All posts by TheTraumaPro

How Common Is BCVI, Really?

Blunt carotid and vertebral artery injuries (BCVI) are an under-appreciated problem after blunt trauma. Several screening tools have been published over the years, but they tend to be unevenly applied at individual trauma centers. I will discuss them in detail in the next section.

For the longest time, the overall incidence of BCVI was thought to be low, on the order of 1-2%. This is the number I learned years ago, and it has not really changed over time.

But how do we know for sure? Well, the group at Birmingham retrospectively reviewed every CT angiogram (CTA) of the neck they did in a recent two-year period. They did this after adopting a policy of imaging each and every one of their major blunt trauma patients for BCVI. Each patient chart was also evaluated to see if the patient met any of the criteria for the three commonly used screening systems.

During the study period, a total of 6,287 of 6,800 blunt trauma patients underwent BCVI screening with CTA of the neck. They discovered that 480 patients (7.6%) were positive for BCVI!

This is a shocking 8x higher than we expected! Why hasn’t this been obvious until now? Most likely because we were previously only aware of patients who became symptomatic. Luckily, many of these patients dodge the proverbial bullet and never exhibit any symptoms at all.

So why should we be worried? This is one of those clinical entities like blunt thoracic aortic disruption that potentially has terrible consequences if ignored. Although the number of patients who develop sequelae from their BCVI is small, suffering a stroke can be catastrophic.

Should we perform a screening study for all blunt trauma patients? Seems like overkill, or is it? Is there any way we be more selective about it?

In the next post, I’ll review the three current screening tools  used to determine which patients should receive CTA, and how good they are.

Reference: Universal screening for blunt cerebrovascular injury. J Trauma 90(2):224-231, 2021.

It’s BCVI Week!

This post will kick off a series of posts on BCVI. What is that, you ask? There seems to be some confusion as to what the acronym BCVI actually stands for. Some people believe that it means blunt cerebrovascular injury. This is not correct, because that term refers to injury to just about any vessel inside the skull.

The correct interpretation is blunt carotid and vertebral artery injury. This term refers to any portion and any combination of injury to those two pairs of vessels, from where they arise on the great vessels, all the way up into the base of the skull. Here’s a nice diagram:

Note that we will be excluding the external carotid arteries from this discussion, since injuries to them do not have any impact on the brain. They can cause troublesome bleeding, though.

These arteries are relatively protected from harm during blunt trauma. But given enough energy, bad things can happen. Fortunately, injuries to these structures are not very common, but unfortunately many trauma professionals under-appreciate their frequency and severity.

Over the next four posts, I’m going to provide an update on what we know about BCVI. I will try to tease out the true incidence, review the (multiple) screening systems, and discuss various ways to manage these injuries.

In the next post, we’ll explore the incidence of this injury. Is it truly as uncommon as we think?

Why Do Trauma Patients Get Readmitted?

Readmission of any patient to the hospital is considered a quality indicator. Was the patient discharged too soon for some reason? Were there any missed or undertreated injuries? Information from the Medicare system in the US (remember, this represents an older age group than the usual trauma patient) indicates that 18% of patients are readmitted and 13% of these are potentially preventable.

A non-academic Level II trauma center in Indiana retrospectively reviewed their admissions and readmissions over a 3 year period and excluded patients who were readmitted on a planned basis (surgery), with a new injury, and those who died. This left about 5,000 patients for review. Of those, 98 were identified as unexpected readmissions. 

There were 6 major causes for readmission:

  • Wound (23) – cellulitis, abscess, thrombophlebitis. Two thirds required surgery, and 4 required amputation. All of these amputations were lower extremity procedures in obese or morbidly obese patients.
  • Abdominal (16) – ileus, missed injury, abscess. Five required a non-invasive procedure (mainly endoscopy). Only 2 required OR, and both were splenectomy for spleen infarction after angioembolization.
  • Pulmonary (7) – pneumonia, empyema, pneumothorax, effusion. Two patients required an invasive procedure (decortication, tube placement).
  • Thromboembolic (4) – DVT and PE.  Two patients were admitted with DVT, 2 with PE, and 1 needed surgery for a bleed due to anticoagulation.
  • CNS (21) –  mental status or peripheral neuro exam change. Eight had subdural hematomas that required drainage; 3 had spine fractures that failed nonoperative management.
  • Hematoma (5) – enlargement of a pre-existing hematoma. Two required surgical drainage.

About 14% of readmissions were considered to be non-preventable by a single senior surgeon. Wound complications had the highest preventability and CNS changes the lowest. Half occurred prior to the first followup visit, which was typically scheduled 2-3 weeks after discharge. This prompted the authors to change their routine followup to 7 days.

Bottom line: This retrospective study suffers from the usual weaknesses. However, it is an interesting glimpse into a practice with fewer than the usual number patients lost to followup. The readmission rate was 2%, which is pretty good. One in 7 were considered “preventable.” Wounds and pulmonary problems were the biggest contributors. I recommend that wound and pulmonary status be thoroughly assessed prior to discharge to bring this number down further. Personally, I would not change the routine followup date to 1 week, because most patients have far more complaints that are of little clinical importance than compared to 2 weeks after discharge.

Reference: Readmission of trauma patients in a nonacademic Level II trauma center. J Trauma 72(2):531-536, 2012.

The July 2021 Trauma MedEd Newsletter Is Live! Yet More Potpourri

I’ve put together another issue of miscellaneous, interesting stuff!

In this issue, learn about:

  • The effect of ambulance deceleration on ICP in head injury patients
  • An interesting technique for sealing vacuum systems applied around external fixators
  • An analysis of thrombotic events following TXA administration
  • The utility of a second head CT in patients taking DOACs

To download the current issue, just click here!

Or copy this link into your browser: https://www.traumameded.com/courses/more-potpourri-july-21/

This newsletter was released to subscribers over a week ago. If you would like to be the first to get your hands on future newsletters, just click here to subscribe!

 

Liver Laceration And Liver Function Tests

Over the years I’ve seen a number of trauma professionals, both surgeons and emergency physicians, order liver transaminases (SGOT, SGPT) and bilirubin in patients with liver laceration. I’ve never been clear on why, so I decided to check it out. As it turns out, this is another one of those “old habits die hard” phenomena.

Liver lacerations, by definition, are disruptions of the liver parenchyma. Liver tissue and bile ducts of various size are both injured. Is it reasonable to expect that liver function tests would be elevated? A review of the literature follows the typical pattern. Old studies with very few patients.

From personal hands-on observations, the liver tissue itself tears easily, but the ducts are a lot tougher. It is fairly common to see small, intact ducts bridging small tears in the substance of the liver. However, larger injuries can certainly disrupt major ducts, leading to major problems. But I’ve never seen obstructive problems develop from this injury.

A number of papers (very small, retrospective series) have shown that transaminases can rise with liver laceration. However, they do not rise reliably enough to be a good predictor of either having an injury, or the degree of injury. Similarly, bilirubin can be elevated, but usually not as a direct result of the injury. The most common causes are breakdown of transfused or extravasated blood, or from critical care issues like sepsis, infection, and shock.

Bottom line: Don’t bother to get liver function tests in patients with known or suspected injury. Only a CT scan can help you find and/or grade the injury. And never blame an elevated bilirubin on the injury. Start searching for other causes, because they will end up being much more clinically significant.

References:

  • Evaluation of liver function tests in screening for intra-abdominal injuries. Ann Emerg Med 20(8):838-841, 1991.
  • Markers for occult liver injury in cases of physical abuse in children. Pediatrics 89(2):274-278.
  • Combination of white blood cell count with liver enzymes in the diagnosis of blunt liver laceration. Am J Emerg Med 28(9):1024-1029, 2010.