significant increase in the number of complications. Unfortunately, the authors did not break out specific complications other than wound infections. Although these were higher in the braced group (2.8% vs. 1.8%), this difference was not significant. One real positive for the brace: the number of pseudoarthroses was significantly less (2.4% vs. 6%).

The next review looked at postoperative bracing from a cost-effectiveness standpoint. It considered adverse events such as infections and hardware failure and examined a total of 1957 patients across 48 papers. Non-braced patients were somewhat older. Braced patients had significantly fewer reoperations for non-union or hardware failure (1.3% vs. 1.8%). There was no difference in wound dehiscence or infection. Overall, there was no cost benefit to applying a back brace in these patients after pedicle screw fixation. 

The last paper was a prospective clinical trial that enrolled 144 patients randomized to brace or no brace after their surgical procedure. They underwent multiple postop evaluations to monitor quality of life, success of the fusion, pain, mobility, and return to previous activities.

Here are the factoids:

  • Mean age was only 34 years, and only fractures of T11 to L5 were included
  • Two-thirds of the injuries were due to falls, and most of the remaining ones were from car crashes
  • Three-quarters were burst fractures, and the remaining were wedge or fracture-dislocation injuries
  • There were no differences in early mobilization, residual pain, return to previous activities, quality of life, or success of the fusion after one year

The authors concluded that the use (or non-use) of a TLSO brace after pedicle screw fixation of these fractures does not affect treatment. They state that TLSO braces are not required in the postop period for these patients.

Bottom line: Interesting, yet slightly confusing. The systematic reviews show a significant increase in pseudoarthrosis in patients without braces. This was not seen in the prospective study. The discrepancy could be due to the quality of the papers included in the reviews or insufficient power in the prospective study. So it may be too early to fully know the difference. But it appears to be so small that the question of whether a brace is really necessary needs to be asked. 

Most braces are expensive and uncomfortable. I have seen several patients in follow-up who basically stopped wearing their brace as soon as they were out of the hospital. And anecdotally, they did fine. 

A large, multicenter study in progress in the Netherlands will analyze the same factors listed above.  Unfortunately, the listing on clinicaltrials.gov indicates they are only recruiting 45 patients, which may not add much to what is already known due to low statistical power.

In the meantime, consider discussing with your spine surgeons reviewing the current literature on back bracing. It may be possible to reduce the number of eligible patients who take their brace home and use it as a chew toy for the dog. 

References:

  1. Bracing After Surgical Stabilization of Thoracolumbar Fractures: A Systematic Review of Evidence, Indications, and Practices. World Neurosurg 93:221-228, 2016.
  2. Post-operative bracing after pedicle screw fixation for thoracolumbar burst fractures: A cost-effectiveness study. J Clin Neurosci 45:33-39, 2017.
  3. Evaluation of postoperative bracing on unstable traumatic lumbar fractures after pedicle screw fixation. Int J Burns Trauma 12(4):168-174, 2022.
  4. Is postoperative bracing after pedicle screw fixation of spine fractures necessary? Study protocol of the ORNOT study: a randomised controlled multicentre trial. NCT03097081. Listed in 2017, to be completed Nov 2026.
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Complications

How Much Fetal Radiation Exposure In Imaging Studies?

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I periodically publish a chart that shows how much radiation exposure our patients get from various trauma imaging studies. For reference, here it is:

Test Dose (mSv) Equivalent background
radiation
Chest x-ray 0.1 10 days
Pelvis x-ray 0.1 10 days
CT head 2 8 months
CT cervical spine 3 1 year
Plain c-spine 0.2 3 weeks
CT chest 7 2 years
CT abdomen/pelvis 10 3 years
CT T&L spine 7 2 years
Plain T&L spine 3 1 year
Millimeter wave
scanner (that hands
in the air TSA thing at
the airport)		 0.0001 15 minutes
Scatter from a chest
x-ray in trauma bay
when standing one 
meter from the
patient		 0.0002 45 minutes
Scatter from a chest
x-ray in trauma bay
when standing three 
meters from the
patient		 0.000022 6 minutes

One of the issues that trauma professionals gnash our teeth about is how much radiation the baby gets when we perform these studies on pregnant women. Well, here is just what you need. Another chart! In order to avoid confusion, I will list effective doses to the fetus in milligrays (mGy), which is how much radiation is deposited in a substance. This is a little confusing, since doses are frequently listed in millisieverts which takes the specific organ and type of radiation into effect. In general, these two units are very similar for x-rays.

A useful rule of thumb is that if the fetal dose is less than 50 mGy during any trimester, the risk of an abortion or fetal malformation is about the same as from other risks to the pregnancy. The American College of Radiology notes that exposures less than 100 mGy are “probably too subtle to be clinically detectable.”

To help in your clinical decision making, I’ve added some extra information to the table regarding fetal exposure:

Test Adult Dose (mSv) Fetal Dose (mGy)
Chest x-ray 0.1 negligible
Pelvis x-ray 0.1 negligible
CT head 2 <1
CT head and C-spine 4 10
CT chest 7 <1
CT abdomen/pelvis 10 25
Pan Scan (CTA chest, abdomen, and pelvis) up to 68 up to 56
CT pulmonary angiogram up to 40 <1

Bottom line: We still have to think hard about how we image pregnant patients! There are some alternatives available to us, including the good old physical exam, conventional x-rays, and ultrasound. MRI is possible, but is a pain in the ass for many reasons. 

CT of the head and cervical spine are fine for both mother and baby, and non-contrast imaging of the torso is within accepted limits of fetal exposure. However, the whole point of the torso scan in CT is to identify critical injuries that may lead to exsanguination like solid organ and aortic injuries. In general, those scans should always be ordered with contrast. 

If clinical suspicion is high, it may be necessary to order these higher-dose studies anyway. If the mother has an unrecognized and potentially fatal injury, the baby will not survive either. There are many, many permutations of injuries and diagnostics. These cases will put your clinical judgment to the test, for sure!

References:

  • Imaging Pregnant and Lactating patients. RadioGraphics 35:6, 1751-1765, 2015.
  • Imaging of the pregnant trauma patient. RadioGraphics 34:3, 748-763,2014.
  • Fetal doses from radio logical examinations. Br J Radiol;72(860): 773–780, 1999.
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