Category Archives: Abstracts

Best Of AAST 2022 #7: Funding State Trauma Systems

As of about 10 years ago, every state in the US has implemented a state trauma system. The way these systems are funded and their sources vary widely. Most receive their funds via some combination of a line item in the budget, grants, or fees levied on state residents. The total per capita funding amount can be calculated based on the total dollars received divided by the state population.

The per capita funding across the US varies widely. Some provide very little assistance while others are much more generous. I have visited trauma centers in nearly every state and have witnessed the difficulties many state trauma systems face due to funding shortfalls.

Does financial support have an impact on trauma care? A better question is, do state systems have an impact on trauma care? The literature on that last question tells us the answer is a resounding yes. We assume that having some money improves what the system can do. But that’s just an assumption. Until now.

The group at Northwestern University did a deep dive into the financial support of state trauma systems to address this question. Their goal was to measure the impact of it on something easily measurable: mortality. They selected five states to study based upon their broad geographic and demographic variability and the availability of comprehensive data for analysis.

Two states (MA, NY) allocated $0.00 per capita trauma funding, and three provided between $0.09 and $1.80 per capita.  The authors analyzed data from comprehensive patient encounter databases from these states. Their primary goal was to compare mortality differences between the two levels of support. They were also able to link ED and inpatient encounters and analyze triage decisions for appropriateness.

Here are the factoids:

  • Nearly a quarter of a million patients with ISS > 15 were analyzed over a study period of two years
  • Median age was 72 and ISS was 17 (older with significant injuries)
  • Trauma mortality was significantly decreased in the states that provided financial support compared with those that did not (odds ratio 0.75)
  • All triage levels were associated with a similar decrease in mortality (appropriate triage to a Level I or II center, undertriage admitted to a Level III or IV center, and re-triage (emergent transfer from an ED to a Level I or II center))
  • The best improvement in mortality was seen in re-triaged patients in funded states (odds ratio of 0.63)

The authors concluded that state system funding was associated with lower mortality in severely injured patients and that increasing funding may facilitate it.

Bottom line: Several papers have been written showing the benefit of having a trauma system, and all of the US has bought into this concept. However, funding of these systems varies widely by state. The assumption (up to now) has been that just having a system is enough. This abstract goes a step further and suggests that actually paying for it is important, too. 

The authors performed quite of bit of data manipulation and used some sophisticated statistical tools that I am not familiar with. However, the authors are certainly qualified, and I am going to assume that the analysis was sound. 

The one important point to keep in mind is that this paper is one of the first of its kind but can only show association, not causation. Nevertheless, it is an important contribution to the trauma system literature. It will definitely prompt additional research which will hopefully corroborate the results. This line of work should give state systems the ammunition to approach their legislatures to open the pocketbook and improve the outcomes of their residents. Mortality reductions of 25-37% cannot be ignored!

Here are my questions and comments for the authors/presenters:

  1. Please explain the data sources you used and the analysis (briefly). These are very comprehensive databases and appear to contain a wealth of data. Tell us why you chose them, how you linked them, and explain your analyses.
  2. Why limit your analyses to these five states? Could you have found some with even higher levels of support that would drive your point home even better?
  3. Be sure to provide more detail on your analysis of triage status. There are some important lessons to be learned here regarding state triage criteria vs mortality.
  4. Are you planning any additional similar studies? This is important work that will help state systems obtain a more appropriate level of support.

This is an intriguing abstract that should prompt additional research regarding state trauma system funding. 

Reference: THE IMPACT OF STATE TRAUMA FUNDING ON TRIAGE AND MORTALITY OF TRAUMA PATIENTS. Plenary paper #38, AAST 2022.

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Best Of AAST 2022 #6: The “Missed” Splenic Pseudoaneurysm

Like so many things in trauma, there are two camps when it comes to repeat CT scan after solid organ injury: the believers vs the non-believers. In my experience, a minority of US trauma centers incorporate this repeat CT study in their practice guidelines. 

Yet the question keeps coming up in the literature. Earlier this year, I reviewed a paper from the University of Cincinnati from a group of believers. I was not very kind, and you can read the review here. The biggest problem with most believer papers is that they cite very old literature that overstates the incidence of delayed hemorrhage. They then use this to justify an extra CT scan to find more of these “dangerous” pseudoaneurysms. Unfortunately, those old papers are just not very good and many overstate the problem.

So let’s look at this year’s abstract from the LAC+USC group. They open by stating that the natural history is unclear but that “risk for spontaneous rupture and exsanguination exist.” The authors sought to further define the utility of using a delayed CT angiogram (dCTA) in diagnosing and triggering intervention after high-grade blunt solid organ injury.

They performed a retrospective study of all patients arriving at their Level I center over a nearly five year period with a Grade 3 or higher injury to liver, spleen, or kidney. They excluded the young, patients transferred in, early deaths, and patients who underwent immediate operation on their spleen or kidney. The primary outcome was intervention triggered by the dCTA.

Here are the factoids:

  • A total of 349 patients with 395 high grade solid organ injuries were analyzed (42% liver, 30% spleen, 28% kidney)
  • Median injury grade for each organ was 3
  • Initial management was “typically” nonoperative or angioembolization (liver 83%, spleen 95%, kidney 89%)
  • Delayed CT angiogram was typically performed on day 4 and identified a lesion in 16 spleen, 10 liver, and 6 renal injuries
  • The dCTA prompted an intervention in 12 spleen, 8 liver, and 5 kidney injuries

The authors conclude that delayed CTA identified a significant number of vascular lesions requiring endovascular or surgical intervention. They recommend further examination and consideration of universal screening to avoid missing these pesky pseudoaneurysms.

Bottom line: Once again, we have a paper that conflates finding a pseudoaneurysm with the need to get rid of it. Granted, I was always taught that pseudoaneurysms (in adults) found on initial CT required an intervention. In the old days of “delayed splenic rupture” a pseudoaneurysm was the likely culprit. 

But the majority of centers do not go looking for pseudoaneurysms days later. And there are precious few patients coming back with delayed hemorrhage after discharge. So what gives?

Could it be that there is a difference between a “fresh” pseudoaneurysm and a “delayed” one? Perhaps the fresh ones portend a real risk of bleeding, but delayed ones are just a normal part of the healing process and rarely bleed? We just don’t know for sure.

This paper shows that if you look for a delayed pseudoaneurysm you will find them. And at this center, if you find them you will be compelled to angioembolize or even operate on them. Yet we really don’t know if that is necessary. It certainly adds to length of stay and hospital charges.

My take is that we desperately need a broad tally of patients discharged with a liver or spleen injury who return within a few weeks for bleeding complications. I would exclude kidneys because they act so differently. And I would not look at all returns because most liver injury readmissions are for bile problems. Just focus on readmissions for bleeding. Once we see what the real incidence is, we can decide whether these pseudoaneurysms are a problem significant enough to pursue with delayed scans, etc.

Here are my questions for the authors and presenter:

  1. What is your assessment of the incidence of delayed rupture and exsanguination? Have you read through the old papers in detail to assure yourselves that they are actually correct?
  2. Do you hold patients in the hospital for their delayed CT angiogram? The studies were typically performed on days 3-7. Do you really keep your solid organ injured patients in the hospital that long? At our center, a grade 3 injury could be discharged home in two days!
  3. How do you decide to take a patient to interventional radiology or the OR after the delayed CT? Is it an unwritten rule? It seemed like most, but not all, had some type of intervention. A (very) few had the lesion but nothing was done. Please explain the difference.

This is an interesting paper just because of the intuitive leap it makes from pseudoaneurysm to intervention. I’m anticipating your presentation so I can hear all the details.

Reference: PSEUDOANEURYSMS AFTER HIGH GRADE BLUNT SOLID ORGAN INJURY AND THE UTILITY OF DELAYED CT ANGIOGRAPHY. Plenary paper #34, AAST 2022.

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Best Of AAST 2022 #5: Traumatic Subarachnoid Hemorrhage

Traditionally, just about any type of intracranial hemorrhage (ICH) prompts a thorough neurological investigation and frequently involves a neurosurgery consultation. Subarachnoid hemorrhage (SAH) is one type of ICH that has historically demonstrated very few adverse consequences. Yet the custom of performing a time-consuming and expensive evaluation has persisted.

Over the past few years, the literature about the lack of utility of this practice has been growing. Many trauma centers (including my own at Regions Hospital) have simplified the evaluation of traumatic SAH. We have actually come to a point that we don’t even admit most of these patients. And if we are not going to admit them, why should we even accept them in transfer from other hospitals?

The trauma group at Lehigh Valley in Pennsylvania performed a five-year review of their own hospital experience (Level I trauma center) from 2015-2019. They wanted to answer the question about the necessity of transferring SAH patients to a higher-level trauma center for evaluation. They limited the study to patients with an isolated SAH. These patients were evaluated for factors that would indicate the potential for a worsening repeat CT scan.

Here are the factoids:

  • The study patients were older (mean 73 years) with a slight preponderance of females
  • ISS was low (mean 5) as would be expected for an isolated injury
  • Slightly more than half (57%) were transferred from other hospitals
  • A total of 350 patients were reviewed, and 97% had a neurosurgery consult
  • Only one patient required neurosurgical intervention, and four died in hospital
  • A total of 311 patients had a repeat CT scan and 16 showed a worse result
  • Higher AIS head was associated with a worse result

The authors concluded that it is safe to manage traumatic SAH without transfer to a higher level trauma center.  They also suggest that neurosurgical consultation is not needed and that repeat imaging may not be very useful.

Bottom line: This abstract conforms to my own opinion, so I have to take great care not to succumb to my confirmation bias. The authors found that nearly no one needed neurosurgical intervention and concluded that a neurosurgical consult is probably not needed. This is all based on a low incidence of progression and few adverse events. I agree totally.

But I also think that referring hospitals will find these few adverse events and progressions troubling. Remember, 16 patients had a worse scan,  four died during their hospital stay, and one needed an operation. Thus, it will be very important for the authors to explain the details of these patients to assuage any fears that they might deteriorate in the outside hospital ED. 

My own experience indicates that “worsening CT” is typically just a slightly larger SAH and not the sudden development of subdural or epidural blood. This is more likely to happen in patients on thinners and they should be excluded from this pool anyway. They have very specific evaluation needs.

Based on recent published literature and our own clinical experience, the Regions trauma program discharges any patient with traumatic SAH who is not on thinners and has a GCS 15. They are given instructions to follow up with their primary care provider, and to schedule a TBI clinic appointment if they feel they have any persistent post-concussive symptoms. And because of this practice, the ED will not accept transfer of patients with this isolated injury.

You can download a copy of the protocol here.

Here are my questions for the authors and presenter:

  1. Please provide details on the patients with CT progression, operation, and death. We need to know if these were serious CT changes, or just incidental findings and complications from other causes.
  2. How successful have you been at resisting transfers in? Most referring centers are initially “not comfortable” with these patients, even though they can easily follow our simple evaluation guideline. It takes time and education to bring them into the fold.

I enjoyed this abstract and await the details to come in the presentation!

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Best of AAST 2022 #4: The “Hybrid ER” – Again?

Two years ago, an abstract was presented at this meeting describing the concept of the “hybrid ER.” Check it out using this link. This concept was pioneered in Japan, and consists of a special trauma resuscitation room in the ED with everything but an operating room built into it. It’s possible to perform whole-body CT scan, interventional procedures, and REBOA without moving the patient. Here’s a picture from that abstract:

A = CT scanner   B = CT exam table   C = movable C-arm   D = monitor screen   E = ultrasound   F = ventilator

In that abstract, about a thousand patients were compared with two thirds in the hybrid ER group and one third undergoing conventional evaluation. The authors concluded that mortality was significantly improved in the hybrid ER group, and even more so in high ISS patients.

I had a lot of questions for that abstract that were answered in the subsequently published manuscript (reference 2). The authors have updated their experience using new data from the last five years. They created a new approach to resuscitation that is different than the usual ATLS sequence for select patients. Here’s the algorithm they used:

The primary survey is completed, then the patient undergoes a quick whole body CT scan. After that, the secondary survey progresses and any necessary emergency procedures are performed.

In this abstract, the authors compared a group of 46 patients who underwent standard ATLS evaluation with 49 who received the expedited process, which they termed CT First Resuscitation (CTFR). All patients had presumptive hemorrhagic shock based on prehospital vital signs. The authors analyzed injury patterns, interventions performed, timing, adverse events, and outcome. Demographics and injury severity were similar in the two groups.

Here are the factoids:

  • Time to CT in the CTFR group was significantly shorter (1.5 min vs 15 min)
  • The expedited scan settings for CTFR resulted in blindingly fast scan times (median 56 seconds)
  • None of the CTFR patients decompensated during the scan process
  • There was no difference in mortality between CTFR and standard evaluation (14% vs 4%, p=.1)
  • There was no difference in time to hemostatic intervention (56 vs 59 minutes)
  • There was no difference in red cell transfusions (no units in either group)

The authors concluded that CTFR expedited trauma management without adverse effects, and there was no increase in mortality. They, or course, recommended further study.

Bottom line: Several trauma surgeons from a variety of centers wrote an invited commentary last year (reference 3) expressing their excitement about this concept. Reducing time to definitive control of hemorrhage has been repeatedly shown to improve survival. The hybrid ER is one way of reducing those times by eliminating most of the time needed to move the patient about and providing everything but an operating room in the emergency department.

But they also recognized the limitations of this concept. The changes to the ED physical plant are extreme and involve the installation of very expensive equipment that must be heavily shielded from the rest of the emergency department. There are also significant differences in physician training and hospital reimbursement between Japan and the US. This will probably severely limit the adoption of this technology in the States.

I believe that this is an important study showing the feasibility of this method of evaluation. Unfortunately, it does not allow us to draw any real conclusions about safety and efficacy due to the low numbers of patients enrolled. I agree with the authors that a larger study should be performed so we can truly determine whether this concept can possibly be applied outside of Japan.

Here are my questions for the authors / presenter:

  1. Did you perform a power analysis? I doubt that the sample size reported would allow for any findings of statistical significance with the exception of huge differences like time to CT.
  2. How do you protect the trauma team from radiation exposure? Since these patients are in shock when they arrive, I assume that the team cannot leave the room. CT scan radiation exposure of the team is significantly higher than a chest and pelvis x-ray. Repeated team exposure may pose risks.
  3. Does the trend toward higher mortality in the CTFR group trouble you? Sure, it is not statistically significant. But it is approaching significance with a small sample group.
  4. Why didn’t the CTFR group have more rapid hemostatic intervention? One would think these early results could help move the patient to an OR more quickly. And why did it take an hour? Isn’t that a long time?
  5. Why didn’t your patients receive any blood? Weren’t they supposed to be at risk for hemorrhagic shock? How did you treat it without blood? Perhaps your selection criteria need to be tweaked.

This is a nice follow on study from the previous presentation two years ago. It could be an exciting advance in resuscitation, but we need much more info to pass judgement. I’m looking forward to the presentation.

References:

  1. COMPUTED TOMOGRAPHY FIRST RESUSCITATION WITH HYBRID EMERGENCY ROOM FOR SEVERELY INJURED PATIENTS. Plenary paper #25, AAST 2022.
  2. Hybrid emergency room shows maximum effect on trauma resuscitation when used in patients with higher severity. J Trauma Acute Care Surg. 2021 Feb 1;90(2):232-239.
  3. Time to Hemorrhage Control in a Hybrid ER System: Is It Time to Change? Shock. 2021 Dec 1;56(1S):16-21.
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Best of AAST 2022 #3: VTE Risk After Spinal Cord Injury

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:

  1. 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.
  2. 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:

  1. Tell us about the statistics. How did you calculate the rates that are cited in the paper? I can’t figure out the math.
  2. 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?”
  3. 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.

 

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