All posts by The Trauma Pro

Critical care

The Decision To Stop In Geriatric Trauma

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Traumatic injury is a continuum ranging from very minor to immediately fatal. The mortality rate along that continuum rises exponentially as the Injury Severity Score (ISS) increases. We long ago moved away from the philosophy of keeping someone alive at all costs to embracing the concept of quality of life. We have become more thoughtful about considering patient and family input in difficult cases.

This occurs more frequently when we treat geriatric patients. The mortality for a given ISS increases even more steeply than in younger patients and continues to accelerate for each decade of life. It is becoming routine to have goals of care discussions with patients and their families in most areas of medicine. Although commonplace in specialties like oncology, it is not as common in trauma care.

Withdrawal of life support is one of the endpoints of these goals of care discussions. However, making such a decision with the patient and/or family is challenging. Too soon, and there may be missed opportunities for recovery. Too late, and the patient and family may be further traumatized by futile or undesired care.

Is it possible to identify the common factors that predict appropriate withdrawal of care? The University of Arizona at Tucson group analyzed the Trauma Quality Improvement Program (TQIP) database on withdrawal of care from 2017-2019. The authors included only patients aged 65 and older. They sought to identify the predictors of care withdrawal. They also calculated their frailty index to gauge its impact on withdrawal decision-making.

Here are the factoids:

  • Over 150K patients were included in the analysis, with a mean age of 77 and predominantly blunt mechanism (97%)
  • About 19% were judged to be frail by applying an 11-variable frailty index
  • About 1 in 10 had withdrawal of support
  • Factors that increased the likelihood of support withdrawal were increasing age (1.4x more likely), frailty (1.4x), impaired activities of daily living (ADLs) (2.6x), and ventilator requirement (13x)
  • There was no difference between Level I and Level II trauma centers
  • Only 9% of patients had an advance directive
  • Interestingly, 19% of patients who had support withdrawn did not die

Bottom line: The authors only attempted to describe what factors were more likely to be present in patients who underwent withdrawal of care. A simple TQIP database analysis does not contain the data necessary to reliably develop suggested criteria. However, this study is very valuable because it offers a possible basic framework.

Age, frailty, ADLs, and vent dependence were the major variables noted. This alone may make the trauma professional more confident in approaching the family in cases where there is no advance directive. Which, unfortunately, is the majority of patients. 

But more importantly, we really need to define when the most appropriate time for the withdrawal discussion to occur. It requires a careful balance between potentially stopping too soon and persisting into futility.

In my next post, I’ll review another paper on this topic, using TQIP data, also published earlier this year. I’ll compare and contrast the results and see if we can get a clearer picture of how to proceed in the challenging cases.

Reference: The final decision among the injured elderly, to stop or to continue? Predictors of withdrawal of life-supporting treatment. J Trauma Acute Care Surg. 2023 Jun 1;94(6):778-783. 

Practice guidelines, Solid organ

New EAST Practice Guideline: Spleen Vaccines After Angioembolization

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I am trying to figure out how I missed it! The Eastern Association for the Surgery of Trauma (EAST) snuck a new practice management guideline into the Injury journal last fall. And it desperately tries to answer a question that has been hanging around for several years. Do we vaccinate spleen injury patients who undergo angioembolization or not?

I’ve been pondering this for some time and have reached my own conclusion based on some very old literature. Decades ago, we figured out that removing the spleen significantly affects immune function. Splenectomy patients are known to be more susceptible to encapsulated bacteria like Neisseria meningiditis, Streptococcus pneumoniae, and Haemophilus influenzae. Most trauma centers routinely vaccinate these patients before they are discharged home.

With the more recent emphasis on splenic salvage and nonoperative management of injury to this organ, angioembolization has become commonplace. This technique can be done in two ways: proximal and distal. Proximal embolization blocks the splenic artery, so there is no further blood flow to the spleen through it. Distal embolization (selective or super-selective) strives to block flow to very specific areas of the organ.

Do we need to give the vaccines if we cut off blood flow to pieces of the spleen or the main splenic artery? Based on my appreciation of very old splenectomy and partial splenectomy papers, it looked like we should in some cases. One report showed that splenic protection from encapsulated bacteria required about 50% of the spleen to be present and perfused by the splenic artery. This caveat stems from a time when we would perform a trauma splenectomy, dice the spleen up on the back table, and then implant a bunch of spleen cubes into the mesentery to try to provide some immune protection. Turns out that the pieces lived but didn’t do a damn thing.

My practice, then, has been to look at the fluoro images and estimate how much of the spleen was left. I would order the vaccines if a main splenic artery embolization (proximal) was performed. If a distal embolization were performed, I would eyeball the amount of devascularized spleen and give the vaccines if it looked like more than half was dark. Not very precise, I know.

But what would EAST say? They tried to perform a systematic review and meta-analysis of studies that compared outcomes in splenectomy vs. angioembolization patients. Unfortunately, there isn’t a lot of research material out there. So they settled on looking at papers that analyzed immune function, typically using B-cells, T-cells, and antibodies. The authors performed two comparisons: angioembolization vs. splenectomy and angioembolization vs. control.

Angioembolization vs. Splenectomy

These papers compared embolization patients who may or may not have spleen function to splenectomy patients who definitely have none. Embolization patients had fewer infectious complications during their hospital stay and better immune function using the indirect methods noted above. Unfortunately, the data quality was poor, with a significant risk of bias. There was no stratification of proximal vs. distal embolization. Nevertheless, this suggests that, at least overall, the embolization patients retained immune function.

Angioembolization vs. Controls

What about comparing embolization patients to spleen-injured patients who did not undergo any procedure? They should have normal function. Again, the quality of the very few papers available was low. But overall, there was no difference in immune function between the groups.

Bottom line: The EAST review team conditionally recommended against routine spleen vaccines after angioembolization for spleen injury. They concluded that immune function was maintained, so it should not be necessary.

What, you ask, about patients with proximal splenic embolization? The reality is that this only stops inflow from the splenic artery, and only for a few days or weeks. It may slowly resume over time. And it does nothing to the inflow from the short gastric arteries. Apparently, this is enough to provide immune protection against infection.

Whether this is actually true is open to debate. We have no idea if the numbers of T- and B-cells seen and the antibody titers are actually enough to avoid overwhelming post-splenectomy sepsis. And unfortunately, this condition is so rare that we will never accumulate enough cases to make a definitive statement.

But for now, it is probably okay to forgo the vaccines in patients undergoing angioembolization. Besides, the differing guidelines on which vaccines to use, when to give them, and when to schedule boosters were getting way out of hand! Please keep it simple!

Reference: Vaccination after spleen embolization: a practice management guideline from the Eastern Association for the Surgery of Trauma. Injury 53:3569-3574, 2022.

General

Crafting And Refining Your Massive Transfusion Protocol – Part 4

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It’s more on the massive transfusion protocol (MTP). I’ll continue today with MTP activation triggers.

What criteria should trigger your massive transfusion protocol? Sometimes, it’s obvious. The EMS report indicates that your incoming patient is in shock. Or there was notable blood loss at the scene. Or they have a mangled extremity and will need blood products in the OR, if not sooner.

But sometimes the need for ongoing and large quantities of blood sneaks up on you. The patient is doing well but has an unexplained pressure dip. And it happens again. You give one of your  uncrossmatched units of blood. It happens again. At some point, you come to the realization that you’ve given six units of blood and no plasma or other products! Ouch!

Many trauma centers have adopted MTP criteria like:

  • More than 4 units given over 4 hours
  • More that 10 units to be given over 24 hours
  • Loss of half a blood volume over 24 hours

I call these the “psychic power” criteria, because one must surely be prescient to know this information just shortly after the patient arrives. Don’t include criteria like these at your center!

Instead use some sort of objective criteria. A simple one is the use of any of your blood refrigerator products or emergency release blood, or a calculated score such as the ABC score or shock index (SI).

ABC score is the Assessment of Blood Consumption score and gives one point each for a heart rate > 120, SBP < 90, positive FAST, penetrating mechanism.  ACS score > 2 was predictive of requiring MTP with sensitivity and specificity of about 85%. Overtriage was about 15%.

Shock index (SI) is defined as the heart rate divided by the SBP. Normal values are in the range of 0.5 to 0.7. Need for MTP was found to increase to 2x for SI of 0.9, 4x with an SI of 1.1, and 7x with SI 1.3.

One paper compared these two systems retrospectively on 645 trauma activations over a 5-year period. They found that they both worked well with the following results:

  • Shock index > 1 – 68% sensitive 81% specific
  • ABC > 2 – 47% sensitive, 90% specific

The study suggests that shock index is more sensitive, and takes less technical skill to calculate. Bottom line: just pick the some objective criterion you are most comfortable with and use it!

Reference: Accuracy of shock index versus ABC score to predict need for massive transfusion in trauma patients. Injury 49(1): 15-19, 2018

Well folks, that’s it for the MTP series! Hope you enjoyed it. Feel free to email or leave a comment with any questions or suggestions!

Laboratory, Resuscitation

Crafting And Refining Your Massive Transfusion Protocol – Part 3

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Let’s continue with my series on the massive transfusion protocol (MTP). I’ll continue today with information on deactivating and analyzing your MTP.

Deactivation. There are two components to this: recognizing that high volume blood products are no longer needed, and communicating this with the blood bank. As bleeding comes under surgical control, and CBC and clotting parameters (and maybe TEG/ROTEM) normalize, the pace of transfusion slows, and ultimately stops. Until this happens, the MTP must stay active. Even a low level of product need should be met with coolers stocked with the appropriate ratios of products.

There are two ways to stop the MTP: the surgeon or their surrogate calls the blood bank (when no more blood products are to be used), or the blood bank calls the surgeon after the next cooler has been waiting for pickup for a finite period of time. This is typically about 30 minutes. It is extremely helpful if the exact deactivation time is recorded in the electronic medical record. However, this information can be obtained from the blood bank.

Analysis. It’s all over, and now the real fun begins. For most trauma centers, the blood bank maintains extensive data about every aspect of each MTP event. They record what units were released and when, when they were returned, which ones were used, were they at a safe temperature on return or were they wasted, and much, much more! Typically, one of the blood bank supervisors or a pathologist then compiles and reviews this data. What happens next varies by hospital.

Ideally, the information from every MTP activation gets passed on to the trauma program. Presentation at your transfusion committee is fine, but this data is most suitable for presentation at the trauma operations committee. And if significant variances are present (e.g. product ratios are way off) then it should also be discussed at your multidisciplinary trauma PI committee as well.

There are relatively few standard tools out there that allow the display of MTP data in an easily digestible form. Here are some of the key points that must be reviewed by the trauma PI program:

  • Demographics
  • Components used (for ratio analysis)
  • Lab values (INR, TEG, Hgb, etc)
  • Logistics
  • Waste

I am aware of two tools, the Broxton form and an MTP audit tool from the Australian National Blood Authority. The Broxton tool covers all the basics and includes some additional data points that cover activation criteria, TXA administration, and administration of uncrossmatched blood. Click here to check it out. The Australian tool is much more robust with more data points that make a lot of sense. You can download a copy by clicking here.

In the next post, I’ll continue with activation criteria for the MTP.

Laboratory, Resuscitation

Crafting And Refining Your Massive Transfusion Protocol – Part 2

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My series on the massive transfusion protocol (MTP) continues! Today, I’ll provide some tips on the logistics of your MTP.

MTP logistics include details such as who will be delivering the blood, what actually goes in each cooler, what ratios should be used, limitations imposed by the use of frozen plasma, and documentation. I’ll discuss details about ratios and FFP in the next Trauma MedEd newsletter.

The runners who travel between the blood bank and the patient need to be selected carefully. Blood bank tech? Not ideal because they’ve got more important work to do. ED or OR tech? Maybe, as long as you’ve got a reliable pool. Student or resident? Probably not, because they may not know their way to the blood bank, which is typically placed in the farthest corner of the basement as possible. One of the most creative solutions I’ve seen is the use of a hospital security officer. Think about it. They know the hospital layout cold, including that obscure corner where the blood bank is located. And there are plenty around all the time!

Documentation is critically important, both in the trauma bay and the blood bank. Trauma activations, especially ones requiring MTP, are very fast-moving and complex. Two sets of documentation are crucial: accurate records of blood product administration (on the trauma flow sheet), and documentation of just about everything else (in the blood bank). A specific timestamp on the trauma flow sheet that records the exact time of activation of MTP is a big plus.

What about coolers? I’ve seen everything used from uninsulated plastic buckets, picnic coolers, and pneumatic tube containers to large, self-contained rolling refrigeration units. The choice of container really boils down to cost vs waste. The cheaper the container is, the less insulated it is, the more likely that blood products will be discarded due to high temperature if not transfused promptly. The best blend of cost vs utility seems to be the good, old-fashioned picnic cooler. It’s very portable, reasonably cheap, and can be tested for temperature maintenance. Just be sure to secure a pouch to the outside to keep platelets at room temperature to maintain full functionality.

Here’s a sample MTP cooler that’s ready for use. The platelets are in the pouch on the left. Note the reminder to prompt the team to give TXA if not contraindicated. This is often forgotten in the heat of the trauma activation.

Who actually runs your MTP? In some ways, it should run itself. Coolers get delivered, products get transfused. However, some decision making is needed to decide how long to continue and whether any tweaking of product ratios needs to happen. In the emergency department, the surgeon or emergency physician can do this. But once a trauma patient arrives in the OR, that is no longer the case. The emergency physician was left behind in the ED and the surgeon is up to her elbows in trouble. What about the anesthesiologist? Nope, they are busy keeping the patient safely asleep, regulating rapid infusions, and actually administering the blood.

Most of the time, however, these two physicians actually end up running the MTP while multi-tasking at their other job. Unfortunately, this can lead to errors and delays. One best practice to consider: a highly trained trauma resuscitation nurse or advanced practice provider (APP) can run the MTP from the sidelines. They travel with the patient from ED to OR, managing the MTP the entire time. This offloads responsibility from busier people.

In the next post, I’ll continue with MTP deactivation and analysis.