Category Archives: Prevention

Best of AAST 2022 #3: VTE Risk After Spinal Cord Injury

September 8, 2022 The Trauma Pro Leave a comment

Venous thromboembolism (VTE) is always a concern in trauma patients. But patients with spine fractures are at much higher risk and those with spinal cord injuries on top of it even more so. The best tool we have right now for prevention is chemoprophylaxis with some type of heparin. Unfortunately, VTE prophylaxis is commonly interrupted or delayed due to concern for causing bleeding. These concerns may relate to concomitant injuries (e.g. solid organ injury) or necessary surgical procedures.

About five years ago, the Army provided a $4.25M grant to fund the Coalition of Leaders in Thromboembolism (CLOTT) study group. It involved contributions from 17 Level I trauma centers attempting to look at the incidence, treatment, and prevention of VTE after trauma. Additional phases are now under way to look at offshoot discoveries from the original research.

A group from the University of California – Sand Diego performed a secondary analysis of a subset of the CLOTT study in patients age 18-40 over a three year period. Patients with a diagnosis of spinal cord injury who were admitted for at least 48 hours were analyzed. The authors focused on timing of the start of VTE prophylaxis, VTE rates, and missed prophylactic dosing. They also reviewed any bleeding complications.

Here are the factoids:

From the entire CLOTT study group, 343 met criteria and had sustained a spinal cord injury
Most subjects were young (mean 29) and male (77%) and had sustained blunt injury (79%)
A total of 44 patients (13%) developed VTE – 30 DVT, 3 pulmonary embolism, and 11 pulmonary thrombus
Only one in five patients started chemo-prophylaxis prior to 24 hours, and this increased to about 50% at 48 hours (!)
VTE rate overall was 9.6% (?)
The rate trended lower in patients who received their prophylaxis within 48 hours (7% vs 13% but not significant)
Missed doses of chemo-prophylaxis were common (30%) and were associated with higher VTE rates

The authors concluded that VTE rates are high in these patients and early chemoprophylaxis is critical in limiting thrombotic events.

Bottom line: Hmm. This abstract confuses me a little. Actually, I had expected a higher VTE rate in this patient group. I’ve seen reports 2x to 3x higher than reported here. But yes, I do believe that these patients are at high risk.

And looking at the chart, it appears that there is a trend toward higher rates in patients who missed doses rather than those who did not. But the real questions are:

Is it real? That is, are those differences significant? The only analysis in the abstract compares early vs late administration and that is trending toward significance but didn’t quite make it there. And remember that the graph you are looking at cuts off at 18% which makes the differences look much bigger.
What can we do about it? Many trauma professionals are still uncomfortable giving prophylaxis early because of fear of bleeding. This is probably unwarranted, but we just don’t have enough hard data to say so. Anecdotal data about surgeons operating uneventfully through chemoprophylaxis is growing, though.

My impression of this study is that it shows some interesting trends, but probably doesn’t include enough subjects to know the real answer for sure.

Here are my questions for the authors / presenter:

Tell us about the statistics. How did you calculate the rates that are cited in the paper? I can’t figure out the math.
What is the difference between a pulmonary embolism and pulmonary thrombus? Is it merely the presence or absence of concomitant clot in the legs or pelvis? Why distinguish between the two if you are lumping them all together as “VTE?”
What are we to do with this data? Obviously, everyone wants to provide VTE prophylaxis in a timely manner. But there are a raft of reasons why clinicians are “not comfortable” doing it. Any suggestions?

Reference: VENOUS THROMBOEMBOLISM RISK AFTER SPINAL CORD INJURY: A SECONDARY ANALYSIS OF THE CLOTT STUDY. Plenary Paper 23, AAST 2022.

Abstracts, Prevention

Best Of AAST 2021: Identifying Risk For Elderly Falls

September 13, 2021 The Trauma Pro Leave a comment

Over the past 20 years, falls have become the most common mechanism of injury at most trauma centers. In fact, many centers count twice as many falls as motor vehicle crashes! The problem with working in a trauma center is that we tend to see patients at risk for falls only after they have fallen.

The group at Butterworth Hospital attempted to determine if there was a way to identify patients at risk for falls earlier. They postulated that many of these patients may have experienced a fall within the past year, identifying them as at high risk for yet another. They retrospectively reviewed their trauma registry data for a three year period. Specifically, they wanted to identify how many of those had suffered earlier falls and what happened to them over time.

Here are the factoids:

A total of 597 patients were also admitted due to a fall during the year prior to their index admission
Only 2% had falls prevention teaching after the previous admission
About a third of patients fell again within a year after the index admission, and 20% were admitted again
The patients were assessed using the Hester-Davis score (see below), and patients who were identified by it as high risk were more likely to be readmitted or die
Overall mortality at 12 months was about 20%

The authors were surprised that so many of their falls patients had been previously admitted for a fall. They recognized that it presents a major prevention opportunity, and recommend these patients undergo some type of activity before and/or after discharge.

Note: The Hester Davis Fall Risk Scale (HDFRS) includes factors of age, date of last known fall, mobility, medications, mental status, toileting needs, volume/electrolyte status, communication/sensory, and behavior with the option to choose multiple options per risk category; a score of seven to ten indicates low fall risk, eleven to fourteen indicates moderate fall risk, and greater than fifteen indicates high fall risk.

Bottom line: This is a straightforward single-hospital registry study. Even though it reflects the experience of a single rural trauma center, the results are applicable to most others. It confirms that any fall in the elderly should be considered a sentinel event which has a good chance leading to death within a year.

Here’s the way I see it:

“You fall, you die”

It is very important that every trauma center identify these patients when they arrive, and apply prevention efforts while in the hospital or hook them up with activities after discharge. And if you don’t have such a program included in your injury prevention activities, you should! It’s the most common mechanism seen by trauma centers, hands down!

I have only one suggestion for the presenter and authors:

The concept of being “at risk” was not clear to me. Did this mean that you looked back one year for each admission to see if there was an admission for a fall? Or did you just get the history of a fall from the previous admission? It looks like you identified an index admission, then looked back a year to see if the patient should be included in this study. Then you looked forward a year to see if there was yet another admission and/or death. Is this correct? Please clarify during your presentation at the meeting.

Reference: FALL RISK IDENTIFICATION THROUGHOUT THE
CONTINUUM OF CARE. AAST 2021, Oral abstract #18.

Prevention

Best of EAST #5: Elderly Falls And Vision Problems

January 6, 2021 The Trauma Pro Leave a comment

Elderly falls have become a huge problem. There isn’t a night that goes by that we don’t admit at least two or three at our trauma center. There are at least a dozen factors that have been identified that are associated with falls, including:

Medications
Bone and muscle loss
Underlying medical conditions
Gait problems
Throw rugs and other environmental hazards
Visual problems

And many more! But let’s focus on that last one. Vision problems can be due to primary disease, such as glaucoma, or from lack of adequate correction of those problems, such as decreased visual acuity.

The group at West Virginia University is presenting a prevention paper next week. They prospectively studied patients older than 60 years who were admitted to their trauma service over a one year period. They wanted to determine the prevalence of undertreated or undiagnosed eye disease in the population, and to find out if using readily available screening tests could detect this and assist in prevention efforts.

A dilated ophthalmic exam was performed and used as the gold standard. The results were compared to a screening app administered by a trauma provider via an iPad (the eyeTests Easy app). This app can be used to test for visual acuity, macular degeneration, near vision, and astigmatism.

Here are the factoids:

A total of 96 patients were enrolled, with an average age of 75 and a predominant mechanism of fall in 79%
Significant abnormal vision was undiagnosed in 39% of patients and undertreated in 14%
The trauma provider app exam was 94% sensitive and 92% specific
Correlation was best on pupil exam (86%), visual fields (58%), and the macular degeneration test (52%)
A combination of visual fields and the Amsler grid were associated with significant abnormal vision

The authors concluded that unrecognized visual problems are common, and are present in 53% of their elderly trauma admissions. They also state the the trauma provider exam can identify abnormalities in “most cases” and can identify those who should be screened by an ophthalmologist.

My comments: This is an interesting study that compares a simple, app-based screen with a more sophisticated ophthalmology exam. However, it is not clear what “significant abnormal vision (SAV)” really is. The sensitivity and specificity numbers cited depend on this definition. Is it a positive answer to one of the screening questions? Evidence of macular degeneration? If so, how much? I’m sure that a lot of the elderly (and younger) population have some small irregularities in their vision, but what makes it significant?

The study does show that the app can be used as a screening tool due to the congruence with the “gold standard” ophthalmologic exam. And given that vision is one of the major factors associated with falls risk, it may be a cost-effective tool for reducing it.

Here are my questions for the authors and presenter:

What is you exact definition of “significant abnormal vision?” This is critical, because it determines the significance of the rest of your results. If the threshold is set too low, you will detect many anomalies but they may not be clinically significant. This definition needs to be as objective as possible so others can duplicate and take advantage of your work.
What do you recommend for workflow to incorporate this tool? Who should do it and when? Should the user focus on particular portions of the app (e.g. Amsler and visual fields, acuity)?
Describe your future plans for the longitudinal study mentioned in the abstract.

This is very interesting prevention work. I look forward to the nitty gritty details next week!

Reference: Stop the fall: identifying the 50% of geriatric trauma patients with significant vision loss. EAST 2021, Paper 11.

Abstracts, Prevention

Best Of EAST #6: Uber / Lyft vs Drunk Driving

January 9, 2020 The Trauma Pro Leave a comment

Ride share services like Uber and Lyft are now pretty much ubiquitous. It’s so easy to get a ride these days one would think that the incidence of car crashes due to drunk driving should be declining, right?

Well, nobody knows for sure. But the group at Tulane decided to look at their own data for alcohol-related car crashes over a seven year period. They also combed regional traffic databases for more information and compared the data from pre- to post- arrival of ride share services.

Here are the factoids:

There were 1474 patients involved in alcohol-related crashes (ARC)
The proportion of alcohol-related ARCs decreased significantly from 39% to 29%
The overall annual incidence of fatal ARCs seen at Tulane decreased significantly from 11.6 to 5, and also decreased significantly within the region
However, the incidence of ARCs only decreased within the 21-24 year age group(!)

My comment: This is very interesting work! The statistics appear to be sound and the number sufficiently large. It shows that it might be possible to decrease drunk driving injuries using methods other that the usual prevention efforts. It is puzzling, though, that the effect is only seen in a very narrow age group in the population. Practically everyone can use a ride-hailing app these days. Even I do!

Here are my questions for the authors and presenter:

How do you explain the very narrow age-range that appears to be affected? Remember, this study shows an association, not cause and effect. Could it be that something else is reducing alcohol-related crashes in this specific age group, and it has nothing to do with ride share availability? What else could it be?
How can this decrease in 21-24 year olds hold when there was such a significant decrease in overall alcohol-related crashes? Was everyone driving around New Orleans in that age group? Otherwise, how can this be explained?

I am fascinated by this study. But it’s going to be difficult to separate out other confounding variables and causes to be able to point definitively to any benefit from ride share services.

Reference: Do ride sharing services affect the incidence of alcohol-related motor vehicle collisions? EAST Annual Assembly abstract #22, 2020.

Pharmacy, Prevention

Anticoagulants And The Elderly: Are They Being Appropriately Treated?

October 13, 2017 The Trauma Pro Leave a comment

About 2.3 million people, or a bit less than 1% of the US population, have atrial fibrillation. This condition is commonly managed with anticoagulants to reduce the risk of stroke. Unfortunately, the elderly represent a large subset of those with a-fib. And the older we get, the more likely we are to fall. About half of those over 80 will fall once a year.

Are all of these elderly patients being treated with anticoagulants appropriately? Several scoring systems have been developed that allow us to predict the likelihood of ischemic stroke. Looking at it another way, they allow us to judge the appropriateness of using an anticoagulant to prevent such an event.

The original CHADS2 score was developed using retrospective Medicare data in the US. The newer CHA2DS2-VASC score used prospective data from multiple countries. However, the accuracy is about the same as the original CHADS2 score. But because the newer system has three more variables, it adds a few more people to the high-risk group who should receive an anticoagulant.

The higher the CHA2DS2-VASC score, the more likely one is to have an ischemic stroke. The threshold to justify anticoagulation seems to vary a bit, with some saying >1 and others going with >2. Here’s a chart that shows how the stroke risk increases.

Stroke risk per year with CHA2DS2-VASC score

Whereas CHA2DS2-VASC predicts the risk of clotting (ischemic stroke), the HAS-BLED score looks at the risk of bleeding. It includes clinical conditions, labile INR, and concomitant use of NSAIDs, aspirin or alcohol, but not a history of falls.

Proper management of atrial fibrillation in the elderly must carefully balance both of these risks to reduce potential harm as much as possible. A HAS-BLED score of >3 indicates a need to clinically review the risk-benefit ratio of anticoagulation. It does not provide an absolute threshold to stop it.

A group at Henry Ford Hospital in Detroit, a Level I trauma center, retrospectively reviewed their experience with patients who fell while taking an anticoagulant for atrial fibrillation. They calculated CHA2DS2-VASC and HAS-BLED for each and evaluated the appropriateness of their anticoagulation regimen.

Here are the factoids:

A total of 242 patients were reviewed, and the average age was 78
The average CHA2DS2-VASC score was 5, and the average HAS-BLED was 3
Only 1.6% were considered to be receiving an anticoagulant inappropriately (CHA2DS2-VASC 0 or 1)
Nearly 9% of patients were dead 30 days after the fall

Bottom line: The authors found that their population was appropriately anticoagulated. But they also noted that the morbidity and mortality risk was high, and was independent of age and comorbidities.

There are tools available to help us judge whether an elderly patient should be taking an anticoagulant for atrial fibrillation. The tool for predicting bleeding risk, however, is not as good for trauma patients. It ignores the added risk from falling, which is very common in the elderly.

Every patient admitted to the trauma service after a fall should have a critical assessment of their need for anticoagulation. The specific drug they are taking (reversible vs irreversible) should also be examined. If there is any question regarding appropriateness, the primary care provider should be contacted personally to discuss and modify their drug regimen. Don’t just rely on them reading the hospital discharge summary. Falls can be and are frequently fatal, just not immediately. Inappropriate use of anticoagulants can certainly contribute to this problem, so do your part to reduce that risk.

Related links and posts:

Reference: Falls, anticoagulation, and the elderly: are we inappropriately treating atrial fibrillation in this high-risk population? JACS 225(4S1):S53-S54, 2017.

Home of the Trauma Professional's Blog