Category Archives: Complications

Complications, Imaging

Best Of EAST #8: Timing Of Reimaging For BCVI

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There are still many questions regarding optimal management of blunt carotid and vertebral arterial injury (BCVI). We know that they may ultimately result in a stroke. And we kind of know how to manage them to try to avoid this. We also know that the grade may change over time, and many vascular surgeons recommend re-imaging at some point.

But when? There are still many questions. A multi-center trial has been collecting observational data on this issue since 2018. The group reviewed three years of data to examine imaging characteristics and stroke rate during the study period.

Here are the factoids:

  • A total of 739 cases were identified at 16 trauma centers
  • The median number of imaging studies was 2, with a range of 1-9 (!). Two thirds received only one study.
  • Injury grade distribution was as follows:
    • Grade 1 – 42%
    • Grade 2 – 30%
    • Grade 3 – 10%
    • Grade 4 – 18%
    • Grade 5 – <1%
  • About 30% changed in grade during the hospitalization, with 7% increasing and 24% decreasing.
  • Average time to change in grade was 7 days
  • Nearly 75% of those that decreased actually resolved. All of the grade 1 lesions resolved.
  • Stroke tended to occur after about one day after admission, although the grade 1 lesions took longer at 4 days
  • Strokes occurred much earlier than grade change

The authors concluded that there should be further investigation about the utility of serial imaging for stroke prevention.

Bottom line: This is basically a “how we did it” study to tease out data on imaging and stroke after BCVI. It’s clear that there is no consensus across trauma centers regarding if and when repeat imaging is done. And it’s not really possible to make any recommendations about repeat imaging based on this study.

However, it does uncover one important fact. It takes a week for the injury grade on CT to change, but strokes occur much earlier and usually within 24 hours! This is important because it makes it clear that it’s crucial to actually make the diagnosis early. Average stroke occurrence was 9% overall. Grade 1 injuries had only a 3% rate, but grades 2-4 were in the 12-15% range. Grade 5 had a 50% stroke rate!

These facts reinforce the importance of identifying as many of these BCVI as possible during the initial evaluation. The abstract I reviewed yesterday confirmed that the existing screening criteria (Memphis, Denver) will miss too many. More liberal imaging is probably indicated. If you missed the post, click here to view it in a new window.

Here are my comments for the authors and presenter:

  • The “change in BCVI grade over time” charts in the abstract are not readable. Please provide clear images during your presentation and explain what they mean. I was confused!
  • Based on your data, do you have any recommendations regarding the utility of re-imaging? Is it necessary in the same hospitalization at all? These patients will receive treatment anyway, and it doesn’t appear to have any impact on stroke rate.
  • Do you have any recommendations regarding the (f)utility of existing screening systems given the early occurrences of stroke in the study? Are you a fan of using energy / mechanism rather than a bullet list of criteria?

This is important work and I can’t wait to look at the data up close.

Reference: BLUNT CEREBROVASCULAR INJURIES: TIMING OF CHANGES TO INJURY GRADE AND STROKE FORMATION ON SERIAL IMAGING FROM AN EAST MULTI-INSTITUTIONAL TRIAL. EAST 35th ASA, oral abstract #34.

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Complications, Imaging

Best Of EAST #7: Routine Screening vs Denver Criteria For BCVI

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Currently, blunt carotid and vertebral artery injury (BCVI) is diagnosed using CT angiography of the great vessels and neck. This study is typically ordered when there is some degree of clinical suspicion based on the application of an established screening system. There are currently two such systems in use, Denver and Memphis.

I dedicated a week to BCVI earlier in the year. If you’d like to read the series, click here.

Both screening systems have been updated over the years. There is now a modified Memphis and an expanded Denver system. The reason for the modifications is simple: some patients were not flagged as at risk by the original versions of the systems. Does this mean we should screen more, or even screen everybody?

To answer this question, it’s important to have an idea of the number of patients who actually sustain the injury. This means having a liberal screening policy in place in the first place. The trauma group at Ascension St. Vincent Hospital in Indianapolis liberalized their criteria in 2012 and first published their experience in 2015. In this abstract, they examined their experience in screening all high-energy patients and reviewing how many patients would have been screened using the expanded Denver criteria.

Here are the factoids:

  • This is a single-center, retrospective study carried out over 5.5 years
  • A total of about 17,000 blunt trauma patients were seen, and about 30% underwent CTA neck for BCVI screening
  • About 1% of total patients screened were found to have BCVI, which was about 3% of those who underwent CTA
  • Sixteen percent of patients who actually had BCVI did NOT meet any of the expanded Denver criteria
  • Ten percent of patients with grades III-V injury did not meet any of the criteria

The authors concluded that using the expanded Denver criteria alone will result in missed injuries and that liberalized screen should be considered to decrease risk.

Bottom line: Once again, this is a paper that conforms to my own bias and experience, so I have to work to be critical of it. We have seen delayed diagnoses of this injury at our center using the standard criteria. For that reason, we recently implemented a guideline to add CTA neck on any patient with a mechanism sufficient to warrant CTA chest (we are not automatic pan-scanners).

This is a straightforward descriptive study at a center that has had a liberal BCVI screening guideline for nearly a decade. The only opportunity for bias lies in the specifics of the screening criteria. In St. Vincent’s case, it is simple: any patient with a mechanism sufficient to require CT cervical spine or chest received CTA neck as well.

I would argue that this might be a bit too liberal. There are many elderly patients who fall that require cervical spine CT, but the mechanism should be insufficient to sustain a BCVI. It can be an add-on study if fracture patterns are seen that fall within the Denver or Memphis criteria.

Here are my questions for the authors and presenter:

  • Why choose the Denver criteria? Why not look at Memphis, too? I’m sure you will find similar issues.
  • Did you analyze your elderly falls patients who got their CTA based on your cervical CT criterion? It seems like this could result in substantial overtriage. Did you actually detect any BCVI in this group if they didn’t have one of the classic fracture patterns?

This is an important abstract, and I’m looking forward to hearing all the specifics! It looks like it may be time to seriously consider the energy of the mechanism, if not ditch the criteria altogether.

Reference: ROUTINE CT SCREENING FOR BLUNT CEREBROVASCULAR INJURY IDENTIFIES INJURIES MISSED BY CLINICAL RISK FACTORS. EAST 35th ASA, oral abstract #35.

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Complications, Pharmacy

Best Of EAST #6: How Long Does Risk For VTE Last After Spine Fracture?

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Most trauma centers use an existing venous thromboembolism (VTE) guideline or have developed their own injury-specific one. These include risk factors, contraindications, specific agent, and dosing recommendations. But one thing most do not include is duration of prophylaxis!

The length of time a patient is at risk for VTE is not well delineated yet. The group at the University of Arizona decided to tackle this program using the National Readmission Database. This dataset is a comprehensive resource for critically analyzing patients who are discharged and readmitted, even for multiple occurrences. It covers 30 states and almost two thirds of the population.

The authors focused on VTE occurring during the first six months after injury. Patients who died on the initial admission, were taking anticoagulants, had spinal surgery, or sustained a spinal cord injury were excluded. Over 41,000 records from the year 2017 met these criteria.

Here are the factoids:

  • The average age was 61, which shows the skew toward the elderly with these injuries
  • Spine areas injured were cervical in 20%, thoracic in 19%, lumbar in 29%, sacrococcygeal in 11%, and multiple levels in 21%.
  • During the initial admission, 1.5% developed VTE: 0.9% were DVT and 0.7% were PE
  • Within 1 month of discharge, 0.6% of patients were readmitted for VTE: 0.4% DVT and 0.3% PE
  • In the first 6 months, 1.2% had been readmitted: 0.9% DVT and 0.6% PE
  • Mortality in the first 6 months was 6.7%
  • Factors associated with readmission for VTE included older age, discharge to a skilled nursing facility, rehab center, or care facility

The authors concluded that VTE risk remains high up to 6 months after conservatively managed spinal fractures. They recommend further study to determine the ideal prophylactic agent and duration.

Bottom line: This is a creative way of examining a difficult problem. We know that VTE risk does not stop when our patient is discharged. This is one of the few ways to get a sense of readmissions, even if it is not to the same hospital. And remember, this is an underestimate because it’s possible for a patient living near a state border to be re-hospitalized in a state not in this database.

This study might prompt us to prescribe up to six months of prophylaxis, particularly in seniors who are discharged to other care facilities.

Here are my questions for the author and presenter:

  • Is there any way to extrapolate your data to the entire population of the US, or to compensate for the “readmission over state lines” problem?
  • Is the odds ratio of 1.01 for risk of VTE in the elderly age group significant in any way? It seems like a very low number that would be easily overwhelmed by the “noise” in this data set.
  • Is the mortality number for all causes, or just VTE?

This is an intriguing study, and one that should influence the VTE guidelines in place at many trauma centers!

Reference: THE LONG-TERM RISKS OF VENOUS THROMBOEMBOLISM AFTER NON-OPERATIVELY MANAGED SPINAL FRACTURE. EAST 35th ASA, oral abstract #28.

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Complications, Thorax

Retained Hemothorax: The Practice Guideline

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Over the last few days, I’ve reviewed some data on managing hemothorax, as well as the use of lytics. Then I looked at a paper describing one institution’s experience dealing with retained hemothorax, including the use of VATS. But there really isn’t much out there on how to roll all this together.

Until now. The trauma group at Vanderbilt published a paper describing their experience with a home-grown practice guideline for managing retained hemothorax.  Here’s what it looks like:

I know it’s small, so just click it to download a pdf copy. I’ve simplified the flow a little as well.

All stable patients with hemothorax admitted to the trauma service were included over a 2.5 year period. The practice guideline was implemented midway through this study period. Before implementation, patients were treated at the discretion of the surgeon. Afterwards, the practice guideline was followed.

Here are the factoids:

  • There were an equal number of patients pre- and post-guideline implementation (326 vs 316)
  • An equal proportion of each group required an initial intervention, generally a chest tube (69% vs 65%)
  • The number of patients requiring an additional intervention (chest tube, VATS, lytics, etc) decreased significantly from 15% to 9%
  • Empyema rate was unchanged at 2.5%
  • Use of VATS decreased significantly from 8% to 3%
  • Use of catheter guided drainage increased significantly from 0.6% to 3%
  • Hospital length of stay was the same, ranging from 4 to 11 days (much shorter than the lytics studies!)

Bottom line: This is how design of practice guidelines is supposed to work. Identify a problem, typically a clinical issue with a large amount of provider care variability. Look at the literature. In general, find it of little help. Design a practical guideline that covers the major issues. Implement, monitor, and analyze. Tweak as necessary based on lessons learned. If you wait for the definitive study to guide you, you’ll be waiting for a long time.

This study did not significantly change outcomes like hospital stay or complications. But it did decrease the number of more invasive procedures and decreased variability of care, with the attendant benefits from both of these. It also dictates more selective (and intelligent) use of additional tubes, catheters, and lytics. 

I like this so much that I’ve incorporated parts of it into the chest tube guideline at my center!

Download the practice guideline here.

Related posts:

Reference: Use of an evidence-based algorithm for patients with traumatic hemothorax reduces need for additional interventions. J Trauma 82(4):728-732, 2017.

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Complications, Thorax

Surgical Management Of Retained Hemothorax – VATS

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I’ve written about the use of lytics to treat retained hemothorax over the past few days. Although it sounds like a good idea, we just don’t know that it works very well. And they certainly don’t work fast. Lengths of stay were on the order of two weeks in both studies reviewed.

The alternative is video assisted thoracoscopic surgery (VATS). So let’s take a look at what we know about it. This procedure is basically laparoscopy of the chest. A camera is inserted, and other ports are added to allow insertion of instruments to suck, peel, and scrape out the hemothorax.

A prospective, multi-center study was performed over a 2 year period starting in 2009. Twenty centers participated, contributing data on 328 patients with retained hemothorax. This was defined as CT confirmation of retained blood and clot after chest tube placement, with evidence of pleural thickening.

Here are the factoids:

  • 41% of patients had antibiotics given for chest tube placement (this is interesting given the lack of consensus regarding their effectiveness!)
  • A third of patients were initially managed with observation, and most of them (82%) did not need any further procedures (83 of 101 patients)
  • Observation was more successful in patients who were older, had smaller hemothoraces (<300cc), smaller chest tubes (!!, <34 Fr), blunt trauma, and peri-procedure antibiotics (?)
  • An additional chest tube was inserted in 19% of patients, image guided drain placement in 5%, and lytics in 5%. Half to two-thirds of these patients required additional management.
  • VATS was used in 34% of patients. One third of them required additional management including another chest tube, another VATS, or even thoracotomy.
  • Thoracotomy was most likely required if there was a diaphragm injury or large hemothorax (<900cc)
  • Empyema and pneumonia were common (27% and 20%, respectively)

Bottom line: There’s a lot of data in this paper. Most notably, many patients resolve their hemothorax without any additional management. But if they don’t, additional tubes, guided drain placement, and lytics work only a third of the time and contribute to additional time in the hospital. Even VATS and thoracotomy require additional maneuvers 20-30% of the time. And infectious complications are common. This is a tough problem!

Tomorrow, I’ll try to roll it all together and suggest an algorithm to try to optimize both outcomes and cost.

Reference: Management of post-traumatic retained hemothorax: A prospective, observational, multicenter AAST study. 72(1):11-24, 2012.

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